For a four-wheel-drive vehicle
First Claim
1. A drive-force distribution controller for a four-wheel-drive vehicle in which drive force produced by a prime mover is transmitted directly to front or rear wheels and is transmitted to the remaining wheels via a torque distribution clutch, and the engagement force of the torque distribution clutch is controlled in accordance with traveling conditions of the vehicle, the drive-force distribution controller comprising:
- a calculation unit for calculating variation per unit time in rotational speed difference between the front wheels and the rear wheels; and
a control unit for controlling the engagement force such that the engagement force increases as the variation per unit time in the rotational speed difference increases.
1 Assignment
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Accused Products
Abstract
A drive-force distribution controller for a four-wheel-drive vehicle in which drive force produced by an engine is transmitted directly to front or rear wheels and is transmitted to the remaining wheels via a torque distribution clutch, and the engagement force of the torque distribution clutch is controlled in accordance with traveling conditions of the vehicle. The controller includes a calculation unit for calculating variation per unit time in rotational speed difference between the front wheels and the rear wheels; and a control unit for controlling the engagement force such that the engagement force increases as the variation per unit time in the rotational speed difference increases. Alternatively, the controller includes a first judgment unit for judging which is greater, the rotational speed of the front wheels or the rotational speed of the rear wheels; and a second judgment unit which is enabled when the first judgment unit has judged that the rotational speed of the front wheels is greater than the rotational speed of the rear wheels, in order to judge whether the acceleration of the vehicle is greater than a predetermined level. The engagement force of the torque distribution clutch is controlled in accordance with results of the judgments performed by the first and second judgment units.
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Citations
11 Claims
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1. A drive-force distribution controller for a four-wheel-drive vehicle in which drive force produced by a prime mover is transmitted directly to front or rear wheels and is transmitted to the remaining wheels via a torque distribution clutch, and the engagement force of the torque distribution clutch is controlled in accordance with traveling conditions of the vehicle, the drive-force distribution controller comprising:
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a calculation unit for calculating variation per unit time in rotational speed difference between the front wheels and the rear wheels; and
a control unit for controlling the engagement force such that the engagement force increases as the variation per unit time in the rotational speed difference increases. - View Dependent Claims (2, 3, 4, 5)
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6. A drive-force distribution controller for a four-wheel-drive vehicle in which drive force produced by a prime mover is transmitted directly to front wheels and is transmitted to rear wheels via a torque distribution clutch, and the engagement force of the torque distribution clutch is controlled in accordance with traveling conditions of the vehicle, the drive-force distribution controller comprising:
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a first judgment unit for judging which is greater;
the rotational speed of the front wheels or the rotational speed of the rear wheels;
a second judgment unit which is enabled when the first judgment unit has judged that the rotational speed of the front wheels is greater than the rotational speed of the rear wheels, in order to judge whether the acceleration of the vehicle is greater than a predetermined level;
a first setting unit for setting the engagement force to a relatively large first value when the second judgment unit has judged that the acceleration of the vehicle is greater than the predetermined level;
a second setting unit for setting the engagement force to a second value smaller than the first value when the second judgment unit has judged that the acceleration of the vehicle is not greater than the predetermined level; and
a third setting unit for setting the engagement force to a third value smaller than the first value but greater than the second value when the first judgment unit has judged that the rotational speed of the front wheels is less than the rotational speed of the rear wheels. - View Dependent Claims (7, 8)
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9. A drive force distribution controller for a four-wheel-drive vehicle in which drive force produced by a prime mover is transmitted directly to rear wheels and is transmitted to front wheels via a torque distribution clutch, and the engagement force of the torque distribution clutch is controlled in accordance with traveling conditions of the vehicle, the drive-force distribution controller comprising:
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a first judgment unit for judging which is greater;
the rotational speed of the front wheels or the rotational speed of the rear wheels;
a first setting unit for setting the engagement force to a relatively large first value when the first judgment unit has judged that the rotational speed of the front wheels is less than the rotational speed of the rear wheels; and
a second setting unit for setting the engagement force to a second value smaller than the first value when the first judgment unit has judged that the rotational speed of the front wheels is greater than the rotational speed of the rear wheels, wherein the second value increases with the speed of the vehicle. - View Dependent Claims (10, 11)
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Specification