Clutch disc wear compensation method

Abstract

The present application relates to a clutch disc wear compensation method including a compensation value determination operation in which a compensation value for wear of a clutch disc, which is contacted and spaced apart for power transmission and interruption, is determined, and a compensation value application operation in which the clutch disc is adjusted according to a map to which the compensation value is applied, wherein the compensation value determination operation estimates the wear of the clutch disc based on a correlation between a pressure applied to the clutch disc and an output of a motor that applies the pressure to the clutch disc and determines the compensation value, thereby preventing a reduction in transmission torque due to the wear of the clutch disc.

Description

Cross-references to related applications

[0001] This application is based on and claims priority to Korean Patent Application No. 10-2023-0171623, filed on November 27, 2024, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This application relates to a method for compensating for clutch disc wear. Background Technology

[0003] Typically, a car is driven by a power transmission system that includes a transmission, differential, etc., which transmits the power generated by the engine to the tires.

[0004] This type of vehicle can be a two-wheel drive system that drives only the front or rear wheels, or a four-wheel drive system that drives both the front and rear wheels.

[0005] Four-wheel drive offers greater driving stability than two-wheel drive and is better suited for driving on rough roads, such as in mountainous terrain. It is classified as full-time four-wheel drive and optional two-wheel / four-wheel drive.

[0006] The alternative two-wheel / four-wheel drive approach requires a power transmission system, such as a transfer case for distributing drive force to the front and rear wheels, and this power transmission system includes clutch discs that transmit and disconnect power by contacting and spacing each other.

[0007] Here, the clutch disc includes a first clutch disc that can rotate together with the first shaft and a second clutch disc that can rotate together with the second shaft. The first clutch disc and the second clutch disc press against each other and come into contact or disengage through ball bearing ramps, ball screws, etc. The ball bearing ramps, ball screws, etc. will generate axial displacement according to the rotation of the motor.

[0008] However, in the prior art, there is a problem of reduced transmitted torque due to clutch disc wear. Specifically, as the first and second clutch discs wear down through contact and disengagement, their thickness decreases over time. Furthermore, when the motor rotates at a predetermined angle to bring the first and second clutch discs into contact, the contact force between the worn first and second clutch discs is less than that between the unworn first and second clutch discs. Consequently, driving force is distributed to the front and rear wheels in a manner different from the intended distribution, leading to problems such as the vehicle being unable to extricate itself from rough terrain. Summary of the Invention

[0009] One object of this application is to provide a clutch disc wear compensation method that can prevent a reduction in transmitted torque due to clutch disc wear.

[0010] To achieve the above objectives, the disclosed clutch disc wear compensation method includes: a compensation value determination operation, in which a compensation value for clutch disc wear is determined, clutch disc contact and spacing for power transmission and interruption are determined; and a compensation value application operation, in which the clutch disc is adjusted according to a map of the applied compensation value, wherein the compensation value determination operation includes: estimating the clutch disc wear and determining the compensation value based on the correlation between the pressure applied to the clutch disc and the output of the motor that applies the pressure to the clutch disc.

[0011] The compensation value determination operation may also include wear compensation control execution operations, thereby operating the motor to press the clutch disc and monitoring the motor output and angle.

[0012] The compensation value determination operation may also include: a system condition satisfaction determination operation, which determines whether the power transmission system, including the clutch disc, meets the conditions for executing the wear compensation control execution operation; and a vehicle condition satisfaction determination operation, which determines whether the vehicle, including the power transmission system, meets the conditions for executing the wear compensation control execution operation. The wear compensation control execution operation can be executed when the system condition satisfaction determination operation determines that the power transmission system meets the conditions, and the vehicle condition satisfaction determination operation determines that the vehicle meets the conditions.

