EP2226232B1

EP2226232B1 - Controlled pneumatic tilting system in railway vehicles

Info

Publication number: EP2226232B1
Application number: EP09154500A
Authority: EP
Inventors: Ibon Eciolaza Echeverria; Gorka Aguirre Castellanos; José Germán Giménez Ortiz
Original assignee: Construcciones y Auxiliar de Ferrocarriles SA CAF
Current assignee: Construcciones y Auxiliar de Ferrocarriles SA CAF
Priority date: 2009-03-06
Filing date: 2009-03-06
Publication date: 2012-05-02
Anticipated expiration: 2029-03-06
Also published as: PL2226232T3; ATE555963T1; EP2226232A1; PT2226232E; ES2387262T3

Abstract

The invention relates to a controlled pneumatic tilting system in railway vehicles, with pneumatic springs (1.1, 1.2) for controlling the height of the body (4) with respect to the bogie (2), having opening and shut-off valves (7.1, 7.2) for said pneumatic springs, which incorporate a mechanical device formed by a rotating part (8.1, 8.2) and a seismic mass (9.1, 9.2), such that when the vehicle enters a curve said mechanical devices act on the valves which, due to the action of the pneumatic springs, makes the body (4) tilt in the direction opposite to the lateral acceleration.

Description

Field of the Art

The present invention is related to controlling the tilting of passenger railway vehicles by pneumatic means, proposing a controlled pneumatic tilting system which is simple, robust and reliable.

State of the Art

Systems are known which attempt to solve the problems existing with respect to the speed limitation of passenger railway vehicles which is conditioned by the lateral acceleration that the passenger feels when the vehicle enters a curve, this acceleration being caused by the centripetal acceleration not compensated by the superelevation of the track.
In some of the solutions for passenger vehicles the suspensions are formed by two pneumatic springs per bogie, connected by means of a pipe to two auxiliary tanks, such that said pneumatic springs give rise to vertical rigidity of the suspension aimed at improving passenger comfort.
Conventional trains having this type of suspension perform the height control by means of three or four leveling valves per car, depending on the type of train.
The operation of the leveling valves consists of introducing or extracting air from the pneumatic springs to keep the height of the body constant with respect to the bogie.
Until now, to control height, each leveling valve incorporates a lever at the free end of which there is joined a rod of adjustable length, being able to be assembled in two different ways depending on the type of vehicle in question.
In the first case, the valve is joined to the bogie whereas the rod is joined to the body at one end and to the swinging lever at the other end.
The other assembly consists of arranging the valve in the body and the rod joined at one end to the swinging lever and at the other end to the bogie.
Two types of conventional pneumatic suspensions are known, characterized by the type of leveling valves they have.
Low-flow leveling valves are generally used which, when implemented in trains, fill and empty out the pneumatic springs slowly, not leaving time to compensate the height between the body and the bogie during the curved route where inclination occurs.
Assuming the case that high-flow leveling valves are used, when the train enters a curve the valves are activated by filling more quickly the pneumatic spring of the outer part and emptying out that of the inner part, with an effect that is opposite to the natural rolling of the vehicle. However, given that all the leveling valves have a small margin of error or offset in which they are not activated, when the train is traveling in a curve there is a certain inclination in the body with respect to the bogie.
Tilting trains attempt to solve this problem by means of generating an additional superelevation of the track which inclines the vehicle towards the inside of the curve such that the generated inclination is compensated, and two methods are essentially used to do this.
The simplest method is the so-called passive tilting or natural pendulation, which consists of arranging the center of gravity of the suspension above the center of gravity of the body of the vehicle, arranging the pneumatic springs at the level of the top of the body.
This solution has the drawback that when the center of rotation is located high up, a body with smaller dimensions in the lower part must be designed to prevent having gauge problems, which compels designing a much more complex body and bogie, making the product more expensive.
The other method used is active tilting, see for example EP-A1-1190925 , which involves arranging actuators between the body and the bogie which perform the inclination of the body, in addition to adding additional mechanisms which allow laying out the desired route for the movement of the body with respect to the bogie, up to 8° of tilting being achieved.
There are two types of controls for active tilting; the first one uses acceleration signals measured in the vehicle, which generally results in delaying the tilting due to the necessary filtering and to the response time of the actual vehicle and of the actuation system.
The second control is based on using the information corresponding to the layout of the route and to the position of the train therein, such that if the train knows at all times the characteristics of the track, it tilts beforehand to describe optimal tilting for the passenger.
However, the main problem of active tilting, independently of the control method implemented, is the enormous complexity of the system, which makes the design, construction, development and maintenance of the railway more expensive.

