EP1029764A2 - Suspension for a railway vehicle - Google Patents

Abstract

The system has spring elements with hydraulic units having working chambers with adjustable volumes. The working chambers of two or more hydraulic units (2a,b,c,d) are connected to a common suspension gas container (8a) via a synchronizer unit (19a). The unit has a hollow chamber divided by a piston into three or more independent part chambers. One of these is connected to a gas container, at least two further chambers are each connected to the working chamber of a hydraulic unit.

Description

The invention relates to a suspension for a rail vehicle, in which in the wheel area between the wheel axle and a frame as primary suspension and / or between the frame and a spring element is provided to the vehicle body as secondary suspension, which a hydraulic unit with a working cavity, the volume of which is opposed by two movable end pieces is changeable, and has a spring gas container which by a movable separator is divided into a gas space and a hydraulic space, the working cavity is connected to the hydraulic room and these two rooms with a liquid are filled, but the gas space is filled with a gas.

The demands placed on rail vehicles have been strong in recent years gone up. Based on market trends, it can be seen that these requirements in the future will continue to rise. On the one hand, it is required that the vehicles are used to transport ever higher payloads are suitable, on the other hand, if possible, the dead weight of the vehicles are kept low. There is a general desire for high driving safety, and especially in vehicles for the transportation of people even after a high level of driving comfort. Especially with underground and trams, but also with passenger trains increasingly sought a construction method in which the wagons' entries and exits have a small vertical distance to the platform or to the street to make it comfortable To allow boarding and alighting, even for elderly or frail people, for example. However, this design requires the vehicle body to be arranged as low as possible above the wheels or the wheel axles, which means that the chassis is only less Space is available.

• hoher Fahrkomfort,
• hohe Fahrsicherheit,
• hohe Nutzlast bei geringem Eigengewicht, sowie
• eine niedrige Bauweise

führen häufig zu Konflikten bei der Auslegung der Federung für Schienenfahrzeuge, da die notwendigen Federkennwerte bei den zur Verfügung stehenden Bauräumen mit herkömmlichen Federelementen oftmals nicht mehr realisierbar sind. Häufig wird daher versucht, gewisse Anforderungen an die Fahrzeugeigenschaften dadurch zu erfüllen, dass hinsichtlich der Federung Kompromisse eingegangen werden. So kann durch eine Erhöhung des Federweges die Feder weich ausgebildet werden, dies führt allerdings unter hoher Belastung zu einem Einsinken des Fahrzeugkastens in Bezug auf das Höhenniveau der Räder bzw. der Radachsen sowie einer Tendenz zu starken Wankbewegungen. Weiters ist es natürlich auch von Nachteil, dass eine Erhöhung des Federweges mit einem größeren Bedarf an Bauraum verbunden ist.All these requirements for modern rail vehicles, such as

• high driving comfort,
• high driving safety,
• high payload with low weight, as well
• a low construction

often lead to conflicts in the design of the suspension for rail vehicles, since the necessary spring parameters can often no longer be achieved with conventional spring elements in the available installation spaces. It is therefore often attempted to meet certain vehicle properties requirements by compromising on the suspension. Thus, the spring can be made soft by increasing the spring travel, but this leads to a sinking of the vehicle body under high load in relation to the height level of the wheels or the wheel axles and a tendency to strong roll movements. Furthermore, it is of course also disadvantageous that an increase in the spring travel is associated with a greater need for installation space.

Often, the requirements for vehicle properties can also be increased by increasing the Operating loads of the springs used up to close to the permissible load limits be fulfilled. However, this is from a safety point of view and also in terms of to a maintenance vulnerability resulting from these high operational demands unfavorable due to material fatigue. The use of rubber springs is also common Considered, however, rubber springs have many known disadvantages, such as sensitivity against temperature, humidity, light, chemicals, oil etc. on.

For example, EP 0 568 042 A1 describes a spring element of the type mentioned at the beginning for a Bogie, in which hydropneumatic spring elements, consisting of cylinder and Pistons with assigned liquid and gas volumes are provided. In the spring elements at least part of the liquid volume is provided, and the gas volume can be arranged in the spring elements, or there are gas accumulators on the spring elements connected as external elements, with a part of the liquid volume in the gas storage and the gas volume is included. By refilling or draining the liquid the height of the spring elements are regulated, the spring elements being connected to one another Lines communicate.

A disadvantage of this suspension system is that it can roll during practical operation. and tilting movements of a rail vehicle can not compensate for what with a high Derailment risk.

