초록 ▼

In a variable gear ratio steering device comprising a rack and pinion gear mechanism, the rack of the rack and pinion gear mechanism is provided with tooth pitch distribution for producing a variable rack gain property in relation to a steering input which includes, in each rotational sense, a low f

In a variable gear ratio steering device comprising a rack and pinion gear mechanism, the rack of the rack and pinion gear mechanism is provided with tooth pitch distribution for producing a variable rack gain property in relation to a steering input which includes, in each rotational sense, a low fixed rack gain region near a neutral position, a high fixed rack gain region in a large steering input region, and a progressively increasing rack gain region connected to the low fixed rack gain region via a first point of inflection and to the high fixed rack gain region via a second point of inflection. Because the point of inflection or the point of transition from a fixed low rack gain region to a region of a progressively increasing rack gain falls inside the region of the play of the steering mechanism, the vehicle operator would not be affected by the presence of the point of inflection because as soon as the steering wheel is turned beyond the play or the dead zone near the neutral position of the steering wheel the point of inflection has already been passed. Another point of inflection or the point of transition between the region of the progressively increasing rack gain and the fixed high rack gain region also would not affect the vehicle operator because it is located well outside the range of normal operation in a medium to high speed range, and it will not be noticeable in a low speed range even when the steering angle passes this point.

대표청구항 ▼

In combination, a variable gear ratio steering device, and an overall steering system of a vehicle including a steering wheel and a steering input, the variable gear ratio steering device comprising: a pinion functionally coupled to the steering wheel; and a rack meshing with the pinion, wherein the

In combination, a variable gear ratio steering device, and an overall steering system of a vehicle including a steering wheel and a steering input, the variable gear ratio steering device comprising: a pinion functionally coupled to the steering wheel; and a rack meshing with the pinion, wherein the rack has a tooth pitch distribution for producing a variable rack gain property in relation to the steering input which includes, in each rotational sense, a low fixed rack gain region near a neutral position, a high fixed rack gain region in a large steering input region, and a progressively increasing rack gain region connected to the low fixed rack gain region via a first point of inflection and to the high fixed rack gain region via a second point of inflection, and further wherein the first point of inflection is located within a first angle at the neutral position of an amount within a play in the overall steering system of the vehicle.