KR20160049715A - Clutch Control Method of Electric 4 Wheel Drive System - Google Patents

Abstract

An electric four wheel drive system clutch control method of the present invention is characterized in that a vehicle speed, which is detected in a state of D/C off of a disconnector (1) where a sleeve (6) does not engage with an input shaft (9-1), is evaluated; a state of the disconnector (1) is converted into D/C ready by an electric four wheel drive system for engaging the sleeve (6) with the input shaft (9-1), and simultaneously, a state of an electric four wheel drive motor is converted into electric four wheel drive motor synchronization for synchronizing with a wheel speed of left and right rear wheels; and when a D/C on signal is applied, the state of the disconnector (1) is D/C on by engaging the sleeve (6) with the input shaft (9-1), and simultaneously, the electric four wheel drive motor is operated in a state of electric four wheel drive motor on for synchronizing with a wheel speed of front and rear wheels. Accordingly, the disconnector (1) may rapidly be coupled by prior compression of first and second springs (3-1, 3-2) carried out in a state of D/C off of the disconnector (1) when D/C on is instructed, and especially, since electric four wheel drive motor RPM synchronization is prepared by the prior compression of the first and second springs (3-1, 3-2), responsibility may be improved by omitting the spring compression and the electric four wheel drive motor RPM synchronization when D/C on is instructed.

Description

[0001] Clutch Control Method of Electric 4-Wheel Drive System [

More particularly, the present invention relates to an e-4WD system clutch control method that greatly enhances engagement command response in a ready state using a high engagement probability in a disconnection off state in which a motor and a wheel are connected and disconnected .

In general, the electric four-wheel drive system (e-4WD system) is a system in which 4WD function and HEV (hybrid electric vehicle) function can be obtained simultaneously by driving the rear wheel of a vehicle having a front engine front wheel drive And controls the engine and the motor of the hybrid vehicle by utilizing a continuously variable transmission or a multi-stage transmission.

To this end, the e-4WD system includes a dog clutch type disconnector, generates a D / C on signal at the time of disconnection, synchronizes the speed of the e-4WD motor with the speed of the wheel, Actuator (motor) is activated.

In this way, the disconnector is turned on / off to connect or disconnect the e-4WD motor and the wheel, and in particular by disconnecting the drive element of the e-4WD motor and the driven element of the rear wheel, The driving force is not transmitted to the motor by free-wheeling, and damage to the motor by the driving force of the driven element can be prevented.

Korean Patent Publication No. 10-2014-0086685 (Jul. 08, 2014)

However, the disconnector requires a spring compression time by the actuator operation when applying a fastening signal, so that the spring compression time is required in addition to the e-4WD motor speed and the wheel synchronization time until the engagement is completed.

As a result, the disconnection has a fundamental limitation that it requires a longer engagement time than the multi-plate clutch.

The present invention takes the above-mentioned points into consideration and proactively compresses the spring based on signals such as vehicle speed, wheel speed, steering angle, and e-4WD motor rpm in the D / C OFF state of the disconnector, On-command is fastened, and e-4WD motor rpm synchronization preparation is done by dictionary compression of dictionary, so spring response and D-C ON command are improved and responsiveness is improved by omission of e-4WD motor rpm synchronization. And to provide a method for controlling the clutches of the clutches.

In order to accomplish the above object, the present invention provides an e-4WD system clutch control method comprising the steps of: (A) detecting a vehicle speed detected in a D / C OFF state of a disconnector whose sleeve is not engaged with an input shaft, D / C READY < / RTI > (B) The e-4WD system converts e-4WD motor to e-4WD motor synchronization to synchronize the e-4WD motor with the wheel of the left and right rear wheels. Conversion; (C) When the D / C ON signal is applied by the e-4WD system at the time of vehicle speed detection, the disconnector is put into the D / C ON state by the sleeve being engaged with the input shaft, And the e-4WD motor is turned ON to be synchronized with the wheel.

