Brake Control Laboratory
Brake Control Laboratory
Nakazawa S.-I.,Brake Control Laboratory |
Hijikata D.,Brake Control Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2017
Almost all railway vehicles have brake systems which use the tangential force between rails and wheels. It is difficult to stabilize braking performance and to prevent wheel damage because the tangential force is influenced by various conditions, such as weather, the contact surfaces of the rails and the wheels, etc. Wheel slide protection systems (WSP) are one solution adopted on many vehicles. However, in existing WSP systems, braking force is controlled using limited information from the rotational speed of the wheel. Therefore, they do not always offer optimal control when the tangential force varies frequently. This study proposes a new WSP system which can determine the quality of the tangential force from the brake cylinder pressure when wheel slips occur. The performance of the new WSP was verified through bench tests. As a result, application of the new WSP method reduced braking performance loss.
Sakamoto Y.,Electromagnetic Applications Laboratory |
Kashiwagi T.,Electromagnetic Applications Laboratory |
Hasegawa H.,Electromagnetic Applications Laboratory |
Sasakawa T.,Administration Division |
Karino Y.,Brake Control Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) (Japan) | Year: 2012
Studies have been carried out on a rail brake applying linear induction motor technology, called LIM-type rail brake. This brake is capable of generating braking forces without contact. In addition, this method decreases the rise in rail temperature, and no onboard supply is required by using dynamic braking. It is necessary however to install this brake between front and rear wheels of the bogie. A prototype rail brake system was designed and built and its electromagnetic characteristics were examined on a test bench with a roller rig. These investigations revealed that the LIM-type rail brake could be applicable for practical use.
Saga S.-I.,Brake Control Laboratory |
Karino Y.,Brake Control Laboratory |
Haga A.,Vehicle Dynamics Laboratory |
Nakahashi J.-I.,Vehicle Dynamics Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2014
In rail vehicles using composition brake shoes, the friction coefficient between the wheel and the brake shoe tends to decrease under wet conditions. In order to maintain the braking force, it is common practice to insert a metallic block to remove the water. However, the metallic block causes a localized temperature rise on the wheel tread surface under dry conditions, which is one of the factors in wheel tread damage and concave wheel tread wear. A composition brake shoe was developed to suppress the temperature rise of the wheel tread and, at the same time, maintain the brake force under wet conditions. This paper summarizes the evaluation of the composition brake shoe performance in dynamo tests, running tests and long-term durability running tests, including verification that the developed brake shoe has controlled concave wear.
Nakazawa S.-I.,Brake Control Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) (Japan) | Year: 2011
Reducing the braking distance is very important to improve the safety of a railway system. However, increasing braking force to achieve this often causes wheel slide under wet conditions because the adhesion force between the wheel tread and rail governs braking performance. This has led to the development of a number of methods including "Antiskid (Anti-lock) Brake System (ABS)," "Wheel Slide Protection system (WSP)," etc,. This paper proposes an advanced WSP using a new algorithm to detect wheel slip to achieve a higher level of performance than current systems. We also show the effectiveness of the proposed method by means of line tests.
Karino Y.,Brake Control Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2012
A caliper is a device that pinches brake discs with any given force to create braking force. RTRI has developed a pneumatic floating caliper that is endowed with simplicity and outstanding maintainability without requiring the use of a pneumatic-hydraulic conversion device (i.e. a booster cylinder) and is interchangeable with existing lightweight and compact hydraulic calipers used on Shinkansen vehicles. It is further possible to configure it to the same size as a hydraulic caliper. Testing on a braking test bench has verified that the pneumatic floating caliper offers a level of brake performance equivalent to that of the hydraulic caliper, and that the increase in temperature of the diaphragm has been suppressed to a level that does not adversely affect its lifespan thanks to the adiabatic piston arranged between the diaphragm and the brake lining.
Saga S.-I.,Brake Control Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) (Japan) | Year: 2010
On Shinkansen trains, single-step braking is applied for deceleration from high-speed running to stop without releasing the brake. As a result, marked scoring is often observed on the surface of abrasive blocks installed in wheel tread cleaner and on tread brake shoes found on conventional trains. The development of this phenomenon causes wheels to wear in a concave shape, and wear fragments may also fall onto rails. Eventually, it causes unusual vibration and extraordinary noise. In this study, attempts were made to reproduce wear fragment using a dynamo brake test stand with a view to resolving these problems. A control technique to restrain wear fragments was consequently identified, and its effectiveness was confirmed in a running test. This paper introduces the results of the dynamo test and the running test.
Hijikata D.,Brake Control Laboratory |
Nishimura T.,Brake Control Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2016
Generally braking performance of train sets is evaluated by stopping distance or deceleration. However, stopping distance and deceleration are performance indices established for a whole train set, and do not represent performance of each car individually. For more detailed analysis of detail braking performance, it is useful to have the braking force in each car. This paper describes a method, designed to estimate the braking force in each car based on the acceleration and coupler force, by using coupling devices as force sensors. Running tests results on an 18-car freight train using the devised method showed that it was possible to estimate the braking force of each car and that the estimated value was close to the theoretical value. © 2016, Ken-yusha Inc. All rights reserved.