Object of the Invention

According to the present invention a pneumatic tilting system is proposed which, as a result of its constructive and/or functional features, is truly advantageous for its application compared to conventional solutions.
The proposed system can be applied in conventional bogies without needing to add complex elements as occurred in the previously indicated active tilting solutions and without complicating the features of the bogie or of the body.
This solution is based on filling and emptying out the pneumatic springs as in a conventional train, such that when the height and tilting are controlled from the lower part, the gauge problems which occurred in passive tilting or in trains with natural pendulation are prevented.
To that end a mechanical device is implemented which incorporates a rotating part, making the system robust and reliable, and the flow of the leveling valve is increased to obtain greater response speed.
This increase of the flow can be controlled by means of three different methods, the first one depending on the lateral acceleration at the level of the bogie, the second one depending on the lateral acceleration at the level of the body and the third one depending on the movement between the body and the bogie.
For control by means of the lateral acceleration at the level of the bogie, the device incorporates in addition to the rotating part a seismic mass arranged in each bogie of the train set and joined to the rotating part by means of a rod, the rotating part being fixed at one of its sides to the bogie. Furthermore, the seismic mass is joined to the bogie by means of a spring and a shock absorber. In one variant the mass-spring assembly is replaced with an equivalent pendulum.
Therefore, when there is lateral acceleration the seismic mass moves, making the anchoring point of the leveling rod of one of the sides move up and that of the other side move down, operating the valves on both sides in opposite directions, whereby the body tilts such that said lateral acceleration is compensated.
For the control by means of the lateral acceleration at the level of the body, the rotating part is coupled on one side to the seismic mass, assembled on the body, by means of the rod, on the other side, to the leveling valve, and at the other end by means of springs and a rod is connected to the bogie. Said springs mean that with a maximum acceleration of the body, the maximum desired movement of the pneumatic spring (air spring) is obtained.
For the control by means of the lateral movement between the body and the bogie, no seismic mass is arranged since the actual body acts as the seismic mass. To that end the rotating part coupled to the bogie at one end is coupled to the body at another end by means of an additional rod and is coupled to the operating lever of the leveling valve of the pneumatic spring with another rod.

Description of the Drawings

Figures 1A and 1B show two states, on a straight route and curved route, respectively, of a conventional suspension by means of pneumatic springs with low-flow leveling valves, the response of which does not allow compensating the natural inclination of the vehicle.
Figures 2A to 2C show the different states, on a straight route, when entering the curve and rounding the curve, of a conventional suspension by means of pneumatic springs with high-flow leveling valves which allow partially compensating the natural inclination of the vehicle.
Figures 3A to 3C show the different states of a pneumatic tilting system according to the invention based on the control by means of the lateral acceleration of the bogie.
Figures 4A and 4B show respective embodiments of the mechanical device of the system of the invention.
Figures 5A to 5C show the different states of a pneumatic tilting system according to the invention based on the control by means of the lateral acceleration of the body.
Figures 6A to 6C show the different states of a pneumatic tilting system according to the invention based on the control by means of the lateral movement between the body and the bogie.
Figures 7A to 9B show the three embodiments of the invention implemented in a train set having the leveling valves in the bogie.

