Abstract: With the acceleration of urbanization, the ascending ladder ladder fire truck is widely used in high-rise building fire fighting. Ascending ladder ladder fire truck structure is relatively complex and has very high safety requirements. Therefore, this article takes the common faults of climbing ladder ladder fire trucks as the research object, firstly sums up the overall structure of the climbing ladder ladder fire truck, and then analyzes the main faults of the climbing ladder ladder fire truck from the mechanical structure, water system, hydraulic system, electrical system and other aspects; The instruction manual of the climbing ladder ladder fire truck proposes troubleshooting and maintenance measures.
Keywords: climbing ladder ladder fire truck; fault; elimination; maintenance
With the rapid advancement of urbanization and the constant construction of high-rise buildings and super-tall buildings, the fire suppression of high-rise buildings has become a difficult point in the current fire suppression. As a weapon of high-rise building fire fighting, the climbing ladder ladder fire truck is also increasingly receiving The attention of fire departments at all levels. As a fire-fighting equipment that can be used both for extinguishing fires and for saving people at high altitude , the climbing ladder ladder fire truck has played an active role in fighting fires in high-rise buildings. However, due to the relatively complicated structure of the climbing ladder ladder fire truck, the safety requirements are relatively high, and if it is used improperly , can easily cause accidents. In view of this, this article studies the troubleshooting and maintenance of the common faults of the ascending ladder ladder fire truck, in order to help the safety application of the climbing ladder ladder fire truck.
1 Ascend ladder ladder fire truck overall structure
Howe DG32H/Benz 32J Platform Fire Truck
The climbing ladder ladder fire truck is an integrated fire engine that can realize high-altitude fire fighting, high-altitude fire extinguishing, rescue and rescue, and high-altitude engineering operations. It is a type of high-lift fire truck. The climbing ladder ladder fire truck will increase the fire extinguishing , emergency rescue and disaster relief operation scope to tens of meters in vertical height, which can make it easier for firefighters to access high-rise buildings, extinguish fire extinguishing, carry out rescue work, and rescue materials. Therefore, the role of fire fighting, rescue, and relief supplies for climbing ladder ladder fire trucks is particularly important for high-rise buildings. With the development of China's economic construction and the increase of high-rise buildings, the situation of urban firefighting is becoming increasingly severe. Because of the advantages of climbing fire ladders, it will certainly play an increasingly important role in urban firefighting.
The climbing ladder ladder fire truck is mainly composed of a chassis, a turntable, a boom, a manned platform, and a fire extinguishing device. The specific structure is shown in Figure 1 .
Figure 1-1 Ascending ladder ladder fire truck structure
Specifically, the climbing ladder ladder fire truck is mainly composed of the following parts:
(1) Chassis. The chassis is the skeleton of the ascending ladder ladder fire truck, and is also the driving device of the climbing ladder ladder fire truck. The chassis of the climb ladder ladder fire truck mostly uses the automobile chassis, which is flexible, has a small turning radius, and has good passability. The reformed chassis of the special-purpose vehicle is specially designed and modified according to the requirements of the climbing ladder ladder fire truck. The wheelbase is long and the frame rigidity is good. The use of a front-hanging sunken cab can satisfy the restrictions on the height of the entire vehicle for road transport and allow space for the boom arrangement.
(2) Sub-frames and legs. The subframe is an additional frame mounted on the chassis frame of the climbing ladder fire truck, and is the main bearing component of the climbing ladder fire truck. The sub-frame can transfer the working load, automatic load and additional load of the climbing ladder ladder fire truck to the ground through the legs, and ensure the balance and reliability of the entire vehicle.
(3) Rotary platform. The slewing platform is composed of a hydraulic motor, a rotary speed reducer, and a slewing pinion. It is used to mount the boom, luffing mechanism, swing mechanism, on-board control unit and on-board hydraulic unit rack to connect and disengage the car. On board hydraulic system, luffing system, boom system and slewing system. The slewing platform can well control the left and right rotation of the ladder system of the ladder ladder.
