Four-wheel steering apparatus for vehicles
First Claim
1. In a four-wheel steering apparatus for a vehicle with a front wheels turning mechanism and a rear wheels turning mechanism constructed so as to cause the rear wheels to be turned in association with the front wheels in response to a steering wheel, the four-wheel steering apparatus comprises:
- turning ratio changing means for changing a turning ratio of the rear wheel to the front wheel;
sliding state detecting means for detecting a sliding state of a road surface or a road surface friction coefficient μ
; and
changing speed altering means for altering the changing speed of turning ratios so as to be delayed when the road surface is more slidable or slippery or when the road surface friction coefficient μ
is smaller than when the road surface is less slidable or less slippery or when the road surface friction coefficient μ
is larger.
1 Assignment
0 Petitions
Accused Products
Abstract
The rear wheels of a vehicle are turned together with the front wheels in response to the operation of a steering wheel. Turning ratio changing means is provided so as to be able to change a turning ratio of the rear wheels to the front wheels. In altering the turning ratio, a speed of changing the turning ratio is designed to get delayed when a road surface is more slidable or slippery, i.e., a road surface friction coefficient μ is smaller, as compared to when a road surface is less slidable or less slippery, i.e., a road surface friction coefficient μ is larger.
16 Citations
23 Claims
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1. In a four-wheel steering apparatus for a vehicle with a front wheels turning mechanism and a rear wheels turning mechanism constructed so as to cause the rear wheels to be turned in association with the front wheels in response to a steering wheel, the four-wheel steering apparatus comprises:
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turning ratio changing means for changing a turning ratio of the rear wheel to the front wheel; sliding state detecting means for detecting a sliding state of a road surface or a road surface friction coefficient μ
; andchanging speed altering means for altering the changing speed of turning ratios so as to be delayed when the road surface is more slidable or slippery or when the road surface friction coefficient μ
is smaller than when the road surface is less slidable or less slippery or when the road surface friction coefficient μ
is larger. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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2. In a four-wheel steering apparatus for a vehicle with a front wheels turning mechanism and a rear wheels turning mechanism constructed so as to cause the rear wheels to be turned in association with the front wheels in response to a steering wheel, the four-wheel steering apparatus comprises:
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turning ratio changing means for changing a turning ratio of the rear wheel to the front wheel; memory means for memorizing turning ratio characteristics set in accordance with a running state of the vehicle; running state detecting means for detecting the running state of the vehicle; target turning ratio determining means for determining a target turning ratio on the basis of the turning ratio characteristics in accordance with the running state of the vehicle; turning ratio change controlling means for controlling the turning ratio changing means so as to become the target turning ratio; sliding state detecting means for detecting a sliding state of a road surface or a road surface friction coefficient μ
; andchanging speed altering means for altering the changing speed of turning ratios so as to be delayed when the road surface is more slidable or slippery or when the road surface friction coefficient μ
is smaller than when the road surface is less slidable or less slippery or when the road surface friction coefficient μ
is larger. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 22, 23)
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Specification