Detailed Description of the Invention

According to the present invention a pneumatic tilting system for railway vehicles is proposed which, by means of the incorporation of a mechanical device, allows performing controlled, robust and reliable tilting compared to conventional solutions.
The conventional suspension system of a train set is formed by pneumatic springs or air springs (1.1, 1.2) arranged between the bogie (2) and the body (4) of the vehicle, each of them having a low-flow leveling valve (3.1, 3.2) arranged in the body (4) and which is operated by means of a lever (5.1, 5.2) connected to the bogie (2) by means of a rod (6.1, 6.2), as can be seen in Figure 1A.
When the vehicle travels on a curve, due to the lateral acceleration (Ac), the body (4) moves laterally and tends to incline towards the outside of the curve with respect to the bogie (2), as shown in Figure 1B. When the body (4) inclines, the rod (6.2) operates the outer valve (3.2), such that the corresponding pneumatic spring (1.2) fills up, whereas the other rod (6.1) operates the other inner valve (3.1), emptying out the spring (1.1). In this case, as previously indicated, the compensation is not effective because the response of the valves is very slow.
Figures 2A to 2C show another conventional tilting system incorporating leveling valves (7.1, 7.2) with fast dynamics. When the train enters the curve due to the lateral acceleration (Ac), movement and relative rotation between the body (4) and the bogie (2) occurs. This rotation of the body (4) generates a difference in height (h1), which in this case is virtually corrected with the filling and emptying of the pneumatic springs (1.1, 1.2).
With this system, despite the fact that the deformation is virtually corrected, there is a height (h2) range which corresponds with the offset of the leveling valves (7.1, 7.2) which is not compensated, as can be seen in Figure 2C.
The tilting system object of the invention is based on the incorporation of a new rotating part (8.1, 8.2), together with a seismic mass (9.1, 9.2) for each pneumatic spring (1.1, 1.2), using a leveling valve (7.1, 7.2) with fast dynamics.
This new tilting system allows controlling the tilting depending on the lateral acceleration (Ac) at the level of the body (4), at the level of the bogie (2) or depending on the movement between the body (4) and the bogie (2), for which purpose different types of connections of the incorporated mechanical devices are provided.
In an embodiment with control of the lateral acceleration (Ac) at the level of the bogie (2), see Figures 3A to 3C, seismic masses (9.1, 9.2) are arranged in the bogie (2), joined to one of the ends of the rotating parts (8.1, 8.2), said rotating parts (8.1, 8.2) being joined in an articulated manner to the bogie (2) acting as a pendulum and coupled at another of their ends by means of rods (6.1, 6.2) to the levers (5.1, 5.2) of the leveling valves (7.1, 7.2) located in the body (4) of the vehicle.
In these conditions, when the train travels on a straight route, as shown in Figure 3A, the articulation between the rods (6.1, 6.2) joined to the rotating parts (8.1, 8.2) and the levers (5.1, 5.2) of the valves (7.1, 7.2) forms a 90° angle.
However, when the vehicle enters a curve, as shown in Figure 3B, the lateral acceleration (Ac) causes lateral deformation and makes the body (4) incline with respect to the bogie (2) a height (h3). Furthermore, the seismic masses (9.1, 9.2) move in the same direction as the lateral acceleration (Ac), making the rotating parts (8.1, 8.2) rotate and operate the levers (5.1, 5.2) of the leveling valves (7.1, 7.2), such that one of the pneumatic springs (1.1) empties and the other pneumatic spring (1.2) fills up.
As one of the springs (1.1) is emptying and the other one (1.2) filling up, the difference in heights between the body (4) and the bogie (2) on both sides is compensated, a difference of heights between both air springs (h4) finally being reached while balanced in a curve, which inclines the body (4) with respect to the bogie (2) in the direction opposite to the natural deformation, reducing the lateral acceleration that the passenger feels.
