Fault detecting apparatus for four-wheel drive vehicle

• US 20060041346A1
• Filed: 08/19/2005
• Published: 02/23/2006
• Est. Priority Date: 08/23/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Sugo, Yasuhiko
• Granted Patent: US 7,082,358 B2
• Time in Patent Office: Days
• US Class Current: 701/33
• CPC Class Codes: B60K 17/35 including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches differential gearing with locking devices F16H48/20
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: F16H 2048/368 using additional orbital gears in combination with clutches or brakes
• CPC Class Codes: F16H 48/36 characterised by intentionally generating speed difference between outputs

Abstract

A fault detecting apparatus for a four-wheel drive vehicle is provided for avoiding without fail any erroneous detection due to a response delay associated with an operation for switching a speed increasing system and due to sudden fluctuations in wheel speed, to highly accurately detect a fault in the speed increasing system. The speed increasing system is configured to transmit a driving force of a prime mover directly to main driving wheels and to sub-driving wheels through associated clutches, and to increase rotational speed of the sub-driving wheels above rotational speed of the main driving wheels when a speed increase instruction signal is outputted. The fault detecting apparatus comprises an S-AWD•ECU for detecting a fault in the speed increasing system, and for disabling the fault detection until a predetermined time has elapsed after a speed increase instruction signal was outputted or after the output of the speed increase instruction signal was stopped.

Claims

1. A fault detecting apparatus for detecting a fault in a speed increasing system in a four-wheel drive vehicle configured to transmit a driving force of a prime mover directly to a left and a right main driving wheel and to a left and a right sub-driving wheel through a clutch, wherein said speed increasing system is configured to increase a rotational speed of the sub-driving wheels above a rotational speed of the main driving wheels when a speed increasing instruction signal is outputted, said apparatus comprising:

fault detecting means for detecting a fault in said speed increasing system; and

fault detection disabling means for disabling the detection of a fault by said fault detecting means until a predetermined time has elapsed after the speed increase instruction signal was outputted or after the output of the speed increase instruction signal was stopped.

2. A fault detecting apparatus for a four-wheel drive vehicle according to claim 1, further comprising wheel speed detecting means for detecting the respective rotational speeds of the main driving wheels and the sub-driving wheels,

wherein said fault detection disabling means disables the fault detection made by said fault detecting means when a difference between the detected rotational speed of the main driving wheels and the detected rotational speed of the sub-driving wheels is larger than a predetermined value.

3. A fault detecting apparatus for a four-wheel drive vehicle according to claim 1, wherein:

said four-wheel drive vehicle comprises a braking controller for conducting a predetermined braking control for at least one of the main driving wheels and the sub-driving wheels,

wherein said fault detection disabling means disables the fault detection made by said fault detecting means when said braking controller is conducting the predetermined braking control.