[0013] The system condition satisfaction determination operation may include: a first system condition satisfaction determination operation, which determines whether the components and input values ​​of the power transmission system are normal; a second system condition satisfaction determination operation, which determines whether the temperature of the power transmission system is within a predetermined temperature range; and a third system condition satisfaction determination operation, which determines whether there are conditions that may have caused wear on the clutch disc. Specifically, when the first system condition satisfaction determination operation determines that the components and input values ​​are normal, the second system condition satisfaction determination operation determines that the temperature is within a predetermined range, and the third system condition satisfaction determination operation determines that there are conditions that may have caused wear on the clutch disc, the system condition satisfaction determination operation can determine that the power transmission system meets the conditions for executing the wear compensation control operation.

[0014] The preset temperature range can be set from 20°C to 90°C.

[0015] Based on the amount of clutch disc usage or the vehicle's travel distance being equal to or greater than a predetermined value, the third system condition is satisfied to determine that there are conditions that cause wear to have occurred on the clutch disc.

[0016] The vehicle condition fulfillment determination operation may include: a first vehicle condition fulfillment determination operation, which determines whether the vehicle's gear is in a parked or neutral state; a second vehicle condition fulfillment determination operation, which determines whether the vehicle's ignition is off; and a third vehicle condition fulfillment determination operation, which determines whether the vehicle's CAN input is valid. Based on the first vehicle condition fulfillment determination operation determining that the gear is in a parked or neutral state, the second vehicle condition fulfillment determination operation determining that the ignition is off, and the third vehicle condition fulfillment determination operation determining that the CAN input is valid, the vehicle condition fulfillment determination operation can determine that the vehicle meets the conditions for performing wear compensation control.

[0017] Assuming the reference output is defined as the motor output measured when the motor rotates a reference angle under conditions where there is no wear on the clutch disc, the compensation value determination operation may also include a data verification operation. In the data verification operation, when the motor output measured in the wear compensation control execution operation reaches the reference output, the motor angle measured in the wear compensation control execution operation is compared with the reference angle to estimate the wear of the clutch disc and determine the wear compensation value; or in the data verification operation, when the motor angle measured in the wear compensation control execution operation reaches the reference angle, the motor output measured in the wear compensation control execution operation is compared with the reference output to estimate the wear of the clutch disc and determine the wear compensation value.

[0018] The compensation value determination operation may further include: a condition change determination operation, which determines whether at least one of the power transmission system or the vehicle does not meet the conditions for executing the wear compensation control execution operation; and a wear compensation control interruption operation, which interrupts the wear compensation control execution operation. After the execution of the wear compensation control execution operation, if the condition change determination operation determines that the power transmission system and the vehicle meet the conditions, a data verification operation may be performed; and if the condition change determination operation determines that at least one of the power transmission system or the vehicle does not meet the conditions, a wear compensation control interruption operation may be performed.

[0019] The compensation value determination operation may also include: a data update necessity determination operation, which determines whether the existing wear compensation value should be updated using the wear compensation value determined in the data verification operation; a data update operation, which updates the existing wear compensation value using the wear compensation value determined in the data verification operation when it is determined that the update is necessary; and a data retention operation, which retains the existing wear compensation value when it is determined that the update is unnecessary. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a clutch disc wear compensation method according to an embodiment of the present disclosure; Figure 2 It shows in detail Figure 1 A flowchart illustrating the process of estimating the wear level of the clutch disc and determining the compensation value in a clutch disc wear compensation method; and Figure 3 This demonstrates the application. Figure 1 A graph showing the difference between vehicles using the clutch disc wear compensation method and vehicles not using the method. Detailed Implementation

[0021] The clutch disc wear compensation method according to this disclosure will be described in detail below with reference to the accompanying drawings.

[0022] Figure 1 This is a flowchart illustrating a clutch disc wear compensation method according to an embodiment of this application. Figure 2 It shows in detail Figure 1 The flowchart illustrates the process of estimating the wear level of the clutch disc and determining the compensation value in a clutch disc wear compensation method. Figure 3 This demonstrates the application. Figure 1 A graph showing the difference between vehicles using the clutch disc wear compensation method and vehicles not using the method.

