Railway rail fasteners are parts on the track used to connect rails and sleepers (or other types of under-rail foundations), also known as intermediate connecting parts. Its function is to fix the rail on the sleeper, maintain the gauge and prevent the longitudinal and lateral movement of the rail relative to the sleeper. The railway rail fastener system is divided into: shrapnel fastener system, gusset fastener system, and elastic strip fastener system. The gusset type fastener is composed of a gusset plate, a threaded spike, a spring washer, an iron seat and a buffer pad. The threaded spike is anchored in the reserved hole of the concrete sleeper bearing platform with sulfur cement mortar, and then the gusset plate is fixed by bolts. fasten.
There are elastic strips I, II and III types of clip fasteners. Type I elastic strip is composed of ω elastic strip, screw spike, gauge baffle and rubber pad. Its buckle pressure is insufficient and the elastic range is too small.
The shape of the elastic strip type II is the same as that of the elastic strip type I, and the elastic range is not less than 10mm. The buckle pressure is higher than that of the elastic strip I type.
Type III spring clip is a shoulderless fastener, which is suitable for heavy transportation and high-density transportation conditions. It has the advantages of high buckle pressure and good elasticity. In particular, the concrete shoulder is eliminated, and the lateral force of the rail bottom is eliminated. possibility of lateral displacement.
Features of rail fasteners:
1) Have enough strength and durability
Rail transit has a long operation time, high traffic density and poor maintenance conditions, requiring rail fasteners to have sufficient strength and durability to ensure driving safety.
2) Have a certain gauge and level adjustment performance
Rail transit mostly adopts the overall track bed structure, the line curve radius is small, and the rails are worn. This requires that the fasteners should have a certain gauge and level adjustment performance to solve the gauge and rail level excess caused by the wear of the curved rail and the uneven settlement of the structure and construction errors.
3) have good insulation properties
Rail transit generally uses the running rail as the return rail, which requires the fasteners to have good insulation properties to prevent the leakage of current through the fasteners, resulting in electrical corrosion of structural steel bars and municipal pipelines.
4) Good vibration damping elasticity
Urban rail transits such as subways pass through residential areas, and have high environmental protection requirements for vibration reduction and noise reduction. The rail fasteners must have good vibration reduction performance to attenuate rail vibration and reduce noise transmission.
5) There is a certain general interchangeability
The fastener structure should be simple, with few parts and components, with certain general interchangeability, low cost, and convenient construction and maintenance.