(B-1a) a control command for an actuator to move to a range that does not move the shift fork coupled with the sleeve is generated; (b-2a) a need for the actuator by the control command The current value is calculated, and (b-3a) the actuator is operated within a range in which the shift fork is not moved. The actuation of the actuator compresses the length of the first spring among the first and second springs provided on both sides of the actuator, thereby reducing the length before compression.

The e-4WD motor synchronization switching is performed by converting the wheel speed into a wheel e-4WD motor RPM such as RPM (Revolution per Minute) of the e-4WD motor, (b-2b) And the target RPM is calculated.

(C-1a) a control command for an actuator to move to a range for moving a shift fork coupled with the sleeve is generated, (c-2a) a required current of the actuator by the control command (C-3a), the actuator is operated within a range for moving the shift fork. The operation of the actuator compresses the length of the second spring among the first and second springs provided on both sides of the actuator, thereby reducing the length before compression.

4WD inverter is controlled by the e-4WD system, and the e-4WD inverter controls the e-4WD motor RPM by an allowable RPM error (c-2b) Is reached.

The D / C ON signal is applied when the vehicle speed is less than 120 KPH, and the D / C OFF signal is applied when the vehicle speed is 120 KPH or more.

In the present invention, spring compression for D / C ON and synchronization of the e-4WD motor rpm are performed in advance in the D / C OFF state of the disconnector, thereby significantly increasing the disconnection speed.

Further, the present invention has the effect of enabling driving force assisting by the e-4WD system, 4WD performance, regenerative braking performance, and the like by performing rapid disconnection.

2 is a D / C OFF state of a disconnector controlled by an e-4WD system according to an embodiment of the present invention. FIG. 3 is a block diagram of the e-4WD system clutch control method according to the present invention. FIG. 4 is a D / C ON state of a disconnector controlled by an e-4WD system according to the present invention, and FIG. 4 is a D / C ON state of a disconnector controlled by an e-4WD system.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the present invention. The present invention is not limited to these embodiments.

Fig. 1 shows a method of controlling an e-4WD system clutch according to the present embodiment. The clutch control described below is assumed to be implemented through the e-4WD system.

When the e-4WD system is operated as in S10, the e-4WD system enters the D / C READY mode in the D / C OFF state of the disconnector as in S20.

The D / C OFF state of the disconnector is illustrated in FIG. As shown in the figure, the disconnector 1 comprises an actuator 2 controlled by an e-4WD system, a pair of first and second springs 3-1 and 3-2 compressively deformed by the movement of the actuator 2, The shift fork 5 moved by the movement of the actuator 2 and the sleeve 6 moved together with the shift fork 5 are connected to the input shaft 9-1 via the sleeve 6, And a hub 7 for rotating the hub 7. Therefore, in the D / C OFF state, the actuators 2 are not operated and the lengths of the first and second springs 3-1 and 3-2 are the pre-compression lengths A and B, respectively, and the shift fork 5 and the sleeve 6 are located on the hub 7 side. Here, the disconnector 1 is typically a disconnector that is configured with an e-4WD system. Therefore, the actuator 2, the first and second springs 3-1 and 3-2, the shift fork 5, the sleeve 6, the hub 7, the input shaft 9-1, the output shaft 9-2 ) Or unexplained operations and components are typically the same as disconnectors that work with the e-4WD system.

S30 is a step of determining a condition for entry into the D / C READY mode. To this end, the e-4WD system determines whether or not the vehicle enters the D / C READY mode with the detected vehicle speed, and applies the following equation.

Vdt (detected vehicle speed) Vth (D / C READY vehicle speed) - Equation 1, where "?" Means that Vdt is equal to or smaller than Vth. Therefore, when Vth is greater than or equal to Vdt, the D / C READY mode entry is made. In the present embodiment, the D / C READY vehicle speed is less than 120 KPH and can not exceed 120 KPH because the D / C ON signal is applied at 120 KPH or less while the D / C OFF signal is applied at 120 KPH or more .

