Control system for four-wheel drive vehicle
First Claim
1. A control system for a four-wheel drive vehicle including a center differential provided between a front shaft, which transmits engine power to a front differential, and a rear shaft, which transmits engine power to a rear differential, said front differential and said rear differential each being provided between a right wheel and a left wheel, said control system comprising:
- first means provided in the center differential for restricting a differential between the front shaft and the rear shaft;
second means provided in at least one of the front differential and the rear differential for restricting a differential between at least one right wheel and at least one left wheel; and
controlling means for controlling the restricting operations carried out by the first means and the second means;
said controlling means including operational timing controlling means for controlling operational timings in the first means and the second means so that a timing when the first means maintains the center differential in a locking condition is different from a timing when the second means maintains the at least one of the front differential and the rear differential in a locking condition.
1 Assignment
0 Petitions
Accused Products
Abstract
A control system for a four-wheel drive vehicle includes a first differential provided between a front shaft and a rear shaft and a second differential provided between a right wheel and a left wheel. The control system comprises a first device provided in the first differential for restricting a differential between the front shaft and the rear shaft, a second device provided in the second differential for restricting a differential between the right wheel and the left wheel, and a device for controlling the restricting operations carried out by the first device and the second device. The controlling device includes a device for controlling operational timings in the first device and the second device so that the timing when the first device maintains the first differential in locking condition is different from the timing when the second device maintains the second differential in locking condition.
37 Citations
14 Claims
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1. A control system for a four-wheel drive vehicle including a center differential provided between a front shaft, which transmits engine power to a front differential, and a rear shaft, which transmits engine power to a rear differential, said front differential and said rear differential each being provided between a right wheel and a left wheel, said control system comprising:
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first means provided in the center differential for restricting a differential between the front shaft and the rear shaft; second means provided in at least one of the front differential and the rear differential for restricting a differential between at least one right wheel and at least one left wheel; and controlling means for controlling the restricting operations carried out by the first means and the second means; said controlling means including operational timing controlling means for controlling operational timings in the first means and the second means so that a timing when the first means maintains the center differential in a locking condition is different from a timing when the second means maintains the at least one of the front differential and the rear differential in a locking condition. - View Dependent Claims (2, 3, 4, 5, 6, 9)
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7. A control system for a four-wheel drive vehicle including a center differential provided between a front shaft, which transmits engine power to a front differential, and a rear shaft, which transmits engine power to a rear differential, said front differential and said rear differential each being provided between a right wheel and a left wheel, said control system comprising:
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first means provided in the center differential for restricting a differential between the front shaft and the rear shaft; second means provided in at least one of the front differential and the rear differential for restricting a differential between at least one right wheel and at least one left wheel; and controlling means for controlling the restricting operations carried out by the first means and the second means; said first and second means including friction engaging devices, each of which respectively restricts the differentials in one of the center differential and the at least one of the front differential and the rear differential by applying a proportional friction force to one of the center differential and the at least one of the front differential and the rear differential, said controlling means including change rate controlling means for controlling rates of change in the friction forces applied to the center and at least one of the front and rear differentials by the friction engaging devices so that the rate of change in the friction force applied to the center differential is different from the rate of change in the friction force applied to the at least one of the front differential and the rear differential. - View Dependent Claims (8, 10)
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11. A control system for a four-wheel vehicle including a first differential provided between a front shaft and a rear shaft and a second differential provided between a right wheel and a left wheel, said control system comprising:
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first means provided in the first differential for restricting a differential between the front shaft and rear shaft; second means provided in the second differential for restricting a differential between the right wheel and the left wheel; and controlling means for controlling the restricting operation carried out by the first means and the second means; said controlling means including means for controlling operational timings in the first means and the second means so that the timing when the first means maintains the first differential in a locking condition is different from the timing when the second means maintains the second differential in a locking condition, and the timing when the first means releases the first differential from the locking condition is different from the timing when the second means releases the second differential from the locking condition.
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12. A control system for a four-wheel vehicle including a first differential provided between a front shaft and a rear shaft and a second differential provided between a right wheel and a left wheel, said control system comprising:
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first means provided in the first differential for restricting a differential between the front shaft and the rear shaft; second means provided in the second differential for restricting a differential between the right wheel and the left wheel; and controlling means for controlling the restricting operation carried out by the first means and the second means; said controlling means including means for controlling operational timings in the first means and the second means so that the timing when the first means maintains the first differential in a locking condition is different from the timing when the second means maintains the second differential in a locking condition, and the timing when the first means operates the first differential to be in the locking condition is different from the timing when the second means operates the second differential to be in the locking condition.
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13. A control system for a four-wheel vehicle including a first differential provided between a front shaft and a rear shaft and a second differential provided between a right wheel and a left wheel, said control system comprising:
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first means provided in the first differential for restricting a differential between the front shaft and the rear shaft; second means provided in the second differential for restricting a differential between the right wheel and the left wheel; and controlling means for controlling the restricting operation carried out by the first means and the second means; said controlling means includes means for controlling operational timings in the first means and the second means so that the timing when the first means maintains the first differential in a locking condition is different from the timing when the second means maintains the second differential in a locking condition, and, when one of the first and second means releases one of the first and the second differentials after the first and second means maintain the first and second differentials in the locking condition, the other of the first and second means releases the other of the first and second differentials after the one of the first and second means has released one of the first and second differentials for a predetermined time.
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14. A control system for a four-wheel vehicle including a first differential provided between a front shaft and a rear shaft and a second differential provided between a right wheel and a left wheel, said control system comprising:
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first means provided in the first differential for restricting a differential between the front shaft and the rear shaft; second means provided in the second differential for restricting a differential between the right wheel and the left wheel; and means for controlling the restricting operation carried out by the first means and the second means; said controlling means including means for controlling operational timings in the first means and the second means so that the timing when the first means maintains the first differential in a locking condition is different from the timing when the second means maintains the second differential in a locking condition, wherein the first differential is operated to be in the locking condition in an early stage in comparison with the second differential while the vehicle is traveling at a speed which is less than a predetermined value and the second differential is operated to be in locking condition in an early stage in comparison with the first differential while the vehicle is traveling at a speed which is at least equal to the predetermined value.
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Specification