The mechanical device can be implemented in other manners, for example as shown in Figure 4A, where instead of the seismic mass (9.1, 9.2) there is a pendulum (10) arranged, joined to a rotating part (8) which is coupled through the rod (6) to the leveling valve (7). The movement of the pendulum is thus amplified, and as a result, the system takes up less space to achieve the same degree of tilting. Another embodiment of the mechanical device is shown in Figure 4B, in which instead of the seismic mass (9.1, 9.2) there is arranged a mass (11), and a spring (12) and a shock absorber (12.1), joined to the rotating part (8).
In the embodiment with control of the lateral acceleration (Ac) at the level of the body (4), see Figures 5A a 5C, the seismic masses (9.1, 9.2) are incorporated inside a closed housing (15) assembled in the body (4), and oil could be introduced in the housing (15) or a shock absorber of another type could be arranged to add damping to the system. In addition, the rotating parts (8.1, 8.2) are articulated to the leveling valves (7.1, 7.2) such that one of their ends is connected between springs (13 and 14) which are fixed to the bogie (2) by means of a rod, whereas the other end of the rotating parts (8.1, 8.2) is coupled to the respective seismic mass (9.1, 9.2) by means of a rod (6.1, 6.2).
In these conditions when the train enters a curve, the seismic masses (9.1, 9.2) move due to lateral acceleration (Ac), acting through the rods (6.1, 6.2) on the rotating parts (8.1, 8.2), which rotate compressing the springs (13 or 14), the pneumatic spring (1.1) located on the inside of the curve being emptied and the pneumatic spring (1.2) located on the outside of the curve being filled up, see Figure 5B.
While balanced in a curve, see Figure 5C, when the pneumatic springs (1.1, 1.2) have changed height, the springs (13 and 14) compensate the force of the seismic masses causing the movement thereof to their initial position and the closure of the leveling valves (7.1, 7.2), such that the body (4) of the train set tilts in the direction opposite to the lateral acceleration (Ac).
In this embodiment, the springs (13 and 14) limit the upward or downward movement of the body (4), said springs (13 and 14) having a travel equivalent to the maximum movement desired in one direction and in another.
In another embodiment, for the control by means of the lateral movement between the body (4) and the bogie (2), see Figures 6A to 6C, the rotating parts (8.1, 8.2) are articulated with respect to the bogie (2) and joined by means of their respective rods (6.1, 6.2) to the levers (5.1, 5.2) of the leveling valves (7.1, 7.2), and by means of other rods (16.1, 16.2) to the body (4), which in this case acts as the seismic mass of the previous embodiments.
With this arrangement, when the train enters a curve, the body (4) receives a lateral force caused by the lateral acceleration (Ac), moving it towards the outside of the curve, causing the movement of the rotating parts (8.1, 8.2) which operate the levers (5.1, 5.2) of the leveling valves (7.1, 7.2), making the outer pneumatic spring (1.2) fill up with air and the inner pneumatic spring (1.1) empty out, adding an additional superelevation of the track reducing the lateral acceleration that the passenger feels (see Figure 6C).
In this embodiment, the maximum and minimum tilting is limited by the lateral stops of the suspension and by the dimensions of the rotating parts (8.1, 8.2).
The embodiments shown above for lateral acceleration at the level of the bogie (2) and at the level of the body (4), and of lateral movement between the body (4) and the bogie (2), can also be implemented in vehicles which have the leveling valves (7.1, 7.2) in the bogie (2).
Figures 7A and 7B show the implementation of the solution with the valves located in the bogie (2) with the control by means of the lateral acceleration at the level of the body (4), where it is shown how the leveling valves (7.1, 7.2) are located in the bogie (2), whereby the rotating parts (8.1, 8.2) are arranged in the body (4) of the vehicle.
Figures 8A and 8B show the implementation of the embodiment for lateral acceleration at the level of the bogie (2), where it is shown how the leveling valves (7.1, 7.2) are located in the bogie (2) and the seismic masses (9.1, 9.2) are arranged in the bogie (2) of the vehicle.
Figures 9A and 9B show the implementation of the embodiment for lateral movement between the body (4) and the bogie (2) for a train set with the leveling valves (7.1, 7.2) in the bogie (2), the rotating parts (8.1, 8.2) in this embodiment being articulated to the body (4) of the vehicle, whereas the rods (16.1, 16.2) are joined to the bogie (2).

