KR102626406B1 - Hydraulic system checking method and apparatus of all wheel drive system - Google Patents

Abstract

The present invention relates to a technology for detecting a shortage of oil flow by determining whether the target pressure is generated and the time required to generate the target pressure through a hydraulic test. In the present invention, when the ignition of the vehicle is turned on, the Applying a drive command to the pump to generate a target pressure; determining whether the target pressure is generated; and limiting the maximum value of the pump drive command required to generate the target pressure when the target pressure is not generated. A method and device for checking a hydraulic system of an AWD system are introduced.

Description

Hydraulic system inspection method and device of AWD system {HYDRAULIC SYSTEM CHECKING METHOD AND APPARATUS OF ALL WHEEL DRIVE SYSTEM}

The present invention relates to a hydraulic system inspection method and device for an AWD system that detects a shortage of oil flow by determining whether a target pressure is generated and the time required to generate the target pressure through a hydraulic test.

The vehicle's All Wheel Drive (AWD) system is a system in which both the front and rear axles are driven, with a switchable all-wheel drive system that drives only one axle at all times and transmits driving force to the remaining axles only when necessary, and all wheels It is classified into permanent all-wheel drive, which is always driven by the driving force of the engine.

In this AWD system, the control command value is determined according to information reflecting the driving state of the vehicle, and the driving force transmitted to the front and rear wheels is distributed according to the determined control command value.

However, if the oil flow rate is insufficient in the hydraulic system that operates the AWD system, the command value and output value are different, which limits maximum pressure generation, which can cause overload in pressure control.

Of course, this can be easily solved by installing a sensor capable of detecting the oil flow rate, but if there is no sensor capable of detecting the oil flow rate in the hydraulic system, the size of the output pressure that changes depending on the oil flow rate cannot be properly detected. There is.

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

KR 10-2005-0091717 A

The present invention was developed to solve the problems described above, and is a hydraulic system inspection of an AWD system that detects a shortage of oil flow by determining whether the target pressure is generated and the time required to generate the target pressure through a hydraulic test. To provide a method and device.

The configuration of the present invention for achieving the above object includes the steps of a controller, when the ignition of the vehicle is turned on, applying a drive command to the pump to generate a target pressure for a hydraulic test; A controller determining whether to generate the target pressure; And when the controller fails to generate the target pressure, limiting the maximum value of the pump drive command required to generate the target pressure.

In the step of limiting the maximum value of the drive command, a warning may be given that the oil flow rate is insufficient.

The target pressure for the hydraulic test is set at multiple target pressures with different target pressures; Determine whether the target pressure is generated for each target pressure; If the target pressure is not generated, the maximum value of the pump drive command required to generate the target pressure may be limited.

The target pressure is set to a first target pressure, which is the maximum pressure that can be generated by the motor driving the pump, and a plurality of n-th target pressures smaller than the first target pressure, where the first target pressure and the n-th target pressure may be greater than the pressure required to reach the clutch kisspoint.

When the target pressure is generated, determining whether the reaction time required to generate the target pressure is longer than the set time; It may include a step of warning that the oil flow rate is insufficient when the reaction time is longer than the set time.

If the reaction time is longer than the set time, the hydraulic test history after the ignition on is determined, and if there is a hydraulic test history, a warning that the oil flow rate is insufficient can be provided.

If the reaction time is longer than the set time, the hydraulic test history after the ignition on is determined, and if there is no hydraulic test history, the hydraulic test can be re-performed by increasing the output of the motor driving the pump.

The reaction time is set as the time taken to reach the target pressure at the kiss point of the clutch when driving the pump for the hydraulic test; The set time compared to the reaction time may be determined according to the target pressure.

The configuration of the hydraulic system inspection device of the present invention includes: a control unit that applies a drive command to the pump to generate a target pressure for a hydraulic test when the ignition of the vehicle is turned on; a determination unit that determines whether the target pressure is generated; and a control unit that limits the maximum value of the pump drive command required to generate the target pressure when the target pressure is not generated.

Through the above-described problem solving means, the present invention provides a solution to the oil pressure when driving the pump so that the oil pressure reaches a specific target pressure, when the oil pressure does not reach the target pressure or when the reaction time to reach the target pressure is significantly delayed. It is determined that the oil flow rate in the tank is insufficient.

