US 12,411,055 B2Granted

Method and test bench for predicting pressure oscillations in a vehicle tire

AssigneeZF Friedrichshafen AG

InventorsJens Eisenbeiss, Roland Bösl

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Abstract

A test bench and a method to predict pressure oscillations in a vehicle tire. The tire is rotatably positioned, via a bearing on a test bench rim, the tire is pressurized with fluid, a load is applied on the tire, the tire is accelerated according to pre-determinable speed ramp to a final speed, the fluid in accordance with the tire speed, undergoes an oscillation excitation, and reacts to the oscillation excitation with a pressure oscillation. The method is characterized in that an effective force of the tire, due to the pressure oscillation, at the bearing is continuously detected, and that a descriptive data set is determined for the tire speed over the frequency, a timing signal of the speed ramp undergoes a Fourier transformation and, in an analogous manner, a reference data set is created through the use of a vehicle rim instead of the test bench rim.

Claims13

Dependent claims

A method for predicting pressure oscillations in a vehicle tire that is mounted on either a test bench rim or a vehicle rim which is rotatably mounted, via a wheel bearing, on a test bench, an interior of the vehicle tire being pressurized with a fluid to a fluid pressure, the vehicle tire being subjected to a wheel load, the vehicle tire being rotationally accelerated in accordance with a predetermined speed ramp from an initial tire speed at a start time of the speed ramp to a final tire speed at an end time of the speed ramp, wherein during rotation of the vehicle tire from the start time to the end time of the speed ramp, the fluid within the vehicle tire undergoes tire speed dependent oscillation excitation, and the oscillation excitation of the fluid causes pressure oscillation of the fluid within the vehicle tire which is detectable as a force acting from the vehicle tire on the wheel bearing, the method comprising:

mounting the vehicle tire on one of the test bench rim and the vehicle rim which is rotatably mounted, via the wheel bearing, on the test bench,
from the start time to the end time of the speed ramp continuously detecting, at the wheel bearing, the forces acting on the vehicle tire due to the pressure oscillation, the forces being detected at the wheel bearing with force sensors,
generating a data set that characterize the forces acting on the wheel bearing from the vehicle tire over the tire speeds of the speed ramp and over frequencies of tire oscillations and frequencies of the pressure oscillations by subjecting a time signal of the speed ramp to a Fourier transformation,
when the vehicle tire is mounted on the test bench rim, the data set is a generated data set, and
when the vehicle tire is mounted on the vehicle rim, the data set is a reference data set, and
repeating the method with the vehicle tire being mounted on the other one of the test bench rim and the vehicle rim,
determining the pressure oscillations in the vehicle tire by comparing the forces acting on the wheel bearing over the frequencies of tire oscillations in the generated data set relative to a ratio of the forces acting on the wheel bearing over the frequencies of the tire oscillations and the frequencies of the pressure oscillations in the reference data set.

4 more elements

A test bench for predicting pressure oscillations in a vehicle tire , comprising:

a test bench rim,
a vehicle rim,
a wheel bearing,
means for pressurizing the vehicle tire,
means applying a wheel load on the vehicle tire,
means for accelerating the vehicle tire,
an optical, magnetic or electromagnetic means for detecting a tire rotational speed, the optical, magnetic or electromagnetic means being configured to detect an angle of rotation per unit of time,
means for detecting at least one of a force, a tire oscillation, and a pressure oscillation,
the vehicle tire being positioned on the test bench rim or the vehicle rim which is rotatably mounted, via a wheel bearing, on a test bench,
an interior of the vehicle tire being pressurized with a fluid to a fluid pressure by the means for pressurizing the vehicle tire,
the vehicle tire being subjected to the wheel load by the means for applying the wheel load on the vehicle tire,
the vehicle tire being accelerated according to a predetermined speed ramp, the vehicle tire being accelerated by the means for accelerating the vehicle tire from an initial tire rotational speed at a start time of the speed ramp to a final tire rotational speed at an end time of the speed ramp so that the fluid, in accordance with the tire rotational speed, undergoes an oscillation excitement, and the fluid reacts to the oscillation excitement with a pressure oscillation,
the vehicle tire is mounted on one of the test bench rim and a vehicle rim which is rotatably mounted, via the wheel bearing, on the test bench,
the tire rotational speed being detected by the optical, magnetic or electromagnetic means for detecting the tire rotational speed, and forces of the vehicle tire acting on the wheel bearing, due to the pressure oscillation, being continuously detected from the start time to the end time of the speed ramp by the means for the detecting the at least one of the force, the tire oscillation, and the pressure oscillation, and
the test bench further comprising a means for electronic computing, the means for electronic computing being configured to generate a generated data set, or a reference data set, for the force of the vehicle tire over the tire rotational speed and over frequency, whereby a time signal of the speed ramp is submitted to a Fourier transformation.

12 more elements

Dependencies are inferred from the claim text.