At school, when we see knowledge points, we collect them first. Knowledge point refers to the focus, core content and key part of a module knowledge. What knowledge points do we really need? The following are the reasons for the separation of railway freight car couplers and the preventive knowledge points I collected for you. Welcome to share.
Under the situation of speeding up and overloading of trains in China, there is an automatic separation fault of freight car couplers in railway freight car transportation. What is even more worrying is that the separation of railway freight car couplers is harmful and has certain suddenness. When the freight car runs to a certain undulating slope section, especially in the ultra-long downhill section, bridge, tunnel and other sections above 20‰, it is easy to separate the coupler, which not only interferes with the normal operation order of the train, but also seriously affects the driving safety.
Abstract: The development trend of railway freight transportation in China is showing the characteristics of high speed, long distance, heavy load and large grouping. Under the condition of heavy freight car transport task, high speed and heavy load, the separation of freight car couplers restricts freight car transport, so it is necessary to analyze the reasons for the separation of railway freight car couplers and put forward corresponding preventive measures.
Keywords: railway; Trucks; Coupler separation; Reason; prevent
introduce
Under the situation of speeding up and overloading of trains in China, the automatic separation of freight car couplers in railway freight transportation is caused by the intensification of longitudinal impact and vertical force during the operation of freight cars, which greatly affects the safety and smoothness of railways and interferes with the order of freight transportation. This paper focuses on the analysis of the reasons for the failure of freight car couplers, and puts forward corresponding preventive measures to improve the quality of railway trains.
1 hazard analysis of coupler separation of railway freight cars
The coupler separation of railway freight cars is harmful and has certain suddenness. When the freight car runs to a certain undulating slope section, especially in the ultra-long downhill section, bridge, tunnel and other sections above 20‰, it is easy to separate the coupler, which not only interferes with the normal operation order of the train, but also seriously affects the driving safety. The 13, 16 and 17 series couplers commonly used in freight cars still have the problems of long time and serious wear, which leads to multiple failures in the separation of freight car couplers. Therefore, it is necessary to analyze the causes of the coupler separation failure of railway freight cars, strengthen the maintenance of freight cars from the source, and ensure the safety of train operation.
2 Analysis of the reasons for the separation of railway freight car couplers
2. 1 Reasons for automatic separation of railway freight car couplers
2. 1. 1 Bad locking leads to automatic separation.
This is mainly caused by too many locking positions of freight car couplers and too large differences between couplers, among which: ① The locking positions of couplers are too large. This is caused by the loss of the locking surface at the tail of the hook tongue. Under the action of friction, the coupler lock iron and coupler tongue rub against the inner wall of the coupler cavity, and the gap of the coupler tongue pin hole is too large because of the loss of the hole sleeve. When the truck runs to the curve section, it will automatically unhook. ② The difference between couplers is too great. The coupler of the freight car should have a certain height from the rail surface, which is set for safety. If the gap between two connected couplers is large, or the hook joist falls off, bends or sags, it is easy to automatically unhook, which will aggravate unhooking in soft subgrade or high slope.
2. 1.2 Causes of coupler separation due to poor unlocking status.
① The anti-jump clearance is too large. The wear state of the top of the hook shaft, the upper locking pin lever and the lower locking pin of the hook lock iron will lead to excessive anti-jump clearance. In this state, the upward movement of the hook lock iron can not resist the tail of the hook tongue, which is easy to cause unlocking separation.
(2) Anti-jump parts are worn and fail due to geometric changes. The anti-jump loss of the upper coupler and the top loss of the upper locking pin rod will affect the position and angle of the upper locking pin to a certain extent, so that the anti-jump protrusion of the upper locking pin cannot be locked with the anti-jump platform of the hook cavity, resulting in the failure of the anti-jump platform.
(3) The plane welding of the shackle lock platform is poor. When the coupler lock platform is poorly welded, the surfacing area will be reduced, uneven or uneven, resulting in the coupler lock iron jumping, unable to resist the coupler lock tail, resulting in unlocking separation.
④ The slack margin of the upper coupling chain is insufficient. The length of the coupling chain acting on the freight car has its limit. Once the loose edge is too small, the coupler will be lifted off because the coupler chain is too tight when the truck is running. The main reasons that lead to too small slack allowance of hook chain are: the lateral value between hook head and center line of freight car is too large; The reasons such as over-limit buffer freedom will cause the lock pin to leave the anti-jump position and cause the coupler to unlock and separate.
⑤ The hook rod is not good. When the lifting lever of down-moving coupler bends and falls into the seat groove, it is easy to cause the unlocking problem caused by inaccurate landing angle.
2.2 Separation caused by the fracture of railway freight car couplers
During the operation of railway freight cars, the coupler head and coupler body will crack or break, which is mainly caused by the coupler structure itself and improper maintenance. When the upper and lower hooks bear too much load and their own strength is insufficient, cracks will occur due to too concentrated stress. At the same time, due to improper maintenance, there is an excessive gap between the coupler tongue and the traction force in the coupler cavity during the coupler assembly process, which leads to cracks when bearing a large impact force.
