Turnout Construction and Maintenance
- What are the differences in structure and application scenarios among single - switch turnouts, symmetric turnouts, and three - way turnouts?
Single - switch turnouts have a relatively simple structure, consisting of a switch mechanism, a frog and guard rail, and a connecting part. The main line is straight, and the side line branches from the main line to one side. It is suitable for the line connection in general stations, can realize the lateral passage of trains, and meets the basic turning needs of most railway lines. The bisector of the frog angle of the symmetric turnout is perpendicular to the center line of the main line, and the two - side lines are symmetric. It can shorten the length of the turnout and increase the lateral passing speed of the train. It is often used in marshalling yards, freight yards and other places where the compactness of line layout and the passing speed of trains are required, which can improve the efficiency of shunting operations. The three - way turnout is equivalent to two single - switch turnouts combined back - to - back, which can make the train turn to two different directions at the same time. It is suitable for areas such as the throat area of the station where the space is limited but more line - connection directions are needed. It can reduce the number of turnouts and save floor space, but the structure is complex and the maintenance is more difficult.
- What are the common faults in the switch mechanism part of the turnout, and how to carry out daily inspection and maintenance?
Common faults include non - close contact of the switch rail. It may be caused by sundries between the switch rail and the stock rail, loosening of connecting rods or faults of the switch machine; switch - machine faults, such as motor damage, gear wear, oil - way blockage (for hydraulic switch machines), etc., which affect the switching action. Daily inspection includes checking whether there are sundries between the switch rail and the stock rail and cleaning them regularly; checking whether the bolts of the connecting rods are loose and tightening them in time; checking whether the appearance of the switch machine is damaged, whether the running sound of the motor is normal, and whether the oil level and oil pressure of the hydraulic switch machine are within the normal range. Maintenance measures include regularly maintaining the switch machine, such as adding lubricating oil to the motor, replacing worn gears, cleaning the oil - way and replacing the oil for the hydraulic switch machine; adjusting the close - contact state of the switch rail and the stock rail to ensure the flexible and reliable action of the switch mechanism.
- What is the role of the frog and guard rail in the turnout, how to detect its wear degree, and how to deal with it when the wear exceeds the limit?
The frog is a device that enables the wheels to pass smoothly through the intersection of two rails, and the guard rail is used to guide the wheel flange to prevent the wheels from derailing. The two work together to ensure the safe passage of trains through the turnout. The wear degree of the frog and guard rail can be detected by using measuring tools, such as using a caliper to measure the thickness of the frog point rail, wing rail, and the wear amount of the guard rail. When the wear of the frog point rail and wing rail exceeds the specified limit (for example, at the position where the top width of the point rail is 20mm, the vertical wear exceeds 6mm on the main line, 8mm on the arrival and departure lines, and 10mm on other station lines), or the wear of the guard rail affects its guiding function, it needs to be replaced in time. For slightly worn frogs and guard rails, methods such as surfacing welding repair can be used to extend the service life, but strict inspection is required after repair to ensure compliance with technical standards.
- What problems may occur in the connecting part of the turnout during long - term use, and how to prevent and solve them?
The rails in the connecting part may have problems such as wear and cracks, which are caused by the impact force of the train passing and the frequent bending action; the fasteners may loosen or fail, affecting the stability of the track. Preventive measures include regularly performing flaw detection on the rails in the connecting part to detect crack hazards in time; strengthening the inspection and tightening of fasteners and regularly replacing worn fasteners. Solutions: for rail wear, grinding and repair can be carried out, and when the wear is serious or cracks appear, the rail is replaced; for loose fasteners, they are tightened in time, and failed fasteners are replaced to ensure the stability of the rails in the connecting part and the smooth and safe.
- What are the special technical performance requirements for turnouts on high-speed railways? How do they differ from conventional railway turnouts?
High-speed railway turnouts require higher smoothness to ensure smooth and comfortable train travel at high speeds. For example, these components require higher geometric precision and tighter control of track height differences. They also require greater stability to withstand the immense dynamic forces of high-speed trains, resulting in higher structural strength and rigidity. Switches also require faster actuation to accommodate the rapid transit of high-speed trains between different tracks. Compared to conventional railway turnouts, high-speed railway turnouts require more sophisticated manufacturing processes, stricter installation and commissioning requirements, and more advanced maintenance and inspection technologies. These include the use of high-precision measuring instruments for routine inspections and intelligent monitoring systems for real-time monitoring of turnout operating conditions.