Jumbo
close Jumbo is also called drilling jumbo. It is a kind of rock drilling equipment for tunnel and underground engineering construction by drilling and blasting method. It can move and support multiple rock drills to drill at the same time. It is mainly composed of rock drill, drill arm (support, positioning and propulsion mechanism of rock drill), frame of steel structure, running mechanism and other necessary auxiliary equipment, as well as equipment added as required by the project. The combination of drilling jumbo and ballast loading equipment can speed up construction, improve labor productivity and improve working conditions. Trolley traveling mechanism includes track, crawler and tire. There are many domestic rock drilling jumbos of track and tire type. The body of rail mounted jumbo is generally gantry type, so it is often called gantry type rock drilling jumbo. The upper part is equipped with 2~3 layers of working platform, which can install multiple (up to 21) rock drills; The lower part can pass the ballast loader, transport vehicle and other machines and tools. This kind of trolley has many functions such as drilling, charging, supporting and measuring. It is developed to meet the needs of large section tunnel construction and overcome the shortcomings of low drilling efficiency of hand-held rock drill. It is widely used in railway tunnel and hydraulic tunnel construction. A self-propelled rock drilling machine equipped with several drill arms (usually 1~4) on the car body. The drill boom can rotate freely, and the drill can be operated to drill holes (holes) at any position and direction on the working face. The drilling parameters are more accurate, the drilling efficiency is high, and the working environment is greatly improved. Trolley power is divided into mechanical type and hydraulic type. The latter is widely used with high degree of automation. The whole drilling (hole) program is controlled by computer. In the development process, the ladder type rock drilling jumbo with pneumatic rock drill was initially used, and gradually replaced by the gantry type rock drilling jumbo with hydraulic rock drill. The tire type and crawler type rock drilling jumbo is mainly driven by diesel engine, and 2~6 high-speed rock drills are installed. The car body has small turning radius, flexibility, and high efficiency. It is generally used for mining drift excavation, as well as tunnel and underground engineering excavation. During the construction of Dayaoshan double track tunnel of Beijing Guangzhou Railway in China, the four arm hydraulic drilling jumbo is a diesel driven special truck, which is pneumatically controlled and hydraulically operated. The jumbo is 15 meters long, 4.3 meters high, 3.5 meters wide, and 42 tons in weight. It is equipped with four hydraulic rock drills (see figure). Its drilling speed is generally 50 to 100% higher than that of pneumatic ones, and its energy consumption is one-third of that of pneumatic ones, which can reduce noise; It can also adjust the oil volume, pressure and piston stroke according to the hardness of surrounding rock to improve the drilling efficiency. With the development of shotcrete anchor support technology, the application scope of full face one-time excavation has been expanded, providing favorable conditions for the use of rock drilling jumbo. The advent of a new type of hydraulic rock drill and its use on the rock drilling jumbo will turn the whole tunnel and underground works to a new stage of full hydraulic large-scale mechanized construction.