KR20120062259A - System for protection friction element of hybrid vehicle and method thereof - Google Patents

Abstract

PURPOSE: An apparatus and a method for protecting the frictional elements of a hybrid vehicle are provided to improve power performance by implementing the mode conversion of a two-mode hybrid vehicle based on sufficient slipping. CONSTITUTION: An apparatus for protecting the frictional elements of a hybrid vehicle includes an engine, a first motor, a second motor, frictional elements, and a controller. The first motor operates based on idle stop and go. The second motor generates driving torque. The frictional elements transfer power or generate counter force. The controller detects the output torque and the speed of an engine, the torque of the first motor, and the torque of the second motor(S203). The controller calculates the corresponding torque and the relative speed of frictional elements(S204). The controller calculates the heating values of the frictional elements(S205). The slipping amounts of the frictional elements are limited based on the heating values of the frictional elements(S207).

Description

Friction element protection device and method of hybrid vehicle {SYSTEM FOR PROTECTION FRICTION ELEMENT OF HYBRID VEHICLE AND METHOD THEREOF}

The present invention relates to a hybrid vehicle, and more particularly, to calculate the calorific value of each friction element configured in the transmission when the mode switching of the two-mode hybrid vehicle exceeds the set heat amount of the hybrid vehicle for limiting control of the slip amount of each friction element A friction element protection device and method.

The demand for eco-friendly cars is increasing due to the demand for improved fuel economy and the tightening of emission regulations for vehicles. As a realistic alternative, hybrid cars are being provided.

The hybrid vehicle may have a narrow meaning and may be distinguished from a fuel cell vehicle and an electric vehicle. In the present specification, the hybrid vehicle encompasses a pure electric vehicle and a fuel cell vehicle, and includes one or more batteries, and energy stored in the battery Refers to a vehicle used as a driving force of the vehicle.

Hybrid cars have engines and motors as their power sources, and the engines and motors can be used depending on driving conditions to provide fuel efficiency and reduced emissions.

Hybrid cars offer improved fuel economy and a comfortable ride, depending on how the engine and motor operate in harmony while driving with two power sources consisting of an engine and a motor.

The transmission applied to the two-mode hybrid vehicle is not equipped with a torque converter and a clutch that regulates power unlike the transmission applied to a general vehicle.

Therefore, the clutch and the brake which are the friction elements configured in the transmission when the mode is switched to slip, and generates heat by friction according to the slip.

In particular, excessive slip may occur during the mode switching process, and heat exceeding the allowable capacity of the clutch and brake, which is the friction element, may be used to burn the disc, thereby reducing the friction coefficient of the disc and driving the vehicle. It causes problems that make sex worse.

The present invention has been proposed to solve the above problems, and an object of the present invention is to calculate the amount of heat generated by friction elements configured in a transmission when switching modes of a two-mode hybrid vehicle, and to calculate the amount of slips by friction elements when the heat amount exceeds a set heat amount. By limiting control, it is to provide burnout prevention of the friction elements constituting the transmission.

According to a feature of the invention, the engine; A first motor operated by an ISG; A second motor generating drive torque; It includes a number of friction elements that transmit power or generate reaction force,

The friction element of the hybrid vehicle including a controller that prevents the burnout of the disc by limiting the slip amount of the friction element when the friction element exceeding the set reference heat is detected by calculating the calorific value of each friction element when the mode change is executed. Protection is provided.

The controller detects the engine output torque and speed, the torques of the first motor and the second motor when the mode change is detected, calculates the charge torque and relative speed for each friction element, and calculates the charge torque and relative speed for each friction element and slip. Time can be used to calculate the calorific value of each friction element.

In addition, according to another feature of the invention, the process of determining whether the mode switching is carried out in the running state; Calculating mode torque and relative speed for each friction element by detecting engine torque and speed, torque of the first motor and the second motor when the mode switching is performed; Calculating calorific value for each friction element using the calculated torque, relative speed, and slip time calculated for the friction element; Friction of the hybrid vehicle comprising the step of blocking excessive slip by controlling the slip amount of the friction element when the friction element exceeding the reference heat amount is detected by comparing the calculated calorific value for each friction element and the set reference heat amount Element protection is provided.

Thus, according to the embodiment of the present invention, sufficient slip is available when switching modes in a two-mode hybrid vehicle, thereby providing an improvement in power performance.

In addition, by preventing excessive slippage of the friction elements constituting the transmission during mode switching, burnout of the friction elements can be prevented in advance.

1 is a view schematically showing a friction element protection device of a hybrid vehicle according to an embodiment of the present invention.
2 is a flowchart illustrating a friction element protection procedure of a hybrid vehicle according to an embodiment of the present invention.

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

The present invention can be embodied in various different forms, and thus the present invention is not limited to the embodiments described herein.

1 is a view schematically showing a friction element protection device of a hybrid vehicle according to an embodiment of the present invention.

Referring to FIG. 1, the present invention includes an engine 10, a first motor 21, a second motor 23, a planetary gear 30, and a controller 40.

The output of the engine 10 is directly connected to the first carrier 32 of the planetary gear 30 constituting the transmission, and is connected to the second motor 23 and the second sun gear 43 through the second clutch CL2. Connected.

The input of the second sun gear 34 is determined by the sum of the torque of the engine 10 and the second motor 23 or the torque of only the second motor 23 according to whether the second clutch CL2 is operated.

The first motor 21 is operated when the motor mode (EV) driven only by driving the second motor 23 is switched to the hybrid mode (HEV) or when the charge of the battery is required to start the engine 10, When the hybrid mode HEV is switched to the motor mode EV or when the full charge of the battery is detected as the output torque of the engine 10, the engine 10 is operated as an ISG (Idle Stop and Go) for turning off the start of the engine 10.

