KR102478061B1 - Diagnosis method of efficiency for rail pressure control valve - Google Patents

Abstract

The method for diagnosing the performance of the rail pressure regulating valve according to the present invention includes the steps of controlling the rail pressure regulating valve so that the pressure of the common rail reaches a required pressure; After the control step, the control unit cumulatively calculates the driving duty value and driving time of the rail pressure regulating valve driven until the common rail reaches the required pressure; Comparing, by the controller, the drive duty value and the drive time with preset set duty values and set times after the calculation step; and diagnosing, by the control unit, that the performance of the rail pressure control valve has deteriorated, when the driving duty value and the driving time are equal to or greater than the set duty value and the set time, respectively, as a result of performing the comparison step.

Description

Performance diagnosis method of rail pressure control valve {DIAGNOSIS METHOD OF EFFICIENCY FOR RAIL PRESSURE CONTROL VALVE}

The present invention relates to a method for precisely diagnosing the airtightness and operational performance of a rail pressure control valve.

In general, an electronic fuel injection system in a vehicle can inject fuel at a very high pressure into a cylinder compared to conventional mechanical fuel injection devices by applying a common rail, and the formation of pressure and injection of fuel are individually controlled. It is very advantageous in terms of exhaust gas regulation and noise, and can improve engine performance.

In the case of a common rail system without a high-pressure pump, a pumping injector that compresses and fills fuel at high pressure with a common rail and injects the fuel inside the common rail into a cylinder, and a non-pumping injector that injects fuel from the common rail into the cylinder; It consists of a rail pressure sensor for measuring the fuel pressure inside the common rail and a rail pressure control valve for controlling the fuel pressure inside the common rail.

Conventionally, the pressure control performance of the common rail was determined simply by using the value obtained by subtracting the pressure inside the common rail from the pressure requested by the common rail transmitted from the control unit, but misdiagnosis occurred when the vehicle rapidly accelerated and decelerated. However, there is a problem in that precise performance diagnosis cannot be performed according to engine load conditions.

The matters described as the background art above are only for improving understanding of the background of the present invention, and should not be taken as an admission that they correspond to prior art already known to those skilled in the art.

JP 2007-100624A

The present invention has been proposed to solve these problems, and by diagnosing the performance of the rail pressure regulating valve based on the driving duty value and operating time of the rail pressure regulating valve, it is possible to more precisely detect the abnormality of the rail pressure regulating valve. The purpose is to provide a method for diagnosing the performance of the rail pressure control valve.

According to the method for diagnosing the performance of a rail pressure regulating valve according to the present invention for achieving the above object, the control unit controls the rail pressure regulating valve so that the pressure of the common rail reaches a required pressure; After the controlling step, the control unit accumulatively calculating a driving duty value and a driving time of the rail pressure regulating valve driven until the common rail reaches a required pressure; Comparing, by the control unit, the driving duty value and the driving time with a predetermined set duty value and a set time, respectively, after the calculating step; and diagnosing, by the control unit, that the performance of the rail pressure control valve has deteriorated, when the driving duty value and the driving time are equal to or greater than the set duty value and the set time, respectively, as a result of performing the comparison step.

Before the control step, the control unit may further include determining whether a diagnosis condition of the rail pressure control valve is satisfied.

In the determining step, when the control unit detects a failure of at least one of a rail pressure sensor, a temperature sensor, and a pumping injector, it is determined that the diagnosis condition of the rail pressure control valve is not satisfied, and the control step is not performed. can be characterized.

In the determining step, the control unit controls the rail pressure regulating valve when at least one of the accelerator opening degree, vehicle speed, common rail pressure, engine speed, required fuel amount, and engine speed change rate satisfies a set value or condition. It may be characterized in that the control step is performed by determining that the diagnosis condition is satisfied.

In the determination step, the control unit determines that the diagnosis condition of the rail pressure control valve is satisfied when the difference between the actual pressure and the set pressure of the common rail is less than the set difference value after controlling the common rail to the set pressure. It may be characterized in that the control step is performed by doing so.

