Abstract
A hydraulic silencer called a “resonator hose”, that places flexible metal tubes (called a “tuning cable”) inside a section of reinforced hose coaxially, is commonly used in automotive power steering hydraulic lines to suppress transmission of pump-induced pressure pulsation and thus reduce fluidborne noise radiated into the passenger compartment. However, finding the optimum design configuration for the resonator hose has been a matter of experience-based trial and error because an accurate mathematical model for pulsation attenuation characteristics of a resonator hose had not been established. This paper presents an optimum design method for a resonator hose, taking into consideration every key circuit factors in a real power steering system. First, a method of determining experimentally the viscoelastic properties of the hose wall from measured transmission loss characteristics, which is necessary for establishing a mathematical model for the resonator hose, is proposed and discussed with estimated results. Next, a successful mathematical means (optimum design method) is outlined for sizing the desired variables (lengths of tuning cables and hose) so that the performance function designated in terms of pressure pulsations is minimized under the designated constraint conditions Calculated results of attenuation characteristics of eight kinds of optimally designed resonator hoses all agree well with experimental results.