When the D / C READY mode is entered as a result of the determination in S30, the e-4WD system controls the actuator 2 to switch to D / C READY, and at the same time, the e-4WD system is also switched to the e-4WD motor synchronization state.

When the D / C READY mode is selected, a control command for one-stage rotation of the actuator 2 is generated as in S40, and the required current value of the actuator 2 for one-stage rotation is calculated as in S50. Activate the D / C motor (actuator 2). To do this, signals such as the wheel speeds of the left and right rear wheels, the steering angle, and the motor rpm of the e-4WD motor are used.

 When switching to e-4WD motor synchronization, the wheel speeds of the left and right rear wheels detected as in S40-1 are converted into wheel e-4WD motor RPM and the e-4WD motor target RPM (Target RPM) is calculated as S50-1 do. To do this, signals such as the wheel speeds of the left and right rear wheels, the steering angle, and the motor rpm of the e-4WD motor are used. In this embodiment, the e-4WD motor RPM and the e-4WD motor target RPM are calculated by the following equations.

- 수학식2

- Equation 2

- 수학식3

- Equation 3

Here, V _rpm is wheeled e-4WD motor RPM, V _{Target_rpm} is e-4WD motor target RPM, V _wheel is the left and right rear wheels of hwilsok (KPH), V _wheel L is the left rear wheel of hwilsok (KPH), V _wheel R (KPH) of the right rear wheel, G _gear is the gear ratio of the speed reducer, and R is the accompanied light of the tire.

The entry state into the D / C READY of the disconnector is illustrated in FIG. As shown in the figure, the actuator 2 is moved by? By the one-step rotation of the actuator 2, and the moving distance of ?? is compressed by the length of the first spring 3-1, - is reduced to Δα. On the other hand, the length of the second spring 3-2 is maintained at the length B before compression. In this state, the shift fork 5 and the sleeve 6 are located on the hub 7 side.

S70 is a step of determining whether the D / C ON signal is applied. When the D / C ON signal is not received, the Disconnector 1 and the e-4WD system maintain the standby state as in S70-1, It is switched to the operating state.

S80 is the operating state of the disconnector 1, and the e-4WD system calculates the required current value of the actuator 2 for two-stage rotation and then operates the D / C motor (actuator 2). S80-1 is the e-4WD motor ON state, and the e-4WD system controls the e-4WD inverter so that the e-4WD motor reaches the target RPM (Target RPM). Therefore, the disconnector 1 establishes a quick clutch engagement in the D / C ON state, and at the same time, the e-4WD motor achieves rapid RPM synchronization with the left and right rear wheels. In particular, the e-4WD motor speed control by the e-4WD inverter compares the wheel e-4WD motor RPM with the e-4WD motor RPM to reach the allowable RPM error.

 The D / C ON state of the disconnector is illustrated in FIG. As shown in the figure, the actuator 2 is moved by ?? by the two-step rotation of the actuator 2, and the moving distance of ?? is compressed by the length of the second spring 3-2, - Δβ. On the other hand, the length of the first spring 3-1 maintains the length A - DELTA alpha after compression by DELTA alpha. The shift of the actuator 2 causes the shift fork 5 to move and the shift of the shift fork 5 causes the sleeve 6 to move toward the input shaft 9-1 from the hub 7 side, Connects the hub 7 and the input shaft 9-1. As a result, the rotation of the input shaft 9-1 is transmitted to the output shaft 9-2 via the sleeve 6 and the hub 7, so that the clutch is engaged.