(4) Boom system. The boom is the most important load-bearing component of the ladder ladder fire truck, and the work platform is lifted by the boom extension and amplitude change action. The personnel are transported to the designated working height and completed by the telescopic boom and boom condition. Ascending ladder ladder fire truck in the form of folding arms, telescopic arms, combined arms.
(5) Leveling system. When the climbing ladder ladder fire truck is working, the working platform is not in the horizontal state but has a certain inclination angle. At this time, the leveling mechanism of the climbing ladder ladder fire truck has a function, so that the climbing ladder ladder fire truck will produce the opposite rotation in real time. In order to achieve the working platform is in a horizontal state.
2 Common failure analysis of climbing ladder fire truck
In general, the technology and performance of the climbing ladder fire truck are reliable in actual operations, and the failure rate is relatively small. However, if the operation, maintenance and maintenance are not properly performed, various failures will occur, which will affect the normal use in actual combat.
2 . 1 mechanical structure failure
The mechanical failure of the climbing ladder fire truck mainly refers to the failure of the components of the fire truck. Mainly manifested as no action on the car, get off, slewing motion failure does not move, the amplitude of jitter crawling, working platform operation failure. The failure of the mechanical structure of the climbing ladder ladder fire truck and its causes are shown in Table 1 .
Table 1 Failure Analysis of the Mechanical Structure of the Ascending Rung Ladder Fire Truck
2 . 2 water system failure
It consists of single-stage centrifugal pump, pilot pump, bearing box, inlet pipe, outlet pipe, foam mixing system, and outlet main valve. Fire pump, the first wear is the gap seal and bearing components. The gap of the pump seals its gap from zero . 3mm change to 1 . 0mm , the gap increases, so that the pump's flow and efficiency drop. The common faults of the waterway system are the water pump bow l is not on the water, the outlet water pressure is not high, the pump operation is different, the jet flow is unstable and so on. The common failures and reasons of the ascending ladder ladder fire truck water system are shown in Table 2 .
Table 2 Analysis of Common Failures of the Water System of the Fire Truck
2 . 3 hydraulic system failure
The pressure adjustment of the hydraulic system of the ascending ladder ladder fire truck is mainly to set the pressure value through the setting of the pressure reducing valve, and the pressure value can also be set through the unloading of the relief valve. When the pressure value of the control valve for setting the pressure value does not meet the specified value, the hydraulic system may not work properly. The concrete manifestation is that the horizontal leg stretches slowly, does not move or even shrinks. The common faults and causes of the hydraulic system of the climbing ladder ladder fire truck are shown in Table 3 .
Table 3 Common failures of the hydraulic system of the ladder ladder fire truck
2 . 4 electrical system failure
The circuit board of the climbing ladder fire truck has a short circuit or open circuit, poor contact or leakage. If the generator is overloaded, the rectifying diode is short-circuited; the overvoltage causes the regulator's switch tube to break open and the contacts are ablated without conduction; the capacitor breaks down and cannot store the charge. The electrical components in the circuit are relied on the mechanical structure, resulting in poor circuit contact due to mechanical wear or insufficient spring force. The use of different regions, climates, and topography often leads to various failures. For example, if the viscosity of lubricants increases at low temperature and the starting resistance increases, it will cause early damage to the battery; the electrical appliances that climb the ladders and fire trucks will experience aging of plastic parts and insulating materials due to high temperatures; acid rain will cause corrosion of vehicle parts.
3 troubleshooting and maintenance measures
Correctly operating and maintaining and maintaining the climbing ladder truck is an important factor in ensuring trouble-free operation and extending its service life. For the above-mentioned common failures of climbing ladder ladder fire trucks, the following exclusion and maintenance measures are proposed.
