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INDEX >> NEWS >> Basic Structure of Railway Vechile - Braker

railway wagon braking is artificially stop the movement of railway wagons, including making it slow down, do not accelerate or stop running. On the railway wagon or locomotive brake has been lifted or reduced its braking effect, it is called "mitigation." Complete set of equipment for the purposes of the brake and ease while mounted on the railway wagon, the railway wagon always called "brake." "Brake" and "brake" known as the "gate." Implementation brake often referred to as "the gate" or "Lower Gate", the implementation of mitigation is referred to as "loose brake."

"railway wagon braking device" includes locomotive brakes and the vehicle brakes. The difference is that in addition to the locomotive like to make it as a vehicle braking and ease of their equipment, but also has a role to manipulate the whole railway wagon braking devices.

Before introducing braking device, to talk about the railway wagon braking mode.

railway wagon braking on the manipulation of use can be divided into "normal braking" and "emergency brake" two. Under normal circumstances to regulate or control the speed of the railway wagon, including the implementation of pit parking brake, known as the "common brake", which is characterized by a relatively mild effect and braking force can be adjusted. In case of emergency as soon as the railway wagon stopped in force in braking, known as the "emergency brake" (also called "very brake"), which is characterized by relatively rapid action and take the railway wagon braking capacity to spend all .

From the moment of starting the implementation of the brake, the moment to stop the railway wagon speed is reduced to zero, the railway wagon passing distance, called the braking distance. This is a comprehensive reflection of the railway wagon braking device performance and results of the major technical indicators. railway wagon weight, the higher the speed, the less easily in a short time, a short distance to stop. So, between the speed of the railway wagon and the braking distance relationship? If after a railway wagon run by a 15-car at 50 kilometers per hour when it implemented the brake, you can stop within 130 meters to; then when the speed increased to 70 km, it is to move forward with 250 meters to stop; When the railway wagon when the speed of 100 kilometers per hour, and its braking distance to 570 meters; and when the railway wagon speeds up to 120 kilometers, going over 800 meters braking distance. Thus, the doubling of railway wagon speed, braking distance to increase more than threefold. However, China's current "railway technology management procedures," states that "the railway wagon at the railway ramp on any emergency braking distance, defined as 800 m". That is to say, in order to improve railway wagon speed, must adopt more advanced braking device.

Currently, the brake mode used for railway vehicles is the most common shoe brake. Cast iron or tile-like brake pads made ​​of other materials, during braking hold of the wheel tread, by friction wheels stop turning. In this process, the brake device to great kinetic energy into thermal energy dissipated to the atmosphere. And this braking effect is good or bad, but it depends on the friction and heat dissipation capability. When you use this braking mode, the brake shoe friction small area, most of the heat load from the wheels to bear. The higher the speed of the railway wagon, the wheel brake thermal load is greater. Such as cast iron brake shoes, brake shoe temperatures can melt; Even with more advanced synthetic shoe, the temperature will be up to 400 ~ 450 ℃. When the wheel tread temperature increases to a certain extent, it will make the tread wear, cracks or peeling, it will affect the life also affect driving safety. Visible, the traditional tread brake shoe can not meet the needs of high-speed railway wagons. So a new type of brake - disc brake emerged.

Schematic disc brake disc brake, which is installed on the axle or brake disc in the car spoke plate side, with the two caliper brake pads made ​​of synthetic materials pressed the brake disc side, by friction braking force, the railway wagon stops. Because the force is not in the wheel tread surface, disc brake wheel tread can greatly reduce the heat load and mechanical wear. Also braking smooth, almost no noise. Disc brake friction area is large, and you can install a number of sets required, the effect was significantly higher than cast iron brake shoe, especially for the more than 120 kilometers per hour high-speed railway wagon, which is widely used in various countries of the reasons for disc brake lies. But the downside is that there is no wheel tread wear shoe scraping, will make the wheel rail adhesion deterioration; brake disc so unsprung weight and increased shock and vibration, traction power consumption operation.

Railway rolling stock brake and steering control by braking the driving force behind the different ways, can be divided into: hand brake, air brake, electro-pneumatic brake, electromagnetic brake and vacuum brake.

Fixed hand brake chain structure diagram is the human hand brake for braking the driving force to the rotation direction and the hand size of the hand wheel to manipulate the control. Simple structure, low cost, is the most ancient railroad history, its most tenacious brake. Early railway development, the only such brake locomotives, each car is equipped with a system or several car mobilization orders collaborative manipulation by the driver flute, due to brake weak, slow, direct manipulation of the driver is not easy, so soon to be replaced by a non-human brake, hand brake to become an alternate auxiliary brake.

Air Brake is a brake pressure air as the driving force to change the pressure of air pressure to manipulate the control. Braking force is large, sensitive steering control is convenient. China's railway used to the pressure of the air referred to as "wind", the air brake referred to as "air gates." Air Brake is divided into straight-through and automatic two categories, straight-air brake no longer be used. Automatic air brake schematic

Features automatic air brake is a brake cylinder pneumatic (pressurized), the occurrence of remission railway wagon pipe exhaust (pressure) when. The advantage is that separation occurs when the railway wagon accident, when the brake hose pulled off the railway wagon pipe pressure falling sharply, three-way valve piston automatically and quickly move to the brake position, so the railway wagon can automatically until the parking brake quickly. This not only improves the safety of the railway wagon, but the railway wagon started braking effect of the front and rear of the time difference is small, that is, the brake and mitigation - consistency is better for marshalling longer railway wagons; so get in on the world's most extensive railway applications.

Electro-pneumatic brake electrical schematic is electronically controlled pneumatic brake air brake for short, is the installation of a solenoid valve in the air brake on the basis of other electrical control components formed. It is characterized by the braking action of the steering control "electrical control", but the driving force or the braking action of the air pressure. Moreover, in the electronically controlled brake failure for any reason, it can still implement the "air control" (air pressure control), temporarily turned into air brake. In the high speed railway wagon or marshalling very long, air brake hard to meet the requirements, the use of electro-pneumatic brake can greatly improve the front and rear of the railway wagon braking and mitigation consistency significantly reduce railway wagon longitudinal impact and shorten the braking distance, high-speed railway wagon many of the world have adopted the electro-pneumatic brake, China's Guangzhou-Shenzhen line quasi-high-speed passenger railway wagons and some trunk speed passenger also used electro-pneumatic brake.
   
There is a schematic diagram of a vacuum brake vacuum brake, which is characterized as the driving force is the atmosphere in order to change the "vacuum level" to manipulate the control. When the brake handle into remission bit, vacuum tube communicating with the railway wagon, the railway wagon pipe and brake cylinder air is pulled out, the railway wagon pipe and brake cylinder up and down both sides have maintained a high vacuum, piston fall due to weight piston rod extending outward. When the brake lever to the brake position, railway wagon pipe to atmosphere, the atmosphere into the railway wagon pipe and brake cylinder piston below. Due to be completed when the exhaust valve has been falling ball is turned off, the atmospheric pressure can not make it to suppress the valve port open, so air can not enter the top of the piston. Push down the pressure on the piston moves the piston rod to the cylinder condensation occurs braking effect. Vacuum brake system in a non-human motives structure is relatively simple, the price is cheaper, maintenance is also more convenient. However, due to limited atmospheric pressure itself, "absolute vacuum" and difficult to achieve, and that requires a larger and thicker brake cylinder tube railway wagons, so some preclude the use of a vacuum brake railway, with the traction weight and run improve the speed, have been or are the transition to air brake.

 


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