Claims

A controlled pneumatic tilting system in railway vehicles, of the type which use opening and shut-off valves for the pneumatic springs of the suspension to control the height of the body (4) with respect to the bogie (2), characterized in that the operation of the leveling valves (7.1, 7.2) of each of the pneumatic springs (1.1, 1.2) of the suspension incorporates a mechanical device formed by a rotating part (8.1, 8.2) coupled to a seismic mass (9.1, 9.2), such that when the vehicle enters a curve said mechanical devices act on the valves (7.1, 7.2), wherein a lateral movement of each seismic mass (9.1, 9.2) is transmitted, over each rotating part (8.1,8.2), to each valve (7.1,7.2), differentially operating the valves (7.1,7.2), and tilting the body (4) in the direction opposite to the lateral acceleration (Ac), controlling both the height of the springs and the tilt angle and as a result reduces the lateral acceleration that the passenger feels in a curve.
The controlled pneumatic tilting system in railway vehicles according to claim 1, characterized in that the height and the tilt angle are controlled by implementing the mechanical devices of the valves (7.1, 7.2) at the level of the bogie (2).
The controlled pneumatic tilting system in railway vehicles according to claims 1 and 2, characterized in that there are arranged in the mechanical devices implemented at the level of the bogie (2) seismic masses (9.1, 9.2) joined to rotating parts (8.1, 8.2), which in turn are joined in an articulated manner to the bogie (2) and are coupled at another of their ends by means of respective rods (6.1, 6.2) to the levers (5.1, 5.2) of the valves (7.1, 7.2) which are in the body (4) of the vehicle.
The controlled pneumatic tilting system in railway vehicles according to any one of the preceding claims, characterized in that the mechanical device can be formed by a pendulum (10) joined to a rotating part (8) coupled through a rod (6) to the respective leveling control valve (7).
The controlled pneumatic tilting system in railway vehicles according to any one of the preceding claims, characterized in that the mechanical device can be formed by a mass (11) and a spring (12) joined to a rotating part (8) coupled through a rod (6) to the respective leveling control valve (7).
The controlled pneumatic tilting system in railway vehicles according to claim 1, characterized in that the height and the tilt angle are controlled by implementing the mechanical devices of the valves (7.1, 7.2) at the level of the body (4) of the vehicle.
The controlled pneumatic tilting system in railway vehicles according to the claims 1 and 6, characterized in that in the mechanical devices implemented at the level of the body (4) the seismic masses (9.1, 9.2) are arranged inside a housing (15) arranged in the body (4) of the vehicle with oil or an additional shock absorber, the rotating parts (8.1, 8.2) being articulated in the leveling valves (7.1, 7.2) and connected with one of their ends between springs (13 and 14) which are fixed in the bogie (2) by means of a rod, whereas the other end of said rotating parts (8.1, 8.2) is coupled to the corresponding seismic mass (9.1, 9.2) by means of a respective rod (6.1, 6.2).
The controlled pneumatic tilting system in railway vehicles according to claim 1, characterized in that the height and the tilt angle are controlled by the movement between the body (4) and the bogie (2), the rotating parts (8.1, 8.2) being articulated with respect to the bogie (2) and joined by means of respective rods (6.1, 6.2) to the levers (5.1, 5.2) of the valves (7.1, 7.2) and by means of other rods (16) to the body (4) of the vehicle, which acts as the seismic mass.
The controlled pneumatic tilting system in railway vehicles according to any one of the previous claims, characterized in that the solutions for control of the lateral acceleration at the level of the bogie (2), at the level of the body (4) and of lateral movement between the body (4) and the bogie (2), can be implemented in train sets having their leveling valves (7) in the bogie (2) of the train set.