System Design And Performance Analysis For The Vivration Valve With Independment Adjustable Amplitude And Frequency

The traditional clay brick is gradually replaced by concrete block which is energy-saving and environmental friendly, with the rapid economic development and higher environmental protection. Today, our country’s construction industry is developing rapidly, the requirements on strength of block is higher and higher. The strength of concrete block is depended on the block density and uniformity to a great extent. The research data has showed that when the density of block increased1%, the compressive strength can be increased by about4%. The block density and uniformity is depended on the performance of the vibration system of block forming machine. Different gradation, different materials require different vibration frequency and different amplitude. But the current mechanical or hydraulic vibration exciter used on block forming machine can not satisfy the independent control of frequency and amplitude. The mechanical vibration exciter exists many drawbacks such as:the vibration mass is larger; the frequency is lower and the influence on the lifetime of bears and mechanism is bigger. The higher the frequency, the smaller the amplitude of the hydraulic vibration exciter. To improve the amplitude, you must increase the system supply pressure. And the system pressure excites hysteresis because of the accumulator. It is hard to meet the requirement of a higher frequency and a high amplitude at the same time.The amplitude of hydraulic vibration exciter is not only concerned with supply pressure but also concerned with the opening of the valve. For this reason, a new hydraulic vibration system controlled by a two-dimension excitation valve is proposed. The valve can change the area of passage by controlling the rotational motion and the axial displacement of the valve core, to realize the independent control of the frequency and amplitude. The principle of the two-dimension excitation valve is expounded and the structure is designed, especially, the key position of the valve is particularly designed and calculated.The mathematical model of the new vibration valve is established, the dynamic property is simulated in the Matlab environment, and the simulation curves are plotted. The simulation result shows that in the case of a constant supply pressure, when the amplitude decreased because of frequency increase, we can increase the amplitude by increasing the axial opening. When the change of vibration mass leads to the change of amplitude, we also can adjust the amplitude by adjusting the axial opening. So, this vibration system can easily achieve the independent control of vibration frequency and amplitude, to meet the requirements of frequency and amplitude of different gradation with different materials, to get the best vibration effect of materials, to increase the density and uniformity of the block, to get the high quality block. It is practicable to apply this system to block forming machine.The innovation of the paper is a new hydraulic vibration system controlled by a two-dimension excitation valve is proposed. The valve can change the area of passage by controlling the rotational motion and the axial displacement of the valve core, to realize the independent control of the frequency and amplitude.