Treatment of several common faults of the hottest

2022-08-26
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Abstract: This paper mainly combines the treatment of some common equipment faults of TB880E TBM in the construction of the north entrance of Qinling Tunnel Line 1, and analyzes them according to the system diagram, so as to find out the causes of the faults and provide guidance for the rapid troubleshooting of TB880E TBM in the future construction

as the main driver of TBM at the north entrance of Qinling Mountains, combined with the operation experience of TBM in recent two years and the systematic analysis of equipment, the author summarizes the common faults and treatment methods in the operation process of TBM, so as to provide a basis for the rapid troubleshooting of TBM in the future construction

1 the pressure of the shoring cylinder of the rear outer frame (K2) is not easy to reach the shoring pressure

1.1 fault phenomenon

press the K2 shoring control button, KZ each shoring cylinder (8 groups of shoring, 16 shoring cylinders) extends out under the "differential fast forward" low-pressure shoring working condition, and when the pressure in the large cavity of the cylinder reaches 18.5 MPa, it should be switched to the "work in" high-pressure shoring working condition. But at this time, it was found that the control valve made a "snap" sound, and the pressure in the large chamber of the oil cylinder quickly fell to 0, and then quickly rose to 18.5mpa, and the conversion occurred between 0 and 18.5mpa. Unable to switch to the "work in" working condition, increase the holding pressure to reach the holding state

1.2 treatment method

when the shoring oil cylinder extends under the "differential fast forward" working condition, when the pressure in the large chamber of the oil cylinder reaches 18.5 MPa, stop shoring. At this time, the oil cylinder pressure will slowly drop. When the pressure drops by 0.3-0.4mpa, continue to tighten. In this way, when the pressure of the shoring oil cylinder reaches 18.5mpa, it can smoothly switch to the "working condition", reaching the specified shoring pressure of the shoring oil cylinder above 25.ompa

1.3 cause analysis (see Figure 1 for the hydraulic principle of shoe lifting action)

it can be seen from the PLC program that when the KZ strut button is pressed, the K2 strut oil cylinder is propped out at low pressure under the "differential fast forward" working condition. When the pressure of the outer K strut is greater than 18.5 MPa, the PLC sends a command, p01-148-ylb is powered off, p01-147-y5 is powered on, p01-147-y7 is powered off, and the KZ strut oil cylinder is propped tightly on the tunnel wall under the "working forward" high pressure strut working condition. We know that when the support shoe is supported on the tunnel wall, the large and small cavities of the oil cylinder are connected at this moment, and there is no liquid flow, and its pressure is 18.5mpa of the large cavity. When p01-147-y5 is powered on, the hydraulic lock of the large chamber of the shoe oil cylinder is opened. The small chamber of the oil cylinder is connected with the oil tank, and the large chamber is connected with the "a" port of the cartridge valve. However, due to the "slow opening and slow closing" feature of the logic port of the cartridge valve 213.1, the cartridge valve is not completely closed at this time, and the "a" port and the "B" port are still connected, that is, the large chamber of the oil cylinder is also connected with the oil tank at this time, resulting in the pressure relief of the large chamber and the small chamber at the same time. When pie detects that the pressure is reduced to less than 5.ompa, it can be seen from the program that the PLC command returns to the low-pressure support state, and p01-148-ylb and p01-147-y7 are powered on. This is the "snap" sound in the above phenomenon. The first sound is p01-147-y7 powered on, and the second sound is p01-148-ylb powered on. Under normal circumstances, when the pressure of the outer K support shoe is greater than 18.5mpa, and the support shoe turns into the high-pressure support working condition, its support shoe pressure will also quickly drop to 14.ompa, and then rise to the high-pressure support state of 25.ompa. According to the analysis, this is due to the influence of the opening and closing time of the plug-in alarm. In addition, when a customer asked the company to provide an authoritative test report, it was also found that this phenomenon often occurred when the outer K closed a pair of support shoes and tightened them again. Because after closing a pair of support shoes, the discharge flow of the large chamber of the oil cylinder from the cartridge valve remains unchanged, but the pressure of the support shoes will drop more, so it is easier to unload the pressure to less than 5.ompa within the closing time of the cartridge valve

to avoid this kind of situation, when the characteristics of hydraulic components are not changed, it can be achieved by the operation method, that is, within the complete closing time of the inserting room, the pressure in the large chamber will not be released to less than 5.ompa. Since the time from full opening to full closing of the inserting room cannot be changed, it can be realized that when the inserting room is not fully opened, the supporting shoe oil cylinder can be turned to the high-pressure supporting state, so as to shorten the pressure relief time of the large cavity of the oil cylinder, that is, the supporting shoe oil cylinder can be tightened at low pressure twice. The method is to loosen the support button when the pressure of the large chamber is close to 18.5mpa. At this moment, the cartridge room is slowly closing, the high-pressure support valve is in the upper position, and the low-pressure support valve is in the middle position. The pressure of the oil cylinder will only be reduced due to internal leakage. When the pressure drops by 0.2-0.3mpa, the cartridge room has been closed, and then press the support button. At this time, the cartridge valve slowly opens, but because the support shoe has been supported on the tunnel wall, the pressure of the large chamber will soon reach 18.5 MPa, The PLC controller energizes p01-147-y7 and loses p01-148-ylb, so the cartridge valve starts to close. Due to the "slow opening and slow closing" feature of the logic port of the cartridge valve, the valve closing time is much shorter than that of fully opening and then closing, so that the pressure in the large chamber will not drop to 5.ompa, and then turn to the "Gongjin" high pressure support. In practice, this method is very effective

2 tunneling protection display fault

the propulsion equipment protection measures set by TB880E tunneling machine the following faults often occur in tunneling:

