The Rock Breaking Test Bench Electro-Hydraulic Control System Of Tunnel Boring Machine

Tunnel boring machine is a large construction machinery applied in construction engineering, such as railways, highways, municipal, water conservancies and hydropower tunnels. The cutters, as key component in the excavation, are mainly used to break and strip the rock surface. In the process of tunnel boring, the complex geological conditions make the cutters cutting conditions and stress state extremely more complex, while their state of breaking rocks directly affects the boring efficiency. Therefore, the research on the crushing mechanism between cutters and rocks has great significance in optimizing the cutters design and improving productivity.In this thesis, the rock breaking test bench of tunnel boring machine is regarded as the research subject. This bench is composed of press loading system, a rotary cutting system and a linear cutting system. The press loading system is used to achieve the function of driving the cutters forward. The rotary cutting system is used to achieve the rotary movements of the rock sample box, and the linear cutting system is used to implement horizontal movements of the rock sample box. According to the experimental requirements, the rock breaking test bench control system of tunnel boring machine with monitoring, data acquisition and control functions has been built, and the requirements of this test bench are all satisfied. The primary contents in this thesis are as follows:1. According to the experiment outline requirements of the rock breaking test bench of tunnel boring machine, the electro-hydraulic control system of the test bench is designed and the power unit of the test bench is analyzed. The test bench can accomplish rock breaking cutter tests with the cutters installed in different radius and in different space, and under different rock compressive strength.2. The control system with a host computer and a lower computer is set up. A touch screen computer with embedded configuration software is used as host computer, and a PLC is used as the lower computer. The corresponding control program is compiled, and the HMI is developed by using the configuration software. The functions such as state monitoring, data acquisition and corresponding actuator coordinated control in the process of test running are realized.3. According to the two working modes in the press loading system of the test bench, the constant depth cutting mode is realized by the entrance throttle governing system and the hydraulic lock. The constant pressure load control working mode is realized by the real-time control for the proportional relief valve based on PID control algorithm. The mathematical model of the electro-hydraulic control system in the constant pressure load working mode is established. Furthermore, the control system is simulated and analyzed by using MATLAB software in the sample box under the conditions of constant speed and variable speed, and finally its effectiveness is verified.