[0023] refer to Figure 1 The clutch disc wear compensation method according to an embodiment of the present disclosure may include: a compensation value determination operation S1, in which a compensation value for the wear of the clutch disc is determined, the clutch disc contacts and spaced out for power transmission and interruption; and a compensation value application operation S2, in which the clutch disc is adjusted according to a mapping of the applied compensation value.

[0024] Here, even in cases where it is difficult to provide a sensor capable of measuring the pressure applied to the clutch disc (e.g., where the clutch disc is controlled not by hydraulics but by a mechanism such as a ball screw or ball runner), the compensation value determination operation S1 can be configured to estimate the wear of the clutch disc and determine the compensation value based on the correlation between the pressure applied to the clutch disc and the output of the motor that applies the pressure to the clutch disc.

[0025] Specifically, refer to Figure 2 The compensation value determination operation S1 may include the wear compensation control execution operation S14, in which the motor is operated to press the clutch disc and the output and angle of the motor are monitored.

[0026] Assuming that the motor output measured as the motor rotates a reference angle without clutch disc wear is defined as the reference output, the compensation value determination operation S1 may further include a data verification operation S17. In the data verification operation S17, the wear of the clutch disc is estimated and the wear compensation value is determined by comparing the motor angle measured in operation S14 with the reference angle when the motor output measured in operation S14 reaches the reference output; or, in the data verification operation S17, the wear of the clutch disc is estimated and the wear compensation value is determined by comparing the motor output measured in operation S14 with the reference output when the motor angle measured in operation S14 reaches the reference angle.

[0027] Here, the correlation between the motor output and the pressure applied to the clutch disc can be estimated by one of the following: constant speed control of the motor, motor angle step control, or motor duty cycle control in the clutch disengaged position (the position without clutch reaction force).

[0028] Furthermore, the wear compensation control execution operation S14 can be configured to be executed regardless of the vehicle driver's intention, in order to improve the accuracy of clutch disc wear estimation and compensation value determination.

[0029] Specifically, the compensation value determination operation S1 may also include system condition determination operation S12 and vehicle condition determination operation S11. System condition determination operation S12 determines whether the power transmission system including the clutch disc meets the conditions for executing the wear compensation control execution operation S14, and vehicle condition determination operation S11 determines whether the vehicle including the power transmission system meets the conditions for executing operation S14. When it is determined in operation S12 that the power transmission system meets the conditions for executing operation S14, and when it is determined in operation S11 that the vehicle meets the conditions for executing operation S14, the wear compensation control execution operation S14 can be executed.

[0030] exist Figure 2 In this context, operation S11 is shown to precede operation S12; however, this disclosure is not limited thereto.

[0031] System condition determination operation S12 may include a first system condition determination sub-operation, a second system condition determination sub-operation, and a third system condition determination sub-operation. The first system condition determination sub-operation determines whether the components and input values ​​of the power transmission system are normal; the second system condition determination sub-operation determines whether the temperature of the power transmission system is within a predetermined temperature range; and the third system condition determination sub-operation determines whether clutch disc wear may have occurred. If, in the first sub-operation, the components and input values ​​are determined to be normal; in the second sub-operation, the temperature of the power transmission system is determined to be within a predetermined temperature range (e.g., 20°C to 90°C); and in the third sub-operation, clutch disc wear may have occurred (when the clutch disc usage or vehicle mileage exceeds a predetermined value), system condition determination operation S12 can be configured to determine that the power transmission system meets the conditions for executing wear compensation control operation S14. This may be desirable for improving the accuracy of the determination steps regarding operation S12. For reference, the consideration for the third system condition determination sub-operation is to prevent unnecessary execution of the determination steps.