The control unit may be characterized in that the determining step is performed at every predetermined determining time interval.

In the control step, the required pressure is set to a plurality of pressure values, and the control unit drives a rail pressure regulating valve so that the pressure of the common rail sequentially reaches the plurality of pressure values. there is.

In the calculating step, the control unit may accumulate and calculate driving duty values and driving times of each rail pressure control valve until the common rail reaches the plurality of pressure values.

The set duty value may be a duty value pre-mapped according to the initial pressure and fuel temperature of the common rail.

The set time may be a time value previously mapped according to the initial pressure of the common rail and the fuel flow rate.

As a result of performing the comparison step, when only one of the driving duty value and the driving time is equal to or greater than the set duty value or the set time, the control unit re-executing the control step after a preset delay time; may be further included.

The method may further include diagnosing, by the control unit, that performance of the rail pressure control valve is normal when the driving duty value and the driving time are less than the set duty value and the set time as a result of performing the comparing step.

The method for diagnosing the performance of the rail pressure regulating valve having the structure as described above is based on two factors, the driving duty value and the operating time of the rail pressure regulating valve to follow the required pressure of the common rail, to determine the performance of the rail pressure regulating valve. , it is possible to perform more precise performance diagnosis.

In addition, it is possible to accurately diagnose the performance of the rail pressure regulating valve regardless of vehicle operation and load conditions.

1 is a block diagram showing a performance diagnosis device for a rail pressure control valve according to an embodiment of the present invention;
2 is a flowchart illustrating a method for diagnosing the performance of a rail pressure control valve according to an embodiment of the present invention.

Hereinafter, a performance diagnosis method of a rail pressure control valve according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

First, FIG. 1 is a block diagram showing a performance diagnosis device of a rail pressure control valve according to an embodiment of the present invention. As shown in FIG. 1, the performance diagnosis device of the rail pressure control valve includes a pumping injector 110 that injects fuel into the cylinder while filling the common rail 100 with fuel compressed at high pressure; a rail pressure control valve 120 controlling fuel pressure inside the common rail 100; a rail pressure sensor 130 for measuring fuel pressure inside the common rail; a temperature sensor 140 for measuring fuel temperature inside the common rail; A control unit for receiving the pumping injector 110, the rail pressure control valve 120, the rail pressure sensor 130, the temperature sensor 140 and other vehicle information and diagnosing the performance of the rail pressure control valve 120 ( 150);

The control unit 150 may receive various vehicle information, for example, an accelerator opening degree from an APS, a vehicle speed from a vehicle speed sensor, engine RPM and engine RPM change rate from an engine speed sensor, and the like, as shown in FIG. 1 , and each information The pumping injector 110 and the rail pressure regulating valve 120 are duty-controlled based on the parameters, and the performance of the rail pressure regulating valve 120 is diagnosed. The specific performance diagnosis method will be described later.

2 is a flowchart illustrating a method for diagnosing the performance of a rail pressure control valve according to an embodiment of the present invention.

1 and 2, the method for diagnosing the performance of the rail pressure regulating valve is a step in which the controller 150 controls the rail pressure regulating valve 120 so that the pressure of the common rail 100 reaches the required pressure (S210). ; After the control step (S210), the control unit cumulatively calculates the driving duty value and driving time of the rail pressure control valve 120 driven until the common rail 100 reaches the required pressure (S220); After the calculating step (S220), the controller 150 compares the driving duty value and the driving time with a predetermined set duty value and a set time (S230); And as a result of performing the comparison step (S230), when the drive duty value and the drive time are equal to or greater than the set duty value and the set time, respectively, the controller 150 diagnoses that the performance of the rail pressure control valve 120 has deteriorated. It may include; step (S240).

That is, the controller 150 measures the driving time required when driving the rail pressure regulating valve 120 to control the common rail 10 to the required pressure in order to diagnose the performance of the rail pressure regulating valve 120, The driving duty value is calculated by accumulating the duty value of the rail pressure control valve 120 (S210 and S220).

