Four-wheel steering apparatus for vehicles
AssigneeMazda Motor Corporation
InventorAkihiko Miyoshi
Life of this patent
Estimating the term…
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 the turning ratio is changed in the reverse phase direction as compared with when the turning ratio is changed in the same phase direction.
Claims19
In a four-wheel steering apparatus for a vehicle equipped with a front wheel turning mechanism for turning the front wheels and a rear wheel turning mechanism for turning the rear wheels and designed to turn the rear wheels in association with the front wheels in response to the operation of a steering wheel, a four-wheel steering apparatus comprising:
- turning ratio changing means for changing a turning ratio of a turning angle of the rear wheel to that of the front wheel;
- changing direction discriminating means for determining whether the turning ratio is changed in the same phase direction or in the reverse phase direction;
- and
- changing-speed altering means for delaying a speed of changing the turning ratio when the turning ratio is changed in the reverse phase direction, as compared with when the turning ratio is changed in the same phase direction in response to an output from said changing direction discriminating means.
In a four-wheel steering apparatus for a vehicle equipped with a front wheel turning mechanism for turning the front wheels and a rear wheel turning mechanism for the turning the rear wheels and designed to turn the rear wheels in association with the front wheels in response to the operation of a steering wheel, a four-wheel steering apparatus comprising of:
- turning ratio changing means for changing a turning ratio of a turning angle of the rear wheel to that of the rear wheel;
- memory means for meomrizing turning ratio characteristics predetermined in accordance with the 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 rartio 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 to become the target turning ratio;
- changing direction discriminating means for discriminating whether the changing direction of the turning ratio is in the same phase direction or in the reverse phase direction;
- and
- changing speed altering means for delaying the changing speed of the turning ratio when the changing direction of the turning ratio is in the reverse phase direction, as compared with when the turning ratio is changed in the same phase direction.
In a four-wheel steering apparatus for a vehicle equipped with a front wheel turning mechanism for turning the front wheels and a rear wheel turning mechanism for turning the rear wheels and designed to turn the rear whels in association with the front wheels in response to the operation of a steering wheel, a four-wheel steering apparatus comprising of:
- an electromagnetic actuator for turning the rear wheels by driving the rear wheel trning mechanism;
- turning angle detecting means for detecting a turning angle of the steering wheel;
- target turning ratio determining means for determining a target turning ratio on the basis of a predetermined turning ratio characteristics;
- integrating means for integrating a signal from the target turning ratio determining means on the basis of a predetermined time constant;
- discriminating means for discriminating whether the direction of changing the turning ratio is in the same phase direction or in the reverse phase direction by comparing from the target turning ratio determining means with a signal from the integrating means;
- time constant setting means for setting the time constant received from the discriminating means so as to become larger when the directin of changing the turning ratio is in the reverse phase direction rather than when the direction of changing the turning ratio is in the same phase direction;
- target turning angle determining means for determining a target turning angle of the rear wheel on the basis of outputs from the integrating means and the turning angle detecting means;
- and
- drive controlling means for controlling the actuator so as to become the target turning angle.
Dependencies are inferred from the claim text.