VIBRATION SYSTEM

vibration on concrete block making machines

Shock vibration is the generally accepted method for compaction in the industrial-scale production of small precast concrete elements. With this very effective and highly productive method, however, problems arise with optimising the machine settings, achieving reproducible product quality, wear and, not least, high noise emissions. A new method, which uses harmonic vibration, completely dispenses with knocking bars and replaces the missing acceleration peaks produced by the jarring blows with correspondingly higher forces.

Harmonic vibration in concrete block machines produces selected sinusoidal oscillations with high acceleration amplitudes in all working dimensions. Harmonic oscillations for concrete compaction are sufficiently well understood; the challenge is in the technical implementation of such an oscillation regime which is equal to or exceeds the compaction effect produced by shock vibration.

The motive for using harmonic vibration on concrete block makers is that the harmonic oscillations produce less noise on the machine and facilitate simple and robust machine adjust-ment. Solutions brought about by hydraulic excitation repre-sented the first milestone [1]. Now, an economical approach using electric motors has also been successful and has been proved effective for more than a year in practice.

Technological concept and layout of vibration

The essential differences between these and shock-vibration machines are that the table and mould permanently braced, there are no knocking bars and the table vibrators produce higher exciter forces.

In the simplest case, the vibratory system can be regarded as a dual-mass system. Many different parameter studies have led to a description of masses, spring stiffnesses and forces.

The necessary total active force was determined to be more than 600 kN and is therefore many times more than that of the usual exciter systems of shock vibration machines.







VIBRATION SYSTEM vibration on concrete block making machines Shock vibration is the generally accepted method for compaction in the industrial-scale production of small precast concrete elements. With this very effective and highly productive method, however, problems arise with optimising the machine settings, achieving reproducible product quality, wear and, not least, high noise emissions. A new method, which uses harmonic vibration, completely dispenses with knocking bars and replaces the missing acceleration peaks produced by the jarring blows with correspondingly higher forces. Harmonic vibration in concrete block machines produces selected sinusoidal oscillations with high acceleration amplitudes in all working dimensions. Harmonic oscillations for concrete compaction are sufficiently well understood; the challenge is in the technical implementation of such an oscillation regime which is equal to or exceeds the compaction effect produced by shock vibration. The motive for using harmonic vibration on concrete block makers is that the harmonic oscillations produce less noise on the machine and facilitate simple and robust machine adjust-ment. Solutions brought about by hydraulic excitation repre-sented the first milestone [1]. Now, an economical approach using electric motors has also been successful and has been proved effective for more than a year in practice. Technological concept and layout of vibration The essential differences between these and shock-vibration machines are that the table and mould permanently braced, there are no knocking bars and the table vibrators produce higher exciter forces. In the simplest case, the vibratory system can be regarded as a dual-mass system. Many different parameter studies have led to a description of masses, spring stiffnesses and forces. The necessary total active force was determined to be more than 600 kN and is therefore many times more than that of the usual exciter systems of shock vibration machines.
SITE MAP