In the running process of freight cars, coupler tongue cracks will occur due to emergency braking or excessive traction. Because the corner of the hook tongue side is the stress concentration point, fatigue cracks are easy to occur.
2.3 Separation caused by the fracture of the coupler tail frame of railway freight cars
In the state of concentrated stress, the coupler tail frame of freight cars is prone to crack at the corners and around, especially when there are defects such as sand holes and slag inclusion in the coupler tail frame, which is more likely to cause fracture and lead to train separation.
2.4 Separation caused by subjective operation of locomotive crew members
When the freight car is running and stopping, if the locomotive crew only adopts resistance braking measures instead of air braking measures, the train coupler will be decoupled. Especially, in order to prevent the train from sending out signals, freight cars have to go through the process of high-speed operation-braking and deceleration-starting the train again. In this process, the train can't bear the rapid compression and tension pressure without stopping completely, so that the lock iron moves up and separates.
2.5 the influence of complex environmental factors
During the operation of freight cars, they have to go through different complex line environments. When the ramp fluctuates greatly or the track is irregular, the empty car will have impact and vibration under the action of inertia, which will lead to the separation of couplers.
3 Railway freight car coupler separation preventive measures
3. 1 Strictly master the process standard of coupler assembly.
In the process of assembling coupler parts, the coupler body, coupler tongue, locking pin and locking pin rod should be carefully and comprehensively measured to make the coupler meet the assembly requirements. The production of freight car coupler chains should also be carried out according to the drawings, and the slack of coupler chains and the lateral momentum of freight car coupler bars should meet the technical specifications and standards. The outer seat groove of the upper moving hook rod of freight car can be transformed into the lower moving type to ensure the accurate position of the hook rod.
3.2 From the coupler maintenance content to prevent the coupler from separating.
3.2. 1 Check the reset of the locking pin on the coupler.
Three-state test must be carried out for the inspection of coupler composition, and the inspection of coupler lock pin reset test should be added at the same time. The specific measures are as follows: observe the lifting height of the lifting rod of the hook, and check whether the stop of the locking pin matches the locking pin hole after descending. In order to prevent false locking, this inspection process must be checked three times. The inspection focuses on the wear and repair of the front part of the lock pin and the wear of the hook lock shaft.
3.2.2 Check the composition of the three-link locking pin.
During the second world war. 13 top-moving coupler has excessive wear, such as inflexible rotation of locking pin; The rivet shaft is loose; Excessive wear of the anti-jump platform and the shaft opening of the upper locking pin rod. Therefore, it is necessary to replace the excessive wear of the suspension shaft opening of the upper locking pin. For the problem of inflexible rotation of the locking pin, it can be adjusted and coated with molybdenum disulfide dry lubricant to ensure its flexible operation. 3.2.3 Check the key parts of the hook cavity.
After long-term operation, there will be great wear inside the hook cavity. Because of its narrow working space, it is necessary to develop maintenance equipment in the hook cavity to improve the recovery of the shape and size of the hook cavity.
3.2.4 Check the longitudinal and transverse clearances of the coupling.
In the process of coupler assembly inspection, it is necessary to check the technical standards and limits of coupler transverse clearance. If the transverse clearance is too large, it is necessary to re-match the coupler tongue and lock iron. At the same time, the longitudinal clearance of the coupler should be checked, especially when the coupler tongue is pulled outward, to determine the degree of fit of the coupler tongue under impact conditions. You can also rotate the hook tongue manually and observe whether the hook tongue pin rotates with the stress state to prevent the problem that the upper and lower hook ears are not concentric.
3.3 From the application point of view, measures to prevent coupler separation
3.3. 1 The application workshop should focus on checking the coupling state.
For the 16 and 17 couplers of the train, it is necessary to determine the insertion position of the anti-jump pin, find and deal with the accidental loss and fracture of the anti-jump pin in time, and ensure its safe and stable connection state. When the coupler difference exceeds the limit or the height is out of compliance, it should be adjusted appropriately. When the train is compiled at the station, it should be confirmed that all couplers are in good working condition.
3.3.2 Preventive inspection on appearance of coupler parts in workshop.
During operation, the appearance of coupler should be checked preventively, and the following faults should be dealt with in time: ① The coupler tail flat pin, coupler tail frame support plate and coupler joist bolt are loose, which should be tightened and repaired in time, and the cotter pin should be installed. (2) The coupler and coupler tail frame are broken, and the impact seat is damaged, which shall be repaired according to regulations. (3) For the collision between the coupler and the impact seat, check the appearance of the vehicle coupler after the dumper is unloaded. If the coupler is twisted off, replace the accessories in time. (4) Attention should be paid to the use of vehicles equipped with anti-jumping wood and coupler buffer blocks.
3.3.3 The application workshop shall strictly implement the measures of binding couplers to prevent couplers from falling off.