Therefore, by limiting the drive command value of the pump from exceeding the drive command value required to generate the target pressure, there is an effect of preventing overload of the motor and safely protecting the hydraulic system.

1 is a diagram illustrating the inspection flow of the hydraulic system of the AWD system according to the present invention.
Figure 2 is a diagram illustrating the hydraulic system inspection device of the AWD system according to the present invention.
Figure 3 is a time graph illustrating the target pressure and actual output pressure according to the pump drive command during the hydraulic test process according to the present invention.

A preferred embodiment of the present invention will be described in detail with the accompanying drawings as follows.

The method for checking the hydraulic system of the AWD system of the present invention is based on the principle that if the oil flow rate in the oil tank decreases when hydraulic pressure is generated by the pump 3, it is difficult to generate a set pressure, and a time delay occurs even if the same pressure is generated. As used, the present invention includes the steps of applying a drive command to the pump 3, checking whether the target pressure is generated, and limiting the maximum value of the drive command.

Accordingly, looking at the control configuration in detail with reference to FIG. 1, first, in the drive command application step, the controller (CLR) sends a drive command to the pump 3 to generate a target pressure for a hydraulic test when the ignition of the vehicle is turned on. authorizes.

And, in the target pressure confirmation step, the controller (CLR) determines whether the target pressure is generated.

Next, in the drive command maximum value limiting step, when the controller (CLR) fails to generate the target pressure, it limits the maximum value of the pump 3 drive command required to generate the target pressure.

That is, according to the above configuration, when driving the pump 3 so that the oil pressure reaches a specific target pressure, if the oil pressure does not reach the target pressure, it is determined that the oil flow rate in the oil tank is insufficient, and thus the pump The drive command value in (3) is limited to not exceed the drive command value required to generate the target pressure.

Therefore, overload of the motor (1) driving the pump (3) is prevented and the hydraulic system is safely protected.

In addition, in the step of limiting the maximum value of the drive command, control can be made to not only limit the maximum value of the drive command of the pump 3 but also warn the driver of the insufficient oil flow rate. In other words, it can be configured to display insufficient oil flow on the vehicle's cluster or provide a voice warning.

In addition, in the case of the present invention, as shown in FIG. 3, the target pressure for the hydraulic test can be set in multiple ways by varying the target pressure.

Then, it is determined whether the target pressure is generated for each target pressure.

Accordingly, when the target pressure is not generated, the maximum value of the pump 3 drive command required to generate the target pressure is limited.

At this time, the target pressure is set to a first target pressure, which is the maximum pressure that the driving motor (1) of the pump (3) can generate, and a plurality of nth target pressures smaller than the first target pressure, where the first target pressure The pressure and nth target pressure can be set to a pressure greater than the pressure required to reach the clutch kiss point. Here, the kiss point may be a point in time when the clutch 5 is contacted during the process of engaging the clutch 5 and the transmission torque of the clutch 5 begins to be generated.

For example, when three target pressures are set, the first target pressure can be set to the maximum pressure that the driving motor (1) of the pump (3) can generate, and the second target pressure is approximately 1 of the first target pressure. It can be set to a pressure equivalent to about /2, and the third target pressure can be set to a pressure equivalent to approximately 1/4 of the first target pressure. At this time, the third target pressure may be a pressure generally used to control the clutch 5.

Meanwhile, in the present invention, when it is determined that the target pressure is generated as a result of determining whether the target pressure is generated, determining whether the reaction time required to generate the target pressure is more than the set time, and the step of determining whether the reaction time is more than the set time It can be configured to further include a step of warning that the oil flow rate is insufficient.

In other words, even if a specific oil pressure can be generated when generating a specific hydraulic pressure through the pump 3, if the oil flow rate is relatively insufficient, the time required to generate the oil pressure may be delayed.

Therefore, when the pump 3 is driven, the oil pressure reaches the target pressure, but if the reaction time required to generate the target pressure becomes long, it can be determined that the oil flow rate in the oil tank is insufficient. However, in this case, it is determined that the generation of the target pressure is at least possible, so the maximum driving command value of the pump 3 is not limited and the driver can only be warned of a situation in which the oil flow rate is insufficient.

In addition, as another example, when the reaction time is longer than the set time, the hydraulic test history after the ignition on is determined, and if there is a hydraulic test history, a warning that the oil flow rate is insufficient can be provided.