As the rail pressure regulating valve 120 is controlled to a large duty value, the closing force becomes stronger and the pressure of the common rail 100 increases.

Therefore, as the driving duty value becomes greater than the set duty value, it can be determined that the performance of the rail pressure control valve 120 deteriorates and is excessively driven to reach the required pressure. In addition, it can be determined that as the driving time is longer than the set time, the time for controlling the common rail 100 to the required pressure is delayed due to the performance degradation of the rail pressure regulating valve 120 .

That is, the present technology diagnoses the performance degradation of the rail pressure control valve 120 using the driving duty value and operating time calculated through the control step (S210) and the calculation step (S220), and the performance degradation is determined by two factors. By diagnosing, the diagnostic precision can be increased.

Meanwhile, the present technology may further include a step (S200) of determining, by the control unit 150, whether the diagnosis condition of the rail pressure control valve 120 is satisfied before the control step (S210) is performed.

Specifically, in the determining step (S200), when the controller 150 detects a failure of at least one of the rail pressure sensor 130, the temperature sensor 140, and the pumping injector 110, the rail pressure control valve If it is determined that the diagnosis condition of step 120 is not satisfied, the control step S210 may not be performed.

If the pumping injector 110 that controls the pressure of the common rail 100 is out of order, it will be impossible to diagnose the performance of the rail pressure control valve 120 because the operation of the pumping injector 110 cannot be known. In addition, when the rail pressure sensor 130 and the temperature sensor 140 fail, the performance of the rail pressure control valve 120 cannot be diagnosed because the set duty value and the set time cannot be set.

Accordingly, the controller 150 performs the control step (S210) only when the rail pressure sensor 130, the temperature sensor 140, and the pumping injector 110 are normal in terms of hardware.

In addition, in the determining step (S200), the control unit 150 determines that at least one of the accelerator opening degree, vehicle speed, common rail pressure, engine speed, required fuel amount, and engine speed change rate satisfies a set value or set condition. In this case, it may be characterized in that the control step (S210) is performed by determining that the diagnosis condition of the rail pressure control valve 120 is satisfied.

The above-described diagnosis conditions are conditions that improve the reliability of the performance diagnosis of the rail pressure control valve 120, and can be said to be a situation in which the vehicle is not greatly affected by disturbance.

For example, the control unit 150 may perform a performance diagnosis of the rail pressure control valve 120 in a coasting driving situation in which the accelerator opening is 0% and the vehicle speed is 30 km or more. In addition, when the pressure of the common rail is controlled to be maintained at a value of 450 bar or more, the engine speed is included within the set RPM range, the amount of fuel required to drive the engine is 5 mg or less, and the engine speed change rate is 100 rpm or less, the influence of disturbance is not affected. performance of the rail pressure control valve 120 can be stably diagnosed.

However, since the above-described specific limited values of specific elements are merely examples to help understanding, and may be applied variably depending on vehicles and designers, they should not be limited to specific values.

In addition, in the determination step (S200), after the control unit 150 controls the common rail 100 to the set pressure, when the difference between the actual pressure of the common rail 100 and the set pressure is less than the set difference value In this case, it may be characterized in that the control step (S210) is performed by determining that the diagnosis condition of the rail pressure regulating valve 120 is satisfied.

Here, the set pressure may be set to a pressure lower than the required pressure. If the difference from the actual pressure sensed through the pressure sensor is greater than a predetermined difference value even though the common rail 100 is controlled to the set pressure, the rail pressure is adjusted. Since the process of controlling the common rail pressure using the valve 120 and setting the set duty value and the set time becomes inaccurate, the possibility of erroneously diagnosing the performance of the rail pressure control valve 120 increases.

Therefore, in order to improve the diagnostic reliability of the rail pressure regulating valve 120, it is preferable that the control unit 150 performs the control step (S210) after confirming whether the above-described diagnosing condition of the rail pressure regulating valve is satisfied.

In addition, the control unit 150 may be characterized in that the determination step (S200) is performed at predetermined determination time intervals.

