Rock drilling rig classification Rock drilling rig fault analysis
Introduction
It is mainly composed of a rock drill, a drilling arm (the support, positioning and propulsion mechanism of the rock drill), a steel frame, a traveling mechanism and other necessary ancillary equipment, as well as equipment added according to project needs. When drilling and blasting is used to excavate tunnels, it provides favorable conditions for the use of rock drilling rigs. The combination of rock drilling rigs and ballast loading equipment can speed up construction, increase labor productivity, and improve working conditions.
Classification of rock drilling rigs
The traveling mechanisms of the rigs include track, crawler and spoke type, and digging type. Domestic rock drilling rigs are mostly of the track and tire type.
Rail-type drilling rig
The vehicle body is generally a gantry type, so it is often called a gantry-type rock drilling rig. There are 2～3 working platforms on the upper part, which can install multiple units (up to 21Taiwan) rock drill; the lower part can pass ballast loaders, transport vehicles and other machinery. This kind of trolley has multiple functions such as drilling, charging, supporting, and measuring. It was developed to meet the needs of large-section tunnel construction and at the same time overcome the shortcomings of low drilling efficiency of hand-held rock drills. It is popularized and applied in the construction of railway tunnels and hydraulic tunnels. Install several drill arms on the vehicle body( to install the rock drill, usually1～ 4 Taiwan) self-propelled rock drilling machinery and equipment. The drill arm can be turned at will, and the rock drill can be moved to any position and direction on the working surface to drill holes(holes). Drilling parameters are more accurate, drilling efficiency is high, and the working environment is greatly improved.
The power of the trolley is divided into mechanical type and hydraulic type. The latter is widely used and has a high degree of automation. The entire drilling (hole )The program is controlled by a computer. In the development process, the ladder-frame rock drilling rig of pneumatic rock drills was initially used, and gradually hydraulic rock drilling rigs were used.The machine’s gantry rock drilling rig was replaced.
Tire track
Mainly driven by diesel engine, installed 2～6 high-speed rock drills, with small turning radius, flexible maneuverability and high efficiency. They are generally used for tunnel excavation in mines, can also be used Excavation of tunnels and underground projects.
Application
The four-arm hydraulic rock drilling rig used in the construction of the Dayaoshan double-track tunnel of the Beijing-Guangzhou Railway in China,It is a special truck driven by diesel and controlled by pneumatic hydraulic pressure,The total length of the trolley15meters, height4.3meters, width3.5meters, weight42tons, equipped with hydraulic rock drills4 (see picture), the drilling speed is generally higher than that of pneumatic rock drills50～100%, the energy consumption is one-third of that of wind, and it can reduce noise; it can also be adjusted according to the surrounding area. Rock hardness adjusts oil volume, pressure and piston stroke to improve rock drilling efficiency. With the development of shotcrete anchor support technology, the application scope of full-section one-time excavation has been expanded, providing favorable conditions for the use of rock drilling rigs. The advent of new hydraulic rock drills and their use on rock drilling rigs will make the entire Tunnel and underground projects have shifted to a new stage of fully hydraulic large-scale mechanized construction.
Fault analysis
1, early failure
Preliminary failures, that is, failures caused by poor design, etc., are mainly reflected in the following aspects:
1. 1The new car cannot be located
The new car has just arrived When the drilling boom end jack leg is controlled, the leftThe end is linked transversely and longitudinally, and the right end is linked transversely and longitudinally. The linked outrigger cylinders extend and retract at the same time. In this way, when the longitudinal outriggers touch the ground during positioning, the system pressure oil is released and returned to the oil through the safety valve, and the positioning operation is forced to stop. By changing the linkage mode to: horizontal linkage of the left and right ends and longitudinal linkage of the left and right ends, or changing the linkage control to independent control, the rock drilling rig can be positioned.
1. 2The safety valve is not sensitive enough, causing malfunctions
The jack legs at the drill arm end of the positioning system can be extended longitudinally or laterally. The correct positioning method is: before drilling, first extend horizontally and then extend longitudinally. After drilling is completed, first retract longitudinally and then laterally. Back. If the operation sequence is wrong, due to the low sensitivity of the safety valve on which the positioning system relies, when the positioning pressure increases suddenly, faults such as “positioning pipe bursts and oil leakage” will occur in the early stages of use, which is wasteful and delays tunnel operation time. .
1. 3Faults caused by misoperation
Although The positioning pump has stopped working, but the positioning system still has pressure. If the control handle is accidentally touched or misoperated, it may cause malfunction or even cause an accident. As long as the hydraulic system is properly improved, misoperation overload protection can be achieved, oil can be drained before the pipe bursts, and the positioning system can be protected. It can also improve the reliability of the positioning system when the drilling rig is drilling, and eliminate the risk of accidents.
