1. Working principle
The working principle of the pipe jacking machine is to push the tool pipe or roadheader from the working well through the soil layer to the receiving well with the help of the thrust of the main jacking cylinder and the relay room between the pipelines. At the same time, the pipeline following the tool pipe or the boring machine is buried between the two wells, so as to realize the non-excavation laying of the underground pipeline.
2. Matters needing attention
Before construction, the pipe jacking equipment must be installed at the work site first, and the track should be laid on the installation site according to the relevant requirements to place the rotary excavation system; then the crane should be arranged to lift the system to the laid track; finally, the cables and wires should be installed. If there is a sensor, install the sensing device.
1. Disassembly
The purpose of disassembling and assembling the pipe jacking machine is mainly for transition, maintenance and preparation for new construction tasks after shutdown. During the disassembly and assembly process of the pipe jacking machine, the disassembly and assembly work should be regulated according to the assembly and disassembly requirements. When disassembling, first remove the wiring of the measuring instrument and the assembled parts, and then remove the main cable of the rotary excavation system and easily damaged sensors (such as alarm and measurement positioning sensors, etc.). After the above disassembly work is completed, the rotary excavation system should be hoisted out of the foundation pit as a whole and transported to the maintenance site. The disassembly and assembly of other working systems of the pipe jacking machine should be carried out in accordance with the disassembly and assembly requirements of different systems such as: main jacking system, grouting system, electrical system, etc.
2. Replace the cutting head
When the pipe jacking equipment disassembles the rotary excavation system, the cutting head should be carefully inspected every time it is disassembled, and the cutting head with serious wear and tear should be replaced. The cutting head is mainly composed of the tip and the handle. The material of the handle is mostly heat-treated medium carbon steel, and the material of the tip is mostly hard alloy or tool steel. In terms of shape, the cutting head is divided into rake angle , Back angle two.
3. Maintenance of cutting cutter head
Every time the rotary excavation system is disassembled or installed, the soil and sand seals of the cutting cutter head must be inspected, maintained and repaired, and the bearings should be lubricated. to ensure smooth operation of the equipment. The maintenance of the cutting disc should be carried out in two aspects:
① Check the sand and gravel seals to see if there are any loopholes, and if there are loopholes, they should be dealt with in time;
②Apply lubricating fluid to all bearings one by one.
4. Torque detection of cutting cutter head
After the overhaul or technical transformation of the rotary excavation system, the torque of the cutting cutter should be tested. The torque of the cutting cutterhead is determined according to the geological conditions and factors such as the type, construction and diameter of the rotary excavation system. Generally, the following factors need to be considered: the cutting resistance moment of cutting soil, gravel, etc.; the friction resistance moment between the cutting cutter head and the soil; resulting resistance torque, etc.