Fasteners are divided into two types according to the sleepers laid: wooden sleepers and concrete sleepers. According to its structure, fasteners can be divided into: according to fasteners, they are rigid and elastic; According to the sleeper structure: with and without shoulders;
According to the connection mode of sleeper, pad and buckle, it can be divided into two types: non-split and split; According to sleeper, there are wooden sleeper fasteners and concrete sleeper fasteners. All the above types of fasteners are laid on the railways in China.
fastener
I. Functions and classification methods of rail fasteners
Fasteners are an important part of the track, and the rail and sleeper are connected together through fasteners. Fasteners are used to fix the correct position of the rail, prevent the longitudinal and lateral displacement of the rail and prevent the rail from overturning. At the same time, they can also provide necessary elasticity and insulation performance, have certain adjustment ability to track gauge and level, have as simple structure as possible, and are convenient for manufacture, construction and maintenance. Fastener consists of two parts: rail fastener and under-rail pad.
Design principles of fasteners
Fasteners should have sufficient strength, fastening force and durability. On the ballastless and pillowless track of viaduct, the fasteners must also have good elasticity, and the gauge and gauge should be adjusted horizontally to adapt to the creep of prestressed beam and uneven settlement of pier, and meet the requirements of vibration reduction, noise reduction and insulation. The fastener is simple in structure, standardized, universal and low in cost. The iron parts of fasteners should be treated with anti-corrosion.
Second, wooden pillow fasteners There are two main types of wooden pillow fasteners: separated and mixed.
Third, the concrete pillow fastener
The research and development of fastener system in China has a history of more than 50 years, and many fastener types have been developed. Now the main types of fasteners are summarized and explained.
1. Fastener system for ballasted track
With the development and application of concrete sleepers, China began to study fasteners for concrete sleepers from 1957, and developed various fastener types, such as bolt buckle plate fastener, 63 buckle plate fastener, 67 arch spring plate fastener, 70 buckle plate fastener, spring plate Ⅰ fastener, spring plate Ⅰ adjustable fastener, spring plate Ⅱ fastener and spring plate Ⅲ fastener. With the development of passenger dedicated line construction, elastic IV fasteners and elastic V fasteners have been newly developed. The following mainly introduces several commonly used fastener types.
1. 1 gusset fasteners
Bolt gusset plate fasteners, 63 gusset plate fasteners and 70 gusset plate fasteners all adopt rigid gusset plates, and concrete sleepers are equipped with shoulder pads. The bolt for fastening the gusset plate is either fixed in the splint in the reserved hole of the concrete sleeper, or screwed into the wooden sleeve embedded in the sleeper from the lower part, or anchored in the reserved hole of the concrete sleeper with a sulfur anchor. This kind of fastener has poor elasticity and large buckle pressure attenuation, which has been completely eliminated in the main line.