What is the role of shield machine tools
Fishtail knifeThe whole section cutter cutting soil, arranged in a different position on the cutting knife, knife disc from Zhouzhi center, full moon movement decreases, center theory can be regarded as zero. In other words, the length of the cutting soil in the sealed cabin is gradually reduced from the outside to the inside.
Cutting knifeThe cutting tool is the main cutting tool of the cutting face of the shield machine. The general shape of the cutter is shown in figure 15. Under normal circumstances, the beta (front angle) and alpha (back) values vary with the characteristics of the cutting layer, the value range of 5 to 20 degrees, sticky soilThe layer is slightly larger and the sandy cobble stratum is small. For example, the characteristics of the formation of Beijing, beta (front angle) and alpha (back) value recommended 15 degrees.
Profiling cutterThe shield machine is usually designed with two profiling tools (one spare), which are arranged at both ends of the spokes. During the construction, according to the requirements of over excavation and over excavation, the cutter can be extended out and retracted from the two ends of the spoke, so as to achieve the purpose of imitating cutting. The maximum value of the profiling knife is between 80 and 130mm. The shield machine advancing, on the curve turning or correction, by copying the overbreak cutting soil to create the necessary space, ensure the shield machine in the excavation on the surrounding soil, less interference under the condition of small curve and promote smooth turning and rectification, and the shield machine set profiling knife.
Advance knife (also known as the first knife)As the name suggests, the first knife is the cutting tool. In the design of the advanced tool, the main consideration is the combination of cutting tools. When cutting the soil, the cutting tool cuts the soil before cutting the cutting soil, cutting the soil into pieces, and creating a good cutting condition for the cutting tool. According to its function and purpose, the advanced cutter section is generally smaller than the cutting knife section. The use of advanced tools, generally can significantly increase the flow of cutting soil, greatly reducing the cutting tool torque, improve the efficiency of cutting tools, cutting tool wear. The effect is very obvious in loose strata, especially in sandy cobble stratum.