1. 4Faults caused by imperfect pressure oil filter system
Because the principle of NH178 rock drilling rig’s pressure oil circuit filtration system is that when the filter is clogged, the pressure oil will not return to the oil tank, but will continue to enter the system. This can easily cause the system to go out of control. This is the reason why the propulsion cylinder goes out of control often in the early stages of use. Improving the pressure oil line filtration system can reduce system out-of-control failures.
2、Usability failure
Usability failureFailures are caused by unfamiliarity with the working principle of the equipment during use, improper use, and the equipment often working in a sick state, causing the equipment to lose many of its due safety protection measures for a long time, and faults caused by imperfect intelligent control functions. After a fault occurs, it will cause great damage to the equipment. Common usability faults include:
2． 1Failure caused by waterway
Water storage If the water source such as the pool is not clean, the water filter in the machine will be clogged and damaged. If it is not checked and replaced in time, the sand and gravel entering will cause the booster water pump blades to break or accelerate wear. In this way, the working water pressure will drop and the water control air valve will open. If it is not turned on, the air circuit control part of the entire vehicle will not work. If you want to continue working, you must change the air path and unplug the N8 air pipe so that the air path is not controlled by water pressure and the trolley works with low water pressure. Since the water control air valve does not operate, drilling cannot be stopped when the water is cut off. Jamming will inevitably occur, the rotating motor will be blocked, and the oil pressure will rise sharply. At this time, if the anti-jamming valve does not operate, the pressure will not be released and the oil will return, which will definitely occur. The drill pipe bit is stuck, the hydraulic oil pipe is broken, the system is leaking oil or the oil temperature is rising. In the water circuit, poor circulation of the hydraulic oil radiator can also cause high oil temperature.
2． 2Fault caused by damaged ring of pressure gauge
Nine-way pressure gauges play a role in monitoring the anti-jamming pressure, positioning pressure, and propulsion return pressure of the three arms respectively. The three impact pressure gauges can monitor the impact pressure of the three arms. If these pressure gauges are damaged and are not replaced in time, , the following problems will occur: (1) Due to wear of hydraulic components and leakage of pressure oil, the hydraulic system loses control and cannot work normally; (2) or blindly increase the pressure for work, oil pipe bursts and oil leaks will often occur. It was found at the scene that: the propulsion pressure of the three arms is 1.2-1.5 times of the normal pressure; the propulsion and return pressure of the three arms is 2-2.5 times; the impact pressure of the three arms is also high; the anti-jamming drill fails to work in coordination, does not return when initially stuck, often bursts of pipes, and leaks oil. These are pressure gauges After damage, increase the pressure and work reluctantly to cause the failure. At the same time, this is also the reason for excessive consumption of drill bits and drill pipes.One of the reasons.
2． 3Oil return system failure
Oil return The filter plays a role in filtering impurities and dissipating heat in the oil return system. The working status of the oil return filter is transmitted to the alarm circuit of the distribution cabinet through the sensor. When the oil return warning light is on, it prompts to replace the oil return filter. If the sensor is damaged and not replaced in time, the working condition of the oil return filter will deteriorate. First, blockage causes increased oil return pressure and poor heat dissipation. If the oil return filter is not replaced, it will cause wear and leakage of hydraulic components and burst hydraulic pipelines.
2. 4Failure caused by circuit
Rock drilling The trolley uses high-voltage power supply and low-voltage control. If the circuit fails, it will lose balance if it works reluctantly. The heating of electrical components indirectly affects the temperature of the hydraulic oil. If the charger is damaged and not repaired, it will cause the control transformer to heat up. If the pulse generator is damaged, the lubricating oil will not work and the rock drill will wear out, causing Oil leakage and temperature rise.
3、Hydraulic system failure caused by improper selection of oil
Hydraulic oil, hydraulic oil pipe In the use of rock drilling rigs, it has a great impact on the performance of rock drilling rigs. If qualified hydraulic oil is not selected according to the label and characteristics, the hydraulic oil will have high mechanical impurity content, moisture, and poor wear resistance; if the hydraulic oil pipe selected is a counterfeit product, especially an overstocked product that has exceeded the shelf life, use The inner layer will fall off, some joints are roughened, and debris will enter the hydraulic system; these will cause the oil circuit to be blocked, causing early wear of the cylinder and motor, blockage or wear of the hydraulic valve, and ultimately leading to internal leakage and external leakage. If the pressure is insufficient and the control fails, the only way to work is to increase the pressure and force drilling, which creates hidden dangers for the hydraulic system.
At the same time, the inherent impurities brought into the system during assembly, the oxides produced during use, and the dust, water, air and other pollutants that invade from the outside during maintenance and assembly will directly or indirectly cause various problems. Such failures will be reduced and avoided as long as the pollution control of the system is strengthened and the system is kept clean.
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