Driving force distribution control system for vehicle

Patent metadata

Field	Value
Publication number	US-11097612-B1
Application number	US-202017102102-A
Country	US
Kind code	B1
Filing date	Nov 23, 2020
Priority date	Feb 6, 2020
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A driving force distribution control system for a four-wheel drive vehicle is provided. The four-wheel drive vehicle uses front wheels as main driving wheels, and when a towed vehicle is coupled to a coupling part provided to a rear part of the four-wheel drive vehicle, the towed vehicle has the center of gravity position so that a downward load in a vehicle up-and-down direction is applied to the rear part of the vehicle through the coupling part. A driving force distribution control device includes a towing determination module configured to determine whether the vehicle is towing the towed vehicle, and when it is determined that the vehicle is towing the towed vehicle, a driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to rear wheels becomes larger than that when the four-wheel drive vehicle is not towing the towed vehicle.

First claim

What is claimed is:

1. A driving force distribution control system for a four-wheel drive vehicle, configured to control a distributing amount of a driving force of front and rear wheels of the vehicle capable of towing a towed vehicle, comprising:
a driving force distributing device configured to distribute the driving force of the front and rear wheels of the four-wheel drive vehicle; and
a driving force distribution control device configured to control the driving force distributing amount of the front and rear wheels by the driving force distributing device,
wherein the four-wheel drive vehicle uses the front wheels as main drive wheels and distributes the driving force of the front wheels to the rear wheels through the driving force distributing device,
wherein, when the towed vehicle is coupled to a coupling part provided to a rear part of the four-wheel drive vehicle, the towed vehicle has the center of gravity position so that a downward load in a vehicle up-and-down direction is applied to the rear part of the four-wheel drive vehicle through the coupling part,
wherein the driving force distribution control device includes a processor configured to execute a towing determination module to determine whether the four-wheel drive vehicle is towing the towed vehicle, and
wherein, when the towing determination module determines that the four-wheel drive vehicle is towing the towed vehicle, the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger than the driving force distributing amount when the towing determination module determines that the four-wheel drive vehicle is not towing the towed vehicle.

2. The driving force distribution control system of claim 1 , wherein the processor is further configured to execute:
a basic driving force distribution ratio determination module to determine a basic driving force distribution ratio of the front and rear wheels of the four-wheel drive vehicle, when the towing determination module determines that the four-wheel drive vehicle is not towing the towed vehicle and/or an accelerator opening sensor does not detect a demanded acceleration by a driver; and
a driving force distribution ratio correction module to correct the basic driving force distribution ratio so that the driving force distribution ratio to the rear wheels is increased relative to the basic driving force distribution ratio of the front and rear wheels determined by the basic driving force distribution ratio determination module, when the towing determination module determines that the four-wheel drive vehicle is towing the towed vehicle and the accelerator opening sensor detects the driver's demanded acceleration, and
wherein, when the towing determination module determines that the four-wheel drive vehicle is towing the towed vehicle and the accelerator opening sensor detects the driver's demanded acceleration, the driving force distribution control device calculates the driving force distributing amount to the rear wheels based on the driving force distribution ratio corrected by the driving force distribution ratio correction module, and controls the driving force distributing device based on the driving force distributing amount to the rear wheels.

3. The driving force distribution control system of claim 2 , wherein the driving force distribution control device further includes the accelerator opening sensor configured to detect the driver's demanded acceleration of the four-wheel drive vehicle, and
wherein, when the towing determination module determines that the four-wheel drive vehicle is towing the towed vehicle, the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger as the driver's demanded acceleration detected by the accelerator opening sensor increases.

4. The driving force distribution control system of claim 2 , wherein the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger as the weight of the towed vehicle increases.

5. The driving force distribution control system of claim 3 , wherein the processor is further configured to execute a towed-vehicle load detection module to detect a load of the towed vehicle applied to the rear part of the four-wheel drive vehicle, and
wherein the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger as the load detected by the towed-vehicle load detection module increases.

6. The driving force distribution control system of claim 5 , wherein the towing determination module of the driving force distribution control device determines that the four-wheel drive vehicle is towing the towed vehicle, when a towing mode is selected by the driver via a towing mode switch.

7. The driving force distribution control system of claim 6 , further comprising a towing sensor configured to determine whether the towed vehicle is coupled to the coupling part provided to the rear part of the four-wheel drive vehicle,
wherein, while the towing sensor determines that the towed vehicle is coupled, the towing determination module of the driving force distribution control device accepts a selection of the towing mode by the driver and determines that the four-wheel drive vehicle is towing the towed vehicle.

8. The driving force distribution control system of claim 1 , wherein the driving force distribution control device further includes an accelerator opening sensor configured to detect the demanded acceleration by a driver of the four-wheel drive vehicle, and
wherein, when the towing determination module determines that the four-wheel drive vehicle is towing the towed vehicle, the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger as the driver's demanded acceleration detected by the accelerator opening sensor increases.

9. The driving force distribution control system of claim 1 , wherein the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger as the weight of the towed vehicle increases.

10. The driving force distribution control system of claim 1 , wherein the processor is further configured to execute a towed-vehicle load detection module configured to detect a load of the towed vehicle applied to the rear part of the four-wheel drive vehicle, and
wherein the driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to the rear wheels of the four-wheel drive vehicle becomes larger as the load detected by the towed-vehicle load detection module increases.

11. The driving force distribution control system of claim 1 , wherein the towing determination module of the driving force distribution control device determines that the four-wheel drive vehicle is towing the towed vehicle, when a towing mode is selected by a driver.

12. The driving force distribution control system of claim 1 , further comprising a towing sensor configured to determine whether the towed vehicle is coupled to the

Assignees

• Mazda Motor

Inventors

• Imamura Yasumasa
• Umetsu Daisuke
• Fujioka Yoichi
• Nobutani Naoki

Classifications

• B60Y2400/4244

  of wet type, e.g. using multiple lamellae · CPC title

• B60Y2300/28

  related to towing or towed situations · CPC title

• B60K2023/0833

  for adding torque to the rear wheels · CPC title

• B60K23/0808 Primary

  for varying torque distribution between driven axles, e.g. by transfer clutch · CPC title

• B60K17/348

  having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed (B60K17/346 takes precedence) · CPC title