The Performance Predicting And The Test Standard Discussion Of 120 Distribution Valve At Low-temperature

Along with the rapid development of the country,as the vitals the economy development,the railway transport is attented by various facet. Due to the low speed , railways transport does not suit for the rapid development of the country economy modernization construct. To solve the conflict between the lack transport ability and the increasing requirement,the Railway Ministry regarded the speed-up and the heavy-haul as the direction. From 1997,six speed-up on great area had been actualized,as the equipment of security,air brake system became the emphasis of research.There is a wide spread of area and a big different temperature between the south and north of our country, even the temperature is very low in some areas in winter. The vehicles of our country has much more problems in low-temperature during recent years,and especially braking system problems,vehicle braking systems need to have a good temperature adaptability,especially excellent low-temperature property. Existing test standard is targeted mainly at normal temperature environment test. Breakdown of braking system at low-temperature ,it can satisfy the normal temperature test standard,many braking system workers realize that it is necessary to know the low-temperature property of braking system,and realize the importance to establish the test standard at low-temperature.This paper studies it's property of low temperature with the simulation method, Using 120 distribution valve test rig simulation programme, this paper simulated the 120 distribution valve test in 705 test rig at the low-temperature. There are 16 kinds of test , include main valve test and emergency valve test. According to the nature of experiments, the tests can be divided into two types, such as filling exhaust tests and the sensitivity tests.And it came to the conclusion that the performance of 120 distribution valve has changed to some extents. Temperature has some extents influence to the result of some tests. The time of charging and exhausting has increase at low-temperature comparing the results of -50℃and 27℃, the charging time of auxiliary reservoir increases 16.9%, while the release test the exhausting time of brake cylinder increases 15.9%;The sensitivity of brake,release and emergency has increase at low-temperature, comparing the results of -50℃and 27℃, brake sensitivity increases 8.5%,release sensitivity increases 9.2%, emergency sensitivity increases 3.6%; some tests are not affected by temperature ,such as the performance test quick seveice limiting valve,accelerated release test,main valve release test and so on.According to the simulation results of low-temperature test, finding the brake system change rule at temperature, predict the performance change of 120 distribution valve, the paper determines the 120 distribution valve test standard in 705 test rig at low-temperature and provides some references to establish 120 distribution valve test rig test standard at low-temperature.