(L) the pressure is lower than the set pressure

(2) the pressure of clamping cylinder is higher than the set pressure

(3) the rear support column cylinder slides down

(4) the cantilever of the rear anchor bolt machine extends

(5) the outer K deflection exceeds the setting requirements

generally, (1), (2) and (3) are easy to find, because it can be seen from the flashing of the indicator light or the pressure gauge, but (4) and (5) are not easy to find, because the sensors used in (4) and (5) are magnetic position sensors due to machine vibration in tunneling, and their indicator lights often flash only once and are not easy to find. Usually, the treatment measure is to fasten the sensor or clean the measured object, so that its position is relatively stable in tunneling and the sensor is not disturbed

3 grease lubrication blockage fault

tb880e roadheader main bearing rotary seal adopts the sealing method of three lip seals plus labyrinth seals, and at the same time, high viscosity grease is evenly injected into the labyrinth seal. The grease is automatically pumped and distributed by the distributor to each oil filling day. The design requires that the time when the grease stops supplying during tunneling should not exceed 3 minutes, otherwise the cutter head stops rotating

3.1 fault phenomenon

the common situation is that after the grease is polluted, the pumping pressure continues to rise, and the general pressure can reach 21.ompa. At this time, the grease lubrication fault is displayed on the fault display in the host operating room

3.2 cause analysis

according to the working principle of grease distribution, any output port of grease distribution cannot work normally after being blocked, resulting in the increase of pumping pressure. The usual search method is to start from the first stage distributor, but it should not be ignored that the three output ports of the first stage distributor have one-way valves. When grease enters the spring cavity, pollutants such as sand are easy to accumulate in the spring, and the one-way valve cannot work normally due to the seizure of the spring. After checking the one-way chamber, open the three output ports one by one and pump grease to check whether the output and pressure are normal. If the distributor is blocked, it should be cleaned or replaced. In practice, it is often the dirt in the one-way valve at the output of the primary distributor that catches the spring, and the piston of the distributor itself is rarely caught

4 the situation of "soft leg of Yang Xingyan, engineer of Zhejiang Jixiang Automobile Research Institute Co., Ltd." or "leg falling" occurs in the rear support

4.1 fault phenomenon

when operating the TBM tunneling machine to change steps, it is necessary to monitor whether the rear support column cylinder pressure and support shoe pressure are normal. If the shoe support indicator light on the operation panel is not on when the shoe support pressure is put down and out, it is called "leg drop"; For example, the pressure of the column cylinder keeps decreasing after the rear support is put down, which is called "soft leg"

4.2 cause analysis

(L) "leg drop" phenomenon: it can be seen from the hydraulic diagram that due to the Y-type intermediate function of the reversing valve, the two pilot oil ports of the hydraulic lock are connected to the oil tank, and there is no possibility of opening it, so the problem should be in the 8.ompa pressure sensor or its current 33500 workers' oil routes around the world. When handling, remove the micro hose connected to the sensor. If there is liquid flow, it means that the pipeline is not blocked, and then connect it firmly with the sensor. In this case, the fault disappears, which means that the sensor connector is not opened; If the fault still exists, it is a sensor fault, and the sensor should be replaced. In practice, it is usually caused by a slight loosening of the connector between the sensor and the micro hose and the failure to open the check valve. It may be due to the vibration of the machine and the short one-way jacking rod on the micro hose, resulting in a slight loosening, that is, the failure to open the check valve and the loss of signal of the pressure sensor

(2) "soft leg" phenomenon: it can be seen from the hydraulic diagram of the rear support that if it is not the manufacturer, the price is relatively higher than the manufacturer's price. When the column cylinder extends until the set pressure, due to the locking effect of the hydraulic lock and the Y-shaped intermediate function of the reversing valve, the pilot oil circuit of the hydraulic lock is at zero pressure and the hydraulic lock cannot be opened, and the rapid pressure reduction cannot be formed due to the internal leakage of the cylinder, Therefore, the cause of internal leakage of oil cylinder can also be eliminated. When handling, first eliminate the cause of the hydraulic lock: block the oil inlet o of the hydraulic lock. If the fault is still found, find another cause. It can be seen from the hydraulic diagram that there is also an oil outlet on the hydraulic lock of the large chamber of the column cylinder, that is, the pressure tap. Plug the pressure tap, and then extend the column cylinder. It is found that the fault disappears. It can be seen that there is leakage on the pressure measuring oil circuit. The analysis shows that since the pressure measuring oil pipe led out from the hydraulic lock on site is 12m long, it is connected to the bundle hose joint of the central platform of the main engine and then connected to the operation room, and there are many oil pipes in the central platform area, with serious oil dirt accumulation; In addition, the pressure measuring oil pipe is very small, surrounded by many large oil pipes in the middle platform, which is easy to be damaged; The oil leakage is small and difficult to find; Therefore, the phenomenon of "soft legs" in actual operation is largely derived from this

5 the temperature of the water-cooling device is too high

tb880e roadheader's water-cooling device adopts the solenoid water valve to control the water circuit switch, including the lubricating oil cooling system, the motor gearbox cooling system, the main pump station oil cooling system, and the 3 belt conveyor pump station cooling system. The common situation is that after the service life of TBM is as long as one year, it will appear intermittently that after some systems are opened in the water-cooled electromagnetic room, the cooling effect is not obvious, and even after cleaning the cooling water jacket, the effect is still not ideal. The analysis shows that the water quality is relatively hard, which causes the fouling in the electromagnetic water spring cavity and makes the spring work abnormally. The temporary treatment measure in tunneling is to knock the water spring cavity, and the effect is obvious

summing up the above five common faults, the author believes that when operators find problems in tunneling, they should first be clear-minded, avoid complicating the problems, and should hand in the simplest place, step by step, so as to leave valuable tunneling time for TBM. (end)

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