Taking the rubber airbag of the air spring as the main object, the surface temperature of the air spring brake disc is used, based on the simulation test mainly based on the thermal characteristics of the continuous downhill line with the highest thermal load, and the test bench test. The results of the following studies. (1) For a wired vehicle, if the cast iron brake disc is replaced with a forged steel brake disc, the deceleration downhill speed can be increased from the current 110km/h to 160km/h. (2) When the basic brake device of the whole train adopts the forged steel brake disc, the downhill speed of 200km/h can be obtained. (3) Test bench test results performed under the same conditions as the simulation test show that the brake disc temperatures during emergency braking after deceleration downhill are approximately equal. (4) When the local temperature of the brake disc exceeds the use temperature limit, the heat energy can be dispersed evenly by improving the heat dissipation by improving the shape of the fin inside the brake disc. (5) In the future, it is necessary to further study brake discs suitable for use in higher speed vehicles. The material test piece was subjected to an artificial accelerated aging test considering the aging factor, and the actual performance of the spring and the aging degree of the physical properties of the air bag were tested for the actual use of the air spring (hereinafter referred to as the vehicle use piece), and the durability was evaluated. . The degree of aging is evaluated by taking into account the complex stress conditions of the air spring during vehicle operation, and sampling the test piece for the upper, middle, and lower positions of the airbag or the vertical and horizontal directions. The durability evaluation results of the air spring are described below.
The structure of the air spring and the sampling position of the test piece are used as the air spring airbag for aging evaluation. The JR line has an airbag having an effective diameter of 550 mm used on the bolster bogie. For the appearance of the bolster bogie. The air spring is located in the upper part of the bogie and supports the car body, which has the function of absorbing vibration. The airbag is a film sheet of an air spring. Since it is made of rubber, it is inevitably affected by aging caused by ultraviolet rays or alternating stress. The airbag is composed of three layers of inner rubber, fiber layer and outer rubber. The study is based on the outer rubber which is subjected to alternating stress (or heat) and exposed to ultraviolet light. Air springs are soft and easy to bend, and they are subject to large and complex vibrations during operation, so it can be speculated that the aging conditions vary greatly depending on the position or orientation. The position of the test piece taken by the air spring is as shown in Figs. 1 and 2 .
Air spring (with bolster bogie) Figure 2 Sampling position and direction of the test piece (1 side) It is first conceivable that one side of the air spring viewed from the side of the vehicle is affected by ultraviolet rays. On the other hand, the o-plane viewed from the running direction of the vehicle is the one that is less affected by the ultraviolet rays. Depending on the location, it can be inferred that the stress conditions are different, and it is conceivable that the vibrational conditions are different in the vertical direction and the horizontal direction in each part, and the stress conditions are also different. Therefore, in each part, in order to test the physical properties in the vertical direction and the horizontal direction, two kinds of test pieces which are directional are considered, and the air springs are taken out from the same bogie for one year.
The purpose of the test was to carry out an artificial accelerated aging test on the outer rubber of the airbag using the rubber test piece of the same material, and at the same time, the evaluation of the current air spring was carried out. The artificial accelerated aging test is based on three items of heat, ultraviolet ray and alternating tensile stress related to the main aging factors of air spring airbags. After accelerated aging, the tensile strength, dynamic viscoelasticity and NMR-induced nuclear magnetic mitigation time were measured. T2L. Also evaluated the characteristics of the current air spring, the burst pressure and the tensile strength, dynamic viscoelasticity and physical properties of the T2L.
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