Vehicle drive system

Patent metadata

Field	Value
Publication number	US-2016288792-A1
Application number	US-201414915071-A
Country	US
Kind code	A1
Filing date	Dec 24, 2014
Priority date	Dec 27, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

The purpose of the present invention is to provide a vehicle drive system that can improve drive efficiency while maintaining vehicle stability. The drive state switching unit ( 64 ) comprises: a step (S 3 , S 105 ) in which a switch is made from 2WB to AWD on the basis of a cumulative slip point; a step (S 12 , S 303 ) in which a switch is made from 2WD to AWD on the basis of a calculated lateral G; a step (S 13 , S 109 , S 111 ) in which a switch is made from AWD to 2WD after the step (S 3 or S 105 ) under a first switching condition; and a step (S 13 , S 306 , S 308 ) in which a switch is made from AWD to 2WD after the step (S 12 or S 303 ) under a second switching condition. The first switching condition and the second switching condition are made to differ from one another.

First claim

1 . A vehicle drive system comprising:
a first drive device that drives a first drive wheel which is either one of a front wheel and a rear wheel of a vehicle; a second drive device that drives a second drive wheel which is the other one of the front wheel and the rear wheel of the vehicle; and a control device that controls the first drive device and the second drive device, and controls a drive state of the first drive wheel and the second drive wheel wherein the control unit includes: a slip-correlation-amount acquisition means for acquiring a slip-correlation amount correlated with excessive slip occurring in the vehicle; a vehicle-movement-correlation amount acquisition means for acquiring a vehicle-movement correlation amount correlated with tinning direction movement, or lateral movement of the vehicle; and a drive-state switching means for switching between an independent one side wheel chive state driving the vehicle by only either one of the first drive device or the second drive device, and an both side wheel drive state driving the vehicle by both of the first drive device and the second drive device, wherein the drive-state switching means executes; first both side wheel drive switching processing to switch from the independent one side wheel drive state to the both side wheel drive state, based on the slip-correlation amount acquired by the slip-correlation-amount acquisition means; second both side wheel drive switching processing to switch from the independent one side wheel drive state to the both side wheel drive state, based on the vehicle-movement correlation value acquired by the vehicle-movement-correlation amount acquisition means; first independent one side wheel drive switching processing to switch from the both side wheel drive state to the independent one side wheel drive state with a first switching condition, after the first both side wheel drive switching processing: and second independent one side wheel drive switching processing to switch from the both side wheel drive state to the independent one side wheel drive state with a second switching condition, after the second both side wheel drive switching processing, wherein the first switching condition and the second switching condition differ from one another.

2 . The vehicle drive system according to claim 1 ,
wherein the drive-state switching means switches to the both side wheel drive state after the first both side wheel drive switching processing, in a case of a condition for the first both side wheel drive switching processing being established in the both side wheel drive state after the second both side wheel drive switching processing, and executes the independent one side wheel drive switching processing with the first switching condition.

3 . The vehicle drive system according to claim 1 ,
wherein the drive-state switching means sets the first switching condition as a condition for which switching is more difficult than the second switching condition.

4 . The vehicle drive system according to claim 1 ,
wherein the drive-state switching means executes the first independent one side wheel drive switching processing based on the slip-correlation amount acquired by the slip-correlation-amount acquisition means and a speed correlation amount of the vehicle, in a case of the speed correlation amount of the vehicle becoming no more than a first speed threshold.

5 . A vehicle drive system comprising:
a first drive device that drives a first drive wheel which is either one of a front wheel and a rear wheel of a vehicle; a second chive device that drives a second drive wheel which is the other one of the front wheel and the rear wheel of the vehicle; and a control device that controls the first drive device and the second chive device, and controls a drive state of the first drive wheel and the second drive wheel, wherein the control unit includes: a drive-state switching means for switching between an independent one side wheel drive state driving the vehicle by only either one of the first drive device or the second drive device, and an both side wheel drive state driving the vehicle by both of the first drive device and the second drive device, wherein the drive-state switching means, in a case of the speed correlation amount of the vehicle becoming no more than the first speed threshold in the both side wheel drive state, maintains the both side wheel drive state or inhibits switching to the independent one side wheel drive state, until reaching at least a second speed threshold set to be at least the first speed threshold.

6 . The vehicle drive system according to claim 5 ,
wherein the control device further includes a slip-correlation-amount acquisition means for acquiring a slip-correlation amount correlated with excessive slip occurring in the vehicle, and wherein the drive state switching means, in a case of the speed correlation amount of the vehicle becoming no more than the first speed threshold in the both side wheel drive state, maintains the both side wheel drive state or inhibits switching to the independent one side wheel drive state, until becoming at least the second speed threshold set to be at least the first speed threshold, and the slip-correlation amount acquired by the slip-correlation-amount acquisition means becomes no more than a slip threshold in the both side wheel drive state.

7 . The vehicle drive system according to claim 2 ,
wherein the drive-state switching means sets the first switching condition as a condition for which switching is more difficult than the second switching condition.

8 . The vehicle drive system according to claim 2 ,
wherein the drive-state switching means executes the first independent one side wheel drive switching processing based on the slip-correlation amount acquired by the slip-correlation-amount acquisition means and a speed correlation amount of the vehicle, in a case of the speed correlation amount of the vehicle becoming no more than a first speed threshold.

9 . The vehicle drive system according to claim 3 ,
wherein the drive-state switching means executes the first independent one side wheel drive switching processing based on the slip-correlation amount acquired by the slip-correlation-amount acquisition means and a speed correlation amount of She vehicle, in a case of the speed correlation amount of the vehicle becoming no more than a first speed threshold.

10 . The vehicle drive system according to claim 7 ,
wherein the drive-state switching means executes the first independent one side wheel drive switching processing based on the slip-correlation amount acquired by the slip-correlation-amount acquisition means and a speed correlation amount of the vehicle, in a case of the speed correlation amount of the vehicle becoming no more than a first speed threshold.

Assignees

• Honda Motor Co Ltd

Inventors

• Ando Satoshi
• Kikuchi Masayuki
• Noguchi Masatoshi

Classifications

• B60W30/18172

  Preventing, or responsive to skidding of wheels · CPC title

• B60W2520/26

  Wheel slip · CPC title

• B60K6/365

  with the gears having orbital motion · CPC title

• B60K6/485

  Motor-assist type · CPC title

• B60Y2300/18175

  Preventing, or responsive to skidding of wheels · CPC title