摘要 |
In a method for compacting a granular, loosely coherent mass, such as moist mortar, to obtain end products such as paving stones, kerbstones and the like, an installation is used which includes a vibrating table, a mold for the mass to be compacted, a stamp for pressing the mass into the mold, a hydraulic exciter and a hydraulic pressure element respectively connected to the vibrating table and the stamp, and a driver and a controller for controlling the exciter and pressure elements. The method includes the steps of selecting a frequency range with a lower value and an upper value for the excitation frequency, and controlling the excitation frequency so that it passes through at least part of the frequency range and so that it reaches the natural frequency of the hydraulic-mechanical mass spring system formed by the movable part of the exciter, the vibrating table, the mold and the mass to be compacted, as well as the compressible hydraulic medium present between the movable part of the exciter and the driver concerned.
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