[0032] The vehicle condition determination operation S11 may include a first vehicle condition determination sub-operation, a second vehicle condition determination sub-operation, and a third vehicle condition determination sub-operation. The first vehicle condition determination sub-operation determines whether the vehicle's gear is in a park position or neutral position, the second vehicle condition determination sub-operation determines whether the vehicle's ignition is off, and the third vehicle condition determination sub-operation determines the validity of the vehicle's CAN input. When the first sub-operation determines that the vehicle's gear is in a park position or neutral position, the second sub-operation determines that the ignition is off, and the third sub-operation determines that the CAN input is valid, the vehicle condition determination operation S11 can be configured to determine that the vehicle meets the conditions for performing the wear compensation control execution operation S14. This may be desirable for improving the accuracy of the determination steps of operation S11. For reference, the consideration for the third vehicle condition determination sub-operation is to prevent misjudgments in the first and second vehicle condition determination sub-operations. In the first vehicle condition determination sub-operation, the vehicle gear may be incorrectly determined to be in the parking position or neutral position, and in the second vehicle condition determination sub-operation, the vehicle ignition may be incorrectly determined to be off when there is an error in the vehicle's CAN input.

[0033] Meanwhile, for example, there may be situations where conditions change during the execution of the wear compensation control execution operation S14 (e.g., when the vehicle is restarted). Considering this, the compensation value determination operation S1 may also include a condition change determination operation S15 and a wear compensation control interruption operation S16. The condition change determination operation S15 determines that at least one of the power transmission system or the vehicle no longer meets the conditions for executing the wear compensation control execution operation S14, and the wear compensation control interruption operation S16 interrupts operation S14. Furthermore, after the execution of operation S14, during the execution of operation S15, if the power transmission system and the vehicle are determined to meet the conditions for executing operation S14, a data verification operation S17 can be executed; and if operation S15 determines that at least one of the power transmission system or the vehicle does not meet the conditions for executing operation S14, operation S16 can be executed.

[0034] For reference, reference numeral S13 (not shown) indicates that the wear compensation control operation is not performed. The wear compensation control operation is not performed when it is determined in the system condition determination operation S12 that the power transmission system does not meet the conditions for performing the wear compensation control operation S14, or when it is determined in the vehicle condition determination operation S11 that the vehicle does not meet the conditions for performing the operation S14.

[0035] Furthermore, in order to improve the accuracy of clutch disc wear compensation through learning, the compensation value determination operation S1 may also include: a data update necessity determination operation S18, which determines whether the existing wear compensation value should be updated using the wear compensation value determined in the data verification operation S17; a data update operation S19, which updates the existing wear compensation value using the wear compensation value determined in the operation S17 when operation S18 determines that updating is necessary; and a data retention operation S20, which retains the existing wear compensation value when operation S18 determines that updating is unnecessary.

[0036] The clutch disc wear compensation method according to this configuration may include a compensation value determination operation S1 and a compensation value application operation S2. In operation S1, the wear of the clutch disc is estimated and a compensation value is determined based on the correlation between the pressure applied to the clutch disc and the output of the motor applying that pressure, thereby preventing a reduction in transmitted torque due to clutch disc wear, such that... Figure 3 As shown, even when wear occurs on the clutch disc, the driving force is distributed to the front and rear wheels as expected, allowing the vehicle to traverse rough terrain.

Claims

1. A method for compensating for clutch disc wear, comprising: The compensation value determination operation determines a compensation value for the wear of the clutch disc, which is engaged and disengaged for power transmission and interruption. as well as A compensation value application operation is performed, in which the clutch disc is adjusted according to the mapping of the applied compensation value. The compensation value determination operation includes estimating the wear of the clutch disc and determining a compensation value based on the correlation between the pressure applied to the clutch disc and the output of the motor that applies the pressure to the clutch disc.

2. The method according to claim 1, wherein, The compensation value determination operation also includes a wear compensation control execution operation, which operates the motor to press the clutch disc and monitors the output and angle of the motor.

