Research On Buffer Characteristics Of The Reversing System Of S Tube Valve For Concrete Pump

Nowadays, concrete pump plays a more and more important role in modern architecture construction. Concrete pumping completely changed the concrete construction site look. Reversing of concrete pump, which is realized by the coordination of the to-and-fro movements of a piston and the reversing distributing valve, is a crucial link when working. The coordination of the pumping system and the reversing system is the prerequisite for continuous pumping and pouring of concrete. Good and reliable reversing property can ensure the well pumping, which is highly efficient, has small impact and low noise. Since the reversing system has to realize the reverse of the S tube valve in very short time, hydraulic impact is very common in reversing. Researches on the dynamic characteristic of the system have great practical significance in Engineering to reduce the impact and vibration of concrete pump reversing system and improve the performance and reliability of concrete pump. In the paper, main researches contain as follows:1. Flow state of the pumping concrete in conveying pipe is analyzed based on the principle of rheology. The theory, the flow of the concrete in conveying pipe is similar to Bingham body in present pumping conditions, is pointed out in this paper. And based on that, the rheological equation and pumping pressure of the pumping concrete is concluded. Swing resistance moment when reversing of the S tube valve is analyzed comprehensively.2. The kinematic analysis is done and kinematic equations of S tube valve of swing mechanism are concluded, according to its simplified model. Buffering properties of buffer devices with constant throttle and variable throttle inside the cylinder is compared.3. The buffer process is divided into three parts:contraction of local pressure loss, sharp edge throttling and throttle aperture. And equations of each part are built.4. According to hydraulic system principle of the S pipe distribution valve and kinematic model of the swing mechanism, corresponding Simulink model is built by using the Power Bond Graph and the Matlab software. Parameters of buffer plunger in swing cylinder, parameters of accumulator, and the influence on the dynamic characteristics and the buffering properties of reversing system of the S tube valve by load resistance are analyzed.5. A reversing system experimental platform of S pipe valve of concrete pump is built. In a company’s trailer pump, its dynamic characteristics of reversing system and buffer performance of swing cylinder are analyzed through the research of pump-water test, which validates the rationality of the construction of buffer device of swing cylinder and the correctness of the models.