3 . 1 mechanical structure maintenance and maintenance
The main maintenance and maintenance measures in the mechanical structure failure of the climbing ladder ladder fire truck are cleaning, tightening, adjustment and lubrication. Check and maintain the connection parts and fasteners of the chassis, turntable, boom, manned platform and fire extinguishing device of the climbing ladder truck at all times, and keep it intact, fastened and locked. Add fuel, lubricating oil, and grease at any time. Ladder fire truck chassis, turntables, jibs, manned platforms, and contact parts for the movement of fire extinguishing devices shall be lubricated and kept lubricated every month or after actual use, making them flexible and reliable. At the same time, we must also promptly supplement and purchase some fire-fighting articles and clean air, fuel, oil, and hydraulic filters.
3 . 2 Maintenance and Maintenance of Water System
The following are the main measures for the maintenance of the water ladder system for climbing ladder ladder fire trucks:
(1) The pump must not be operated in the anhydrous state. The pump must be disconnected immediately when the water is cut off.
(2) When the weather is cold, after the water pump is used, the water in the outlet and the water pump must be drained, and then purged with a purge system to prevent the water pump and the pipeline from freezing. It is necessary to start the heating system.
(3) When the boom rotates, it is not possible to shoot water at the same time. When the fire truck is climbed up, it will automatically cut off the big-arm oil circuit. It should avoid suddenly starting or suddenly stopping the water jet and pressure; the decompression should be carried out slowly to prevent water hammer phenomenon. Water truck outlet pressure should not be greater than 1 . 3MPa .
3 . 3 Hydraulic system maintenance and service
The hydraulic oil of the hydraulic system of the climb ladder ladder fire truck is the working medium that drives the movement of each mechanism, so it is necessary to keep the hydraulic oil clean. Clean and replace every three years.
During the maintenance and repair of the hydraulic system of the ascending ladder ladder fire truck, it is necessary to strictly prevent debris from entering the hydraulic system, because the sundries dissolved in the system or components will cause the hydraulic system and the actuator to be out of adjustment, run out of control, and even climb the ladder. The fire truck cannot be normal. Use, the great harm, must cause the operator to pay close attention to.
Job should always check fuel tank, fuel in the tank when the traveling state when the oil standard pitch 4/5 or less, should be added in order to ensure the normal operation of each mechanism. Added hydraulic fluid to the oil limit.
After the hydraulic system is maintained, air may enter the system. The air dissolved in the oil will cause the actuator to move and cause crawling, noise, and even vibration. At this time, all the actions of the climbing ladder ladder fire truck will start from the whole Do it several times until the movements are smooth and the air in the system will drain from the tank.
3 . 4 maintenance and repair of electrical system devices
The operator should always check whether the power supply of a battery is sufficient, whether the alarm indicator and the light are bright, whether the electronic control switch is sensitive and reliable, whether the electrical circuit has a virtual connection, a false welding, or a virtual connection. If problems are found, repair or replace the component immediately. . Do the climbing ladder ladder fire truck electrical control system's effective operation. It is necessary to check whether the brush contacts of the conductive system on the center and the off-slewing joint are firm and have good contact. If problems are found, timely adjustments and maintenance are needed to ensure smooth flow of the power supply system to and from the vehicle.
Always check whether the current controller, potentiometer, and circuit board that control the operation of the electro-hydraulic proportional valve and the connector are firm and tight and the contact is good.
In addition, the operator should also maintain a clean and dry external environment at the electrical system components, accessories, and line junctions.
The rate of failure of the climbing ladder fire truck in actual operations is small, but improper operation and insufficient maintenance can also cause various failures. Through the analysis of the mechanical failure of the climbing ladder ladder fire truck, water system failure, hydraulic failure and electrical system failure, the corresponding troubleshooting and maintenance measures are proposed to help the correct operation, maintenance and maintenance of the climbing ladder ladder fire truck, and extend the climbing ladder The service life of the fire truck.
This article from the "Western China Science and Technology" in January 2015, Volume 14, Number 01, Issue 306, re-edited by China Rescue Equipment Network.
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