3. The method according to claim 2, wherein, The compensation value determination operation also includes: The system conditions are met to determine whether the power transmission system, including the clutch disc, meets the conditions for executing the wear compensation control operation; and The vehicle condition meets the determination operation, which determines whether the vehicle, including the power transmission system, meets the conditions for executing the wear compensation control execution operation. Specifically, when it is determined in the system condition satisfaction determination operation that the power transmission system meets the condition, and when it is determined in the vehicle condition satisfaction determination operation that the vehicle meets the condition, the wear compensation control execution operation is performed.

4. The method according to claim 3, wherein, The system conditions satisfying the determination operation includes: The first system condition is met, and the first system condition is met, and the determination operation determines whether the components and input values ​​of the power transmission system are normal. The second system condition satisfaction determination operation determines whether the temperature of the power transmission system is within a predetermined temperature range; and The third system condition satisfaction determination operation determines whether there are conditions that cause wear to have occurred on the clutch disc. Specifically, the system condition is satisfied when the first system condition determines that the component and the input value are normal, the second system condition is satisfied when the second system condition determines that the temperature is within a predetermined range, and the third system condition is satisfied when a condition exists that causes wear to have occurred on the clutch disc. The system conditions are met to determine the operation: the power transmission system meets the conditions for executing the wear compensation control operation.

5. The method according to claim 4, wherein, The predetermined temperature range is set to 20°C to 90°C.

6. The method according to claim 4, wherein, Based on the amount of clutch disc usage or the distance the vehicle has traveled being equal to or greater than a predetermined value, the third system condition satisfies the condition that the operation determines that wear has occurred on the clutch disc.

7. The method according to claim 3, wherein, The determination operation that the vehicle conditions are met includes: The first vehicle condition meets the determination operation, which determines whether the vehicle is in a parked or neutral state. The second vehicle condition meets the determination operation, which determines whether the vehicle's ignition is turned off; and The third vehicle condition satisfaction determination operation determines whether the vehicle's CAN input is valid. Specifically, based on the first vehicle condition satisfaction determination operation, it is determined that the gear is in the parking state or the neutral state; the second vehicle condition satisfaction determination operation is determined that the ignition is turned off; and the third vehicle condition satisfaction determination operation is determined that the CAN input is valid. The vehicle condition satisfaction determination operation determines that the vehicle meets the conditions for executing the wear compensation control execution operation.

8. The method according to claim 3, wherein, Assuming the reference output is defined as the motor output measured when the motor rotates a reference angle without wear on the clutch disc, the compensation value determination operation also includes a data verification operation. In the data verification operation, the wear of the clutch disc is estimated and the wear compensation value is determined by comparing the motor angle measured in the wear compensation control execution operation with the reference angle when the motor output measured in the wear compensation control execution operation reaches the reference output; or In the data verification operation, the wear of the clutch disc is estimated and the wear compensation value is determined by comparing the motor output measured in the wear compensation control execution operation with the reference output when the motor angle measured in the wear compensation control execution operation reaches the reference angle.

9. The method according to claim 8, wherein, The compensation value determination operation also includes: The condition change determination operation determines whether at least one of the power transmission system or the vehicle does not meet the conditions for executing the wear compensation control execution operation; and The wear compensation control interruption operation interrupts the execution of the wear compensation control. Specifically, after the wear compensation control execution operation is performed, when the condition change determination operation determines that the power transmission system and the vehicle meet the conditions, the data verification operation is performed, and when the condition change determination operation determines that at least one of the power transmission system or the vehicle does not meet the conditions, the wear compensation control interruption operation is performed.

10. The method according to claim 8, wherein, The compensation value determination operation also includes: The data update necessity determination operation determines whether the existing wear compensation value should be updated using the wear compensation value determined in the data verification operation. A data update operation, when it is determined that an update is necessary, updates the existing wear compensation value using the wear compensation value determined in the data verification operation; and The data retention operation preserves the existing wear compensation value when it is determined that an update is unnecessary.

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