As described above, in the e-4WD system clutch control method according to the present embodiment, the vehicle speed detected when the sleeve 6 is in the D / C OFF state of the disconnected connector 1 with the input shaft 9-1 is determined , the e-4WD system switches the disconnector 1 to the D / C READY for holding the sleeve 6 with the input shaft 9-1, and at the same time, the e-4WD motor rotates the e- When the D / C ON signal is applied, the sleeve 6 is shifted to the D / C ON state by the input shaft 9-1 and the e-4WD motor is synchronized with the front and rear wheels The first and second springs 3-1 and 3-2, which are made in the D / C OFF state of the disconnector 1, are operated in the ON state of the e-4WD motor, 4WD motor rpm is prepared by the compression of the first and second springs 3-1 and 3-2 in advance, so that the D / C ON A command during spring compression and e-4WD motor rpm synchronization omitted is made responsive improved.

1: Disconnector 2: Actuator
3-1: First spring 3-2: Second spring
5: shift fork 6: sleeve
7: hub 9-1: input shaft
9-2: Output shaft

Claims (12)

(A) the vehicle speed detected in the D / C OFF state of the dis connector having the sleeve not engaged with the input shaft is determined as the D / C READY vehicle speed for preparing the clutch by the e-4WD system;
(B) The e-4WD system switches e-4WD motor to e-4WD motor synchronization to synchronize the e-4WD motor with the wheel of the right and left rear wheels while the disconnector is switched to D / C READY for engaging the sleeve with the input shaft. Conversion;
(C) When the D / C ON signal is applied by the e-4WD system at the time of vehicle speed detection, the sleeve is engaged with the input shaft to enter the D / C ON state, The e-4WD motor is turned ON to be synchronized with the front and rear wheel speeds;
Wherein the e-4WD system clutch control method comprises:
The method according to claim 1, wherein the D / C READY vehicle speed is 120 KPH or less in (A).
The control method according to claim 1, wherein in the step (B), the D / C READY switching is performed such that (b-1a) an actuator control command for moving the shift fork coupled to the sleeve (6) (b-2a) calculating the required current value of the actuator by the control command, and (b-3a) operating the actuator within a range that does not move the shift fork. Way.
[4] The method of claim 3, wherein the actuation of the actuator compresses the length of the first spring of the first and second springs provided on both left and right sides of the actuator to reduce the length before compression.
(B-1b) converts the wheel speed into a wheel e-4WD motor RPM such as an RPM (Revolution per Minute) of the e-4WD motor, , and (b-2b) calculating the e-4WD motor target RPM.
The wheel e-4WD motor according to claim 5, wherein the wheel e-4WD motor RPM

Calculated and, V _rpm is wheeled e-4WD motor RPM, V _wheel is the left and hwilsok (KPH), G _gear of the right rear wheel is a reduction gear ratio, R is e-4WD system, clutch control method according to claim Kyung accompanying tires.
6. The method of claim 5, wherein the e-4WD motor target RPM is

, _Wherein V _{Target_rpm} is the e-4WD motor target RPM, V _wheel L is the wheel speed of the left rear wheel (KPH), and V _wheel R is the wheel speed of the right rear wheel (KPH).
2. The method according to claim 1, wherein in the step (C), the D / C ON state is (c-1a) a control command of the actuator for moving the shift fork coupled with the sleeve is generated, ) The required current value of the actuator by the control command is calculated, and (c-3a) the actuator is operated within a range for moving the shift fork.
The e-4WD system clutch control method according to claim 8, wherein the actuation of the actuator compresses the length of the second spring of the first and second springs provided on both the left and right sides of the actuator to reduce the length before compression.
4WD inverter is controlled by the e-4WD system, (c-2b) the e-4WD inverter is controlled by the e-4WD inverter, And the e-4WD motor RPM is reached when an allowable RPM error is reached.
The method according to claim 1, wherein the D / C ON signal is applied when the vehicle speed is less than 120 KPH at the vehicle speed detection point.
The method according to claim 1, wherein a D / C OFF signal is applied when the vehicle speed is 120 KPH or more at the vehicle speed detection time point.

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