US 2011/0257858 A1 · DRIVE STATE CONTROL APPARATUS FOR VEHICLE

Abstract

A drive state control apparatus is applied to a vehicle which has not only a transfer including a multi-disc clutch mechanism but also a changeover mechanism interposed in an axle and which can be switched between 2WD and 4WD. When a 2WD-to-4WD changeover condition is satisfied, the multi-disc clutch is immediately switched from a “decoupled state” to a “coupled state.” Meanwhile, a connecting operation of the changeover mechanism is started upon establishment of a state in which left and right rear wheels have no acceleration slippage, and a state in which rotational speeds of first and second axles on opposite sides of the changeover mechanism are approximately equal to each other. In addition, in the case where the left and right rear wheels have acceleration slippage after the 2WD-to-4WD changeover condition has been satisfied, an E/G output reduction control is executed. Thus, the connecting operation can be performed smoothly.

Claims9

Dependent claims

1-8. (canceled)

A drive state control apparatus applied for a vehicle which comprises:

a transfer which includes an input shaft connected to an output shaft of a transmission connected to a power source of the vehicle, a first output shaft connected to a first propeller shaft, which is one of front-wheel-side and rear-wheel-side propeller shafts of the vehicle, a second output shaft connected to a second propeller shaft, which is the other of the front-wheel-side and rear-wheel-side propeller shafts, and a first changeover mechanism which is switchable between a first state in which a power transmission system is formed only between the input shaft and the first output shaft and a second state in which power transmission systems are formed between the input shaft and the first and second output shafts;
a first differential which is connected to the first propeller shaft and distributes torque of the first propeller shaft to first left and right wheels, which are left and right front wheels or left and right rear wheels, via axles of the first left and right wheels, while allowing difference in rotational speed between the first left and right wheels;
a second differential which is connected to the second propeller shaft and distributes torque of the second propeller shaft to second left and right wheels, which are the remaining left and right wheels, via axles of the second left and right wheels, while allowing difference in rotational speed between the second left and right wheels;
and
a second changeover mechanism which is interposed in an axle of a specific wheel, which is one of the second left and right wheels, and is switchable between a connected state in which a power transmission system is formed between the specific wheel and the second differential, and a disconnected state in which no power transmission system is formed between the specific wheel and the second differential,
wherein the vehicle travels in a two-wheel drive state when the first changeover mechanism is in the first state and the second changeover mechanism is in the disconnected state, and travels in a four-wheel drive state when the first changeover mechanism is in the second state and the second changeover mechanism is in the connected state,
the drive state control apparatus comprising:
first rotational speed acquisition means for acquiring rotational speed of a first axle, which is a portion of the axle of the specific wheel located between the second changeover mechanism and the specific wheel;
second rotational speed acquisition means for acquiring rotational speed of a second axle, which is a portion of the axle of the specific wheel located between the second changeover mechanism and the second differential;
and
control means for controlling the first changeover mechanism and the second changeover mechanism,
wherein the control means is configured such that, when a condition for changeover from the two-wheel drive state to the four-wheel drive state is satisfied while the vehicle is traveling in the two-wheel drive state, the control means switches the first changeover mechanism from the first state to the second state, and starts a connecting operation for switching the second changeover mechanism from the disconnected state to the connected state, upon determination that a difference between the acquired rotational speeds of the first and second axles is less than a predetermined value.

9 more elements

A drive state control apparatus applied for a vehicle which comprises:

a transfer which includes an input shaft connected to an output shaft of a transmission connected to a power source of the vehicle, a first output shaft connected to a first propeller shaft, which is one of front-wheel-side and rear-wheel-side propeller shafts of the vehicle, a second output shaft connected to a second propeller shaft, which is the other of the front-wheel-side and rear-wheel-side propeller shafts, and a first changeover mechanism which is switchable between a first state in which a power transmission system is formed only between the input shaft and the first output shaft and a second state in which power transmission systems are formed between the input shaft and the first and second output shafts;
a first differential which is connected to the first propeller shaft and distributes torque of the first propeller shaft to first left and right wheels, which are left and right front wheels or left and right rear wheels, via axles of the first left and right wheels, while allowing difference in rotational speed between the first left and right wheels;
a second differential which is connected to the second propeller shaft and distributes torque of the second propeller shaft to second left and right wheels, which are the remaining left and right wheels, via axles of the second left and right wheels, while allowing difference in rotational speed between the second left and right wheels;
and
a second changeover mechanism which is interposed in an axle of a specific wheel, which is one of the second left and right wheels, and is switchable between a connected state in which a power transmission system is formed between the specific wheel and the second differential, and a disconnected state in which no power transmission system is formed between the specific wheel and the second differential,
wherein the vehicle travels in a two-wheel drive state when the first changeover mechanism is in the first state and the second changeover mechanism is in the disconnected state, and travels in a four-wheel drive state when the first changeover mechanism is in the second state and the second changeover mechanism is in the connected state,
the drive state control apparatus comprising:
first rotational speed acquisition means for acquiring rotational speed of the first output shaft;
second rotational speed acquisition means for acquiring rotational speed of the second output shaft;
and
control means for controlling the first changeover mechanism and the second changeover mechanism,
wherein the control means is configured such that, when a condition for changeover from the two-wheel drive state to the four-wheel drive state is satisfied while the vehicle is traveling in the two-wheel drive state, the control means switches the second changeover mechanism form the disconnected state to the connected state, and starts a connecting operation for switching the first changeover mechanism from the first state to the second state, upon determination that a difference between the acquired rotational speeds of the first and second output shafts is less than a predetermined value.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application

13/033,944Filed 24 Feb 2011

Priority

JP 2010-04133526 Feb 2010

Published

20 Oct 2011

Term ends

Not estimatedThe source records don’t support an estimate.

Classification13 codes

B60W 30/18172
Propelling the vehicle: preventing, or responsive to skidding of wheels
B60K 17/3462
The transfer gear being a differential gear: with means for changing distribution of torque between front and rear wheels
B60K 23/08
Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for: for changing number of driven…
B60W 10/119
Conjoint control of vehicle sub-units of different type or different function: including control of all-wheel-driveline means, e.g. transfer gears…

Drive state control apparatus for vehicle

Life of this patent

Drive state control apparatus for vehicle

Life of this patent

Abstract

Claims9