That is, by checking the performance of the rail pressure regulating valve 120 at each determination time interval, failure of the common rail system due to performance degradation of the rail pressure regulating valve 120 can be prevented, thereby improving the marketability of the vehicle. there is.

Before performing the control step (S210) in the present technology, the control unit 150 controls the duty of the pumping injector 110 and the rail pressure control valve 120 to maintain the pressure of the common rail 100 at the set pressure. It is continuously performed, but only when the ratio of dividing the additional duty correction value of each of the pumping injector 110 and the rail pressure control valve 120 driven to maintain the set pressure by the pre-mapped duty value is 0.05 or less. A control step (S210) may be performed.

Here, the pre-mapped duty value indicates the duty value of each of the pumping injector 110 and the rail pressure control valve 120 required to maintain the set pressure of the common rail 100 at normal times, and the duty correction value is the actual common rail 100 ) indicates the additional duty value caused by the difference between the pressure and the set pressure.

If the ratio exceeds 0.05, it is determined that the pumping injector 110 and the rail pressure control valve 120 are excessively corrected, and the control step (S210) may not be performed to improve the reliability of the control.

Meanwhile, in the present technology, in the control step (S210), the required pressure is set to a plurality of pressure values, and the controller 150 controls the pressure of the common rail 100 to be sequentially adjusted to the plurality of pressure values. It may be characterized in that the rail pressure regulating valve 120 is driven to reach.

For example, when a plurality of required pressures are set, such as 1500 bar, 2000 bar, 2500 bar, 2000 bar, and 1500 bar, the controller 150 operates the rail pressure control valve 120 so that the pressure of the common rail 100 sequentially reaches the required pressure. drive Of course, the above-described required pressure is only according to an embodiment and should not be limited to a specific value.

At this time, in the calculation step (S220), the control unit 150 determines the driving duty value and operation of each rail pressure control valve 120 required until the common rail 100 reaches the plurality of pressure values. It may be characterized in that the times are accumulated and calculated.

That is, the performance of the rail pressure regulating valve 120 can be diagnosed by comparing the accumulated driving duty value and operating time of the rail pressure regulating valve 120 with the set duty value and the set time. Of course, in this case, the set duty value and the set time are values obtained by adding the set duty values and the set times according to each required pressure.

Therefore, since the driving duty value and the driving time are compared by driving the rail pressure control valve 120 a plurality of times, reliability of diagnosis can be improved.

Meanwhile, the set duty value is a duty value pre-mapped according to the initial pressure of the common rail 100 and the fuel temperature, and the set time is a time pre-mapped according to the initial pressure of the common rail 100 and the fuel flow rate. It can be characterized as being a value.

The initial pressure is the pressure of the common rail 100 before driving the rail pressure control valve 120. That is, the control unit 150 stores a set duty value map based on the initial pressure, required pressure, and fuel temperature of the common rail 100, and a set time map based on the initial pressure, required pressure, and fuel flow rate of the common rail 100. this is saved

If the initial pressure is lower than the required pressure, the set duty value is mapped so that the lower the initial pressure is, the larger the set duty value is. If the initial pressure is higher than the required pressure, the higher the initial pressure is, the larger the set duty value is mapped.

In addition, as the fuel temperature is lowered, the viscosity of the fuel increases and the flow does not flow smoothly, so the set duty value is mapped to increase. The higher the fuel flow rate, the longer the setting time may be mapped.

In addition, as a result of performing the comparison step (S230) in the present technology, when only one of the drive duty value or the drive time is equal to or greater than the set duty value or the set time, the controller 150 controls the control step (S210) after a preset delay time. ) Re-executing (S250); may further include.

Here, the delay time may be set shorter than the judgment time. If the performance abnormality occurs only in one of the drive duty value and the drive time, it means that the performance degradation of the rail pressure control valve 120 has occurred. Since it cannot be determined, reliability of diagnosis can be improved by performing the control step (S210) again.

If, as a result of performing the comparison step (S230), if the drive duty value and the drive time are less than the set duty value and the set time, the controller 150 diagnoses that the performance of the rail pressure control valve 120 is normal. Step (S260); may further include.