On the other hand, as a result of determining the hydraulic test history after the ignition on, if there is no hydraulic test history, the hydraulic test can be re-performed by increasing the output of the motor (1) driving the pump (3).

In other words, when it is determined that the reaction time is delayed, it does not immediately warn of a situation where the oil flow is insufficient, but further determines whether a hydraulic test has been previously performed and warns of the insufficient oil flow, or performs the hydraulic test again. You can control it.

For example, if there is no history of performing a hydraulic test while the reaction time is delayed, the hydraulic test is performed again, and if there is already a history of performing a hydraulic test, a warning is issued regarding insufficient oil flow rate.

At this time, the reaction time is set to the time taken to reach the target pressure at the kiss point of the clutch 5 when driving the pump 3 for the hydraulic test.

Additionally, the set time compared to the reaction time may be determined according to the target pressure.

In other words, the set time is a standard time for determining how appropriate the time required to increase the hydraulic pressure to the target pressure is. As the target pressure increases, the reaction time also increases, so the set time depends on the size of the target pressure. will also change together.

Meanwhile, the hydraulic system inspection device of the AWD system according to the present invention is largely comprised of an operation unit 9, a determination unit 11, and an adjustment unit 13.

Referring to FIG. 2 , the control unit 9 applies a drive command to the pump 3 to generate a target pressure for a hydraulic test when the ignition of the vehicle is turned on.

The determination unit 11 determines whether the target pressure is generated.

In the case where the target pressure is not generated, the control unit 13 serves to limit the maximum value of the pump 3 drive command required to generate the target pressure.

However, the functions of the manipulation unit 9, determination unit 11, and control unit 13 may be configured to be implemented through a controller (CLR).

That is, when the ignition of the vehicle is turned on, the controller (CLR) applies a drive command to the pump 3 to generate a target pressure for a hydraulic test, determines whether the target pressure is generated, and sets the target pressure. If it is not generated, it serves to limit the maximum value of the pump 3 drive command required to generate the target pressure.

Hereinafter, the flow of the hydraulic system inspection process according to the present invention will be described by way of example with reference to FIG. 1.

First, determine whether the ignition is in the on state through the vehicle's ignition switch (S10).

When it is determined that the ignition is on, a hydraulic signal is received and a hydraulic test is performed (S20).

To explain the process of the hydraulic test by way of example, first, three pressures, the maximum pressure, the intermediate pressure, and the general pressure, are set as target pressures.

Then, the operation of the motor (1) is first controlled to drive the pump (3) to generate pressure that reaches the key point of the clutch (5), and then the pump (3) is controlled to generate the maximum pressure. Control the drive.

Subsequently, the operation of the motor 1 is controlled secondarily to drive the pump 3 to generate pressure that reaches the key point of the clutch 5, and then the operation of the pump 3 is controlled to generate intermediate pressure. Control the drive.

Then, the operation of the motor (1) is controlled in three ways to drive the pump (3) to generate pressure that reaches the key point of the clutch (5), and then the pump (3) is controlled to generate general pressure. Control the drive.

Next, after controlling to generate pressure that reaches the kissing point of the clutch 5, the pressure is removed, and the above first, second, and third tests are repeated a predetermined number of times.

Accordingly, the actual output pressure tested for each target pressure is averaged, and the average value is compared with the corresponding target pressure.

That is, in the above hydraulic test process, it is determined whether the maximum pressure, intermediate pressure, and general pressure are normally generated by measuring the actual pressure using the hydraulic sensor 7 (S30).

If all pressures are formed normally as a result of the judgment in step S30, the reaction time required to generate the maximum pressure, intermediate pressure, and general pressure is compared with the set time (S40), and as a result of the comparison in step S40, the reaction time is the set time. If it is within the range, the oil flow rate is determined to be sufficient and the hydraulic system is diagnosed as normal (S50).

On the other hand, as a result of the judgment in step S30, if the maximum pressure, intermediate pressure, and general pressure are not formed normally, the maximum value of the pump (3) drive command applied to generate the corresponding pressure is limited, and the driver is controlled through the cluster, etc. Warns the user of an abnormal condition in the hydraulic system with insufficient oil flow (S60).

Meanwhile, as a result of the comparison in step S40, if the reaction time is longer than the set time, it is determined whether there is a history of re-performing the hydraulic test after ignition on (S70).