The first motor 21 is connected to the first brake BK1 and the first sun gear 31.

The second motor 23 outputs a drive speed and torque that follows the required torque of the driver under the control of the controller 40 as a drive motor, and transmits the drive speed and torque to the output shaft through the second sun gear 34 and the second carrier 35. do.

The output torque of the second motor 23 may be summed with the output torque of the engine 10 according to the operation of the second clutch CL2 to be output through the second sun gear 34 and the second carrier 35. .

The second motor 23 may be operated as a generator when the output of the engine 10 input through the second clutch CL2 is sufficient to charge a battery (not shown).

The first ring gear 33 of the planetary gear 30 is connected to the second carrier 35 to which the output shaft (Output) is connected, and the first carrier 32 is connected to the second brake through the first clutch CL1. BK2) and the second ring gear 36.

The controller 40 determines whether the mode change occurs in the running state, and when the mode change occurs, detects the output torque and the speed (speed) of the engine 10, and the first motor 21 and the second motor 23. To detect the torque.

The calculated torque and relative speed for each friction element including the first clutch CL1, the second clutch CL2, the first brake BK1, and the second brake BK2 are calculated, and the charge for each friction element is calculated. Calculate the calorific value of each friction element by using torque, relative speed and slip time.

Subsequently, it is determined whether the calculated calorific value for each friction element exceeds the set reference calorie value, thereby limiting the slip amount for the friction element exceeding the reference calorie value to prevent the calorific value of the friction element from exceeding the calorific value.

The reference heat amount may be set based on a temperature at which the disc of the friction element can be burned out.

Referring to the operation of the present invention including the function as described above are as follows.

2 is a flowchart illustrating a friction element protection procedure of a hybrid vehicle according to an embodiment of the present invention.

In the state in which the two-mode hybrid vehicle to which the present invention is applied is operated (S201), the controller 40 determines whether mode switching is performed (S202).

In the determination of S202, the controller 40 executes normal control in a state in which the current condition is maintained when the mode change is not detected (S208). When the execution of the mode change is detected, the output torque and the speed of the engine 10 ( The number of revolutions) and the torque of the first motor 21 and the second motor 23 are detected (S203).

Thereafter, the first clutch CL1, the second clutch CL2, and the first brake BK1 using the output torque and the speed of the engine 10 and the torques of the first motor 21 and the second motor 23. And the torque and the relative speed for each friction element composed of the second brake (BK2) can be calculated as shown in Table 1 below (S204).

When the charge torque and the relative speed for each friction element are calculated as described above, the calorific value of each friction element, that is, the slip energy, is calculated by applying the following equation 1 using the charge torque, the relative speed and the slip time for each friction element ( S205).

Where E: clutch slip energy (KJ), μ: friction coefficient of friction material, Fn: load acting on clutch pack (kgf), n: number of friction surfaces, Rm: effective radius of disk (m), ΔW : Relative velocity (rad / sec) of friction surface during shifting, ts: It means the time of friction.

Then, it is determined whether there is a friction element exceeding the set reference heat amount among the calculated calorific values for each friction element (S206), and if there is no friction element exceeding the reference heat amount, normal control is maintained under the current condition (S208). If there is a friction element exceeding the reference calorific value, the slip ratio of the friction element is controlled to prevent excessive slip (S207).

Accordingly, no burnout of the disk due to excessive slip of the friction elements is generated, thereby providing durability and reliability of the transmission.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, , Additions, deletions, and so on, other embodiments may be easily suggested, but this is also included in the spirit of the present invention.

10: engine 21: first motor
22: second motor 30: planetary gear
40: controller

Claims (5)

engine;
A first motor operated by an ISG;
A second motor generating drive torque;
A plurality of friction elements for transmitting power or generating reaction forces;
Including;
A controller configured to calculate the calorific value of each friction element when the mode switching is executed, and to limit the slip amount of the friction element to prevent the burnout of the disk when a friction element exceeding the set reference heat amount is detected;
Friction element protection device of a hybrid vehicle comprising a. The method of claim 1,
The controller detects the engine output torque and speed, the torques of the first motor and the second motor when the mode change is detected, calculates the charge torque and relative speed for each friction element, and calculates the charge torque and relative speed for each friction element and slip. Friction element protection device for a hybrid vehicle, characterized in that for calculating the calorific value for each friction element using the time. The method of claim 1,
The controller is for the calorific value of each friction element,

[E: clutch calorific value (KJ), μ: friction coefficient of friction material, Fn: load acting on clutch pack (kgf), n: number of friction surfaces, Rm: effective radius of disk (m), △ W: shift Relative Velocity of Friction Surface (rad / sec), ts: Friction Time]
Friction element protection device of a hybrid vehicle, characterized in that calculated by. Determining whether mode switching is performed in a driving state;
Calculating mode torque and relative speed for each friction element by detecting engine torque and speed, torque of the first motor and the second motor when the mode switching is performed;
Calculating calorific value for each friction element using the calculated torque, relative speed, and slip time calculated for the friction element;
Comparing the calculated calorific value for each friction element with a set reference calorific value and detecting a friction element exceeding a reference calorific value to limit the slip amount of the friction element so as to prevent excessive slip from occurring;
Friction element protection method of a hybrid vehicle comprising a. The method of claim 4, wherein
The calorific value of each friction element is based on the calorific value of each friction element.

[E: clutch calorific value (KJ), μ: friction coefficient of friction material, Fn: load acting on clutch pack (kgf), n: number of friction surfaces, Rm: effective radius of disk (m), △ W: shift Relative Velocity of Friction Surface (rad / sec), ts: Friction Time]
Friction element protection device for a hybrid vehicle, characterized in that the calculation. The friction element protection method of a hybrid vehicle, characterized in that calculated by applying the following equation (3).

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