To aid understanding, the control unit 150 may be an electronic control unit (ECU).

The method for diagnosing the performance of the rail pressure regulating valve having the structure as described above is based on two factors, the driving duty value and the operating time of the rail pressure regulating valve to follow the required pressure of the common rail, to determine the performance of the rail pressure regulating valve. , it is possible to perform more precise performance diagnosis.

In addition, it is possible to accurately diagnose the performance of the rail pressure regulating valve regardless of vehicle operation and load conditions.

Although the present invention has been shown and described in relation to specific embodiments, it is known in the art that the present invention can be variously improved and changed without departing from the technical spirit of the present invention provided by the claims below. It will be self-evident to those skilled in the art.

100: common rail 110: pumping injector
120: rail pressure control valve 130: rail pressure sensor
140: temperature sensor 150: control unit

Claims (12)

controlling the rail pressure regulating valve so that the pressure of the common rail reaches the required pressure;
After the controlling step, the control unit accumulatively calculating a driving duty value and a driving time of the rail pressure regulating valve driven until the common rail reaches a required pressure;
Comparing, by the control unit, the driving duty value and the driving time with a predetermined set duty value and a set time, respectively, after the calculating step; and
As a result of performing the comparison step, when the driving duty value and the driving time are equal to or greater than the set duty value and the set time, respectively, diagnosing, by the control unit, that the performance of the rail pressure control valve has deteriorated;
The performance diagnosis method of the rail pressure control valve, characterized in that the set duty value is a duty value pre-mapped according to the initial pressure and fuel temperature of the common rail. The method of claim 1,
The method for diagnosing the performance of the rail pressure regulating valve, further comprising: before the controlling step, the control unit determining whether a diagnosis condition of the rail pressure regulating valve is satisfied. The method of claim 2,
In the determining step, when the control unit detects a failure of at least one of a rail pressure sensor, a temperature sensor, and a pumping injector, it is determined that the diagnosis condition of the rail pressure control valve is not satisfied, and the control step is not performed. A method for diagnosing the performance of rail pressure control valves. The method of claim 2,
In the determining step, the control unit controls the rail pressure regulating valve when at least one of the accelerator opening degree, vehicle speed, common rail pressure, engine speed, required fuel amount, and engine speed change rate satisfies a set value or condition. A method for diagnosing the performance of a rail pressure regulating valve, characterized in that the control step is performed by determining that the diagnosis condition is satisfied. The method of claim 4,
In the determination step, the control unit determines that the diagnosis condition of the rail pressure control valve is satisfied when the difference between the actual pressure and the set pressure of the common rail is less than the set difference value after controlling the common rail to the set pressure. A method for diagnosing the performance of a rail pressure regulating valve, characterized in that the control step is performed by performing the control step. The method of claim 2,
The method of diagnosing the performance of a rail pressure control valve, characterized in that the controller performs the determining step at each predetermined time interval. The method of claim 1,
In the control step, the required pressure is set to a plurality of pressure values,
The control unit drives the rail pressure control valve so that the pressure of the common rail sequentially reaches the plurality of pressure values. The method of claim 7,
In the calculation step, the control unit calculates the driving duty value and driving time of each rail pressure regulating valve until the common rail reaches the plurality of pressure values by accumulating and calculating the rail pressure regulating valve performance diagnosis method. delete The method of claim 1,
The performance diagnosis method of the rail pressure control valve, characterized in that the set time is a time value pre-mapped according to the initial pressure and fuel flow rate of the common rail. The method of claim 1,
As a result of performing the comparison step, when only one of the drive duty value or the drive time is greater than the set duty value or the set time, the control unit re-executing the control step after a preset delay time; further comprising rail pressure control Valve performance diagnosis method. The method of claim 1,
As a result of performing the comparison step, when the driving duty value and the driving time are less than the set duty value and the set time, diagnosing, by the control unit, that the performance of the rail pressure control valve is normal; Performance diagnosis method.

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