In the process of use, we should pay attention to the measures to bind the coupler under the following circumstances: ① When the slack of the upper coupler lever chain is less than the specified value; (2) When the coupler lifting lever is bent and deformed; (3) When the hook lifting lever of the lower coupler is bent and deformed or the gap between the hook lifting lever and the seat groove is inconsistent; (4) When the hook seat is loose or damaged; ⑤ There is no downward-moving coupler with anti-jump bolt. ⑥ After the reconnection of the separation accident, the locking iron of the separation coupler should be fastened to prevent the secondary separation. In addition, for military, special and special trains and passenger trains, the "three-in-one" system of hook lifting rod, hook locking pin and angle stopper should be strictly implemented.
3.3.4 Inspection work
During the operation, the vehicle inspector shall dynamically check the train coupler, retarder and their connection status, and notify the operation site for confirmation in time, and notify the bureau to arrange parking for proper disposal to ensure safe and stable operation.
4 conclusion
To sum up, the reasons for the coupler separation failure of railway freight cars are complicated and need to be analyzed objectively and comprehensively. Coupler is the key component of freight car connection, and its performance is directly related to the running stability of freight car. Under the condition of large-scale railway speed-up reconstruction, we should pay attention to the common coupler separation faults of 13, 16 and 17. Aim at that failure of coupler anti-jump device,
Take the exam and contribute.
[1] Pang Yanfeng, Chen Kai. Application of coupler buffer device for domestic urban rail vehicles and the idea of unified type [J]. Railway vehicles, 20 1 1(0 1).
[2] Wang, Wu Jinguo. Suggestions on improving the inspection quality of railway freight cars [J]. Science and Technology Wind, 20 15( 12).
[3] Wang Fujiang Failure analysis and suggestions on coupler tongue of railway freight cars [J]. Scientific and technological innovation and application, 20 16( 10).
develop
classify
Railway passenger cars and railway vehicles are divided into two categories according to their uses: railway passenger cars and railway freight cars. Railway passenger cars include: ① vehicles for transporting passengers, such as hard-seat cars (YZ), soft-seat cars (RZ), hard-berth cars (YW) and soft-berth cars (RW); ② Vehicles serving passengers, such as dining car (CA) and luggage cart (XL); ③ Special vehicles, such as postal vehicles (UZ), official vehicles (GW), sanitary vehicles (WS), medical vehicles (YI), experimental vehicles (SY), maintenance vehicles (EX), cultural and educational vehicles (WJ), etc. There are many kinds of railway freight cars, and different kinds of goods have different bodies, which are divided into ordinary freight cars and special freight cars. Such as gondola cars (C), boxcars (P) and flatbed cars (N) are called general-purpose trucks; It is only suitable for loading one or more goods with similar properties, such as tanker (G), refrigerated truck (B), ore truck (K), cement truck (U), live fish truck (H), special truck (TZ) and long-term goods (D). General-purpose trucks have high efficiency, but the load utilization rate varies with goods and the adaptability to different loading and unloading equipment is also different. The empty driving rate of special trucks is high, but it can meet the needs of loading and unloading of specific goods, so the empty driving rate of load capacity is high, but it can meet the needs of loading and unloading of specific goods, so the utilization rate of load capacity and volume is high, and it can match the selected loading and unloading equipment in structure, thus shortening the loading and unloading time of goods and speeding up vehicle turnover.
Railway vehicles can also be divided into quasi-gauge vehicles, wide gauge vehicles and narrow gauge vehicles according to different gauge; According to the ownership relationship, vehicles are divided into four-axle vehicles, six-axle vehicles and multi-axle vehicles according to the number of axles; According to the production materials, it can be divided into steel cars and all-steel cars.
Vehicle structure
Railway passenger cars and railway vehicles are vehicles for transporting passengers and goods. Over the years, due to the different purposes, uses and operating conditions, many types of vehicles have been formed, but their structures are basically the same, generally consisting of six parts:
(1) Car body: it is the place where the transported objects are accommodated, and it is also the basis for installing and connecting other parts.
② Body frame: it is a rectangular frame that supports the body and is the foundation of the body.
③ Running gear: it is the part that bears the weight and load of the vehicle and guides the vehicle to run along the track. Bogie structure is mostly used in running gear to ensure the running quality of vehicles.
(4) Coupler buffer device: composed of coupler and buffer, installed at both ends of the underframe. Its function is to connect locomotive and vehicle together, transmit longitudinal traction and impact force, and reduce the dynamic effect between locomotive and vehicle.
⑤ Braking device: it is the most important component to ensure the safe operation of the train, which makes the high-speed vehicles stop or slow down within a specified distance. Braking devices generally include air braking, hand braking (foot braking) and foundation braking devices.
⑥ Vehicle internal equipment: mainly refers to the equipment provided for passengers to travel by bus. Such as: seats, sleepers, luggage racks, water supply, heating, air conditioning, ventilation, car electricity and other equipment on the bus. Due to the different types of trucks, the internal equipment varies widely, but it is generally relatively simple.
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