摘要:
A device for reducing certain sound ranges of tire/road surface noise of a motor vehicle includes sound absorbers in the form of resonators positioned at the inner wall of a wheel well of the vehicle in the area of sound projection of the tire/road surface noise. The device has an electronic control device for receiving a signal preferably derived from an ABS system in the form of the wheel rpm. The control device adjusts the resonators according to the number of tread blocks of the tire, the sound emission characteristics, and the wheel rpm. In another embodiment the electronic control device is supplied with signals received from a sound receiver that records the course over time of the sound pressure. The control device adjusts the resonators such that the measured sound pressure signal is minimized. In another alternative the device has a data processing unit including an electronic control device. The control device is supplied with a signal from sound receiving devices that record the course over time of the sound pressure. The data processing unit together with an adjusting device adjusts the resonators such that the measured sound pressure signal for selected frequency ranges is minimized.
摘要:
A vehicle tire having a profiled tread on the periphery of which are arranged pitches of at least two different lengths. In an axial direction, the tread is divided into several parts, with the successive pitch length in a given axial part forming a pitch sequence. To further reduce radial force fluctuations that induce vibrations by the transmission of noise into wheel suspension and body parts, the phase offset between the pitch sequences of the various tread parts is dimensioned such that the distance between the absolute extremes of the summation of weighted representations of a given function is minimal or at most 25% greater than this minimum. Each of the tread parts have associated therewith a function that is the successive plotting of successive pitch lengths of the pertaining tread part on the abscissa while marking off the respective pitch length, starting from the abscissa, onto the ordinate. From each of these functions a "representation" is determined that is what remains after elimination of all harmonic parts of greater than the x order, with "x" being an integer between 8 and 14. To determine this remainder, the function is first harmonically analyzed from the first to the x order, and from this information, including the phase information, the representation is generated by synthesis.
摘要:
A vehicle wheel has a wheel rim with a radially inwardly positioned mounting surface and rim flanges connected axially to opposite ends of the the mounting surface. A pneumatic vehicle tire with a carcass including at least one carcass ply is provided. The pneumatic vehicle tire has a tread and two sidewalls. The pneumatic vehicle tire is mounted on the inner mounting surface of the wheel rim so as to substantially enclose the mounting surface of the wheel rim. The rim flanges have a radially outwardly projecting end portion serving as axial contact surfaces for a respective one of the sidewalls.