As a result of S70's judgment, if there is a history of re-performing the hydraulic test, the driver is warned of an abnormal condition of the hydraulic system with insufficient oil flow through the cluster, etc. (S80).

On the other hand, as a result of the judgment at S70, if there is no history of re-performing the hydraulic test, the output is increased by increasing the P gain of the motor 1 (S90), and the hydraulic test is re-performed (S20).

As described above, in the present invention, as a result of performing a hydraulic test in which the pump 3 is driven so that the oil pressure reaches a specific target pressure, the oil pressure does not reach the target pressure, or the reaction time to reach the target pressure is long. If there is a delay, it is determined that the oil flow rate in the oil tank is insufficient.

Accordingly, by limiting the drive command value of the pump 3 from exceeding the drive command value necessary to generate the target pressure, overload of the motor 1 is prevented and the hydraulic system is safely protected.

Meanwhile, although the present invention has been described in detail only with respect to the above-mentioned specific examples, it is clear to those skilled in the art that various changes and modifications are possible within the technical scope of the present invention, and it is natural that such changes and modifications fall within the scope of the appended patent claims. .

1: motor
3: pump
5: Clutch
7: Hydraulic sensor
9: Control panel
11: Judgment unit
13: control unit
CLR: Controller

Claims (9)

A step of the controller applying a drive command to the pump to generate a target pressure for a hydraulic test when the ignition of the vehicle is turned on;
A controller determining whether to generate the target pressure; and
Including, when the controller fails to generate the target pressure, limiting the maximum value of the pump drive command required to generate the target pressure,
A method for checking the hydraulic system of an AWD system, characterized in that it warns that the oil flow rate is insufficient in the step of limiting the maximum value of the drive command. delete A step of the controller applying a drive command to the pump to generate a target pressure for a hydraulic test when the ignition of the vehicle is turned on;
A controller determining whether to generate the target pressure; and
Including, when the controller fails to generate the target pressure, limiting the maximum value of the pump drive command required to generate the target pressure,
The target pressure for the hydraulic test is set at multiple target pressures with different target pressures;
Determine whether the target pressure is generated for each target pressure;
A method of checking the hydraulic system of an AWD system, characterized in that when the target pressure is not generated, the maximum value of the pump drive command required to generate the target pressure is limited. In claim 3,
The target pressure is,
Set to a first target pressure, which is the maximum pressure that can be generated by the motor driving the pump, and a plurality of n-th target pressures smaller than the first target pressure, where the first target pressure and n-th target pressure are located at the clutch kiss point. A method of checking the hydraulic system of an AWD system, characterized in that the pressure is greater than the pressure required to reach. A step of the controller applying a drive command to the pump to generate a target pressure for a hydraulic test when the ignition of the vehicle is turned on;
A controller determining whether to generate the target pressure; and
Including, when the controller fails to generate the target pressure, limiting the maximum value of the pump drive command required to generate the target pressure,
When the target pressure is generated, determining whether the reaction time required to generate the target pressure is longer than the set time;
A method for checking a hydraulic system of an AWD system, comprising: warning that the oil flow rate is insufficient when the reaction time is longer than the set time. In claim 5,
When the reaction time is more than the set time, the hydraulic test history after the ignition on is determined, and if there is a hydraulic test history, a hydraulic system inspection method of the AWD system is characterized by warning that the oil flow rate is insufficient. In claim 5,
If the reaction time is more than the set time, the hydraulic test history after the ignition on is determined, and if there is no hydraulic test history, the output of the motor driving the pump is increased and the hydraulic test is re-performed. How to check hydraulic system. In claim 5,
The reaction time is set as the time taken to reach the target pressure at the kiss point of the clutch when driving the pump for the hydraulic test;
A hydraulic system inspection method for an AWD system, characterized in that the set time compared to the reaction time is determined according to the target pressure. A control unit that applies a drive command to the pump to generate a target pressure for a hydraulic test when the vehicle's ignition is turned on;
a determination unit that determines whether the target pressure is generated; and
A control unit that limits the maximum value of the pump drive command required to generate the target pressure when the target pressure is not generated,
A hydraulic system inspection device for an AWD system, characterized in that it limits the maximum value of the drive command and warns of insufficient oil flow.

Images