Furthermore, DE 196 51 138 A1 describes a suspension consisting of two connected in parallel Spring systems with three springs arranged parallel to each other, one Spring is designed as a hydropneumatic spring, which is a bellows made of elastomeric material has a support plate with the upper part using fastening means a rolling piston connects, the hydropneumatic spring of one system with the hydropneumatic spring of the second spring system by means of an overflow channel pressure equalizing connected is. A second spring is provided around each hydropneumatic spring, which extends from the support plate to the base of the rolling piston, one third spring is installed in the rolling piston.

The large installation volume, which is due to the low construction of the rail vehicle makes installation impossible, proves to be a major disadvantage of this spring system.

DE 42 34 523 A1 describes a method for controlling the level and the inclination of a Car body for vehicles, especially for rail vehicles presented, at least a hydropneumatically controlled suspension damping system is provided. At The gas volume in a hydropneumatic suspension accumulator becomes a load increase (HPF memory) compressed, the reduction in gas volume by feeding a corresponding amount of hydraulic fluid is compensated. In contrast, must a reduction in the vehicle load, which leads to an expansion of the gas in the HPF memory leads to the increase in gas volume by draining hydraulic fluid the circle be balanced.

With this system, the complex electronic control proves to be unfavorable which also increases the susceptibility to malfunctions and which high maintenance and Installation costs conditional.

DE 907 150 C describes a suspension of vehicles in which the wheel load is above a liquid pressure medium is transferred to several air cushions connected in series, which gradually come into effect, the air cushions being filled with air Bubbles are formed from an elastic material and a wall part as a sealing surface is trained.

The disadvantage of this suspension is that the air cushion at high loads, such as in the practical operation of a rail vehicle occur, are damaged or destroyed can, which affects the spring action or is completely lost.

In US 3,439,630 A a hydropneumatic spring device is described, which consists of hydraulic cylinder units, one between individual spring elements Pipeline is provided which cooperates with a pressure receptacle is partially filled with gas, which can be compressed by the liquid. For support the hydropneumatic spring device are made of further helical springs Metal provided. The presence of additional metal springs prevents space-saving, arrangement of the spring elements adapted to the structural conditions of the rail vehicle.

US 4,245,563 A describes a combination of helical metal springs and one hydropneumatic suspension, the nested and partially open cylinders has, wherein a liquid exchange is possible between the cylinders. Like the US 3 439 630 A, the large installation volume is also a disadvantage here.

EP 0 321 324 A1 presents a hydropneumatic suspension which has a cylinder has, which is connected by a support arm to a wheel, an am Car body attached piston is provided, the axis of which is guided in a cylinder bore and that is connected to a hydropneumatic pressure accumulator. This However, suspension does not meet the requirements for rail vehicles because it is due to their very special embodiment can only be used for motor vehicles.

Furthermore, all the above-mentioned embodiments of spring elements and spring systems together, that they roll and tilt movements of a Rail vehicle can not compensate, which is associated with a high risk of derailment is.

With the known suspension systems for rail vehicles, the required Stability properties with only a small installation space available will be realized.

It is therefore an object of the invention to provide a spring system which has a compact, Space-saving design allows, and at the same time is able to roll and / or pitch movements to spring the vehicle without additional stabilizing devices, the Suspension of these movements regardless of diving movements of the vehicle and thus regardless of the vertical rigidity of the spring elements.

This task is based on a spring system of the type mentioned solved that the working cavity of two or more hydraulic units via a synchronizing unit communicates with a common spring gas container.

It has proven to be useful if the working cavity of two or more hydraulic units is connected to a common spring gas container via lines, the working cavity of two or more hydraulic units via a synchronizing unit communicates with a common spring gas container. Connecting the Working cavities of two or more hydraulic units with a common spring gas tank brings advantages in terms of the necessary installation space, since for several hydraulic units only a spring gas container is necessary. However, it is particularly useful if these working cavities are also connected to one another via a synchronizing unit stand. For hydraulic units which have a synchronization unit with a common one The spring gas container is connected, even if the load is unequal Even deflection possible, which stabilizes unwanted movements of the vehicle, such as swaying or nodding regardless of diving movements of the Vehicle is possible without additional necessary roll stabilizers, etc.

In an expedient embodiment it is provided that the synchronization unit has a cavity, which by a freely displaceable piston in at least three separate sub-cavities are separated, at least one of these sub-cavities is connected to a spring gas container, and at least two of the other partial cavities are each connected to at least one working cavity of a spring element.

In order to stabilize a vehicle against swaying, it is advantageous if the working cavities of hydraulic units on opposite sides of a wheel axle a common Have spring gas containers. It proves to be particularly favorable if the working cavities of hydraulic units on opposite sides of a wheel axle by means of a Synchronizing unit are connected to a common spring gas container.

It is for rail vehicles that only experience weak starting or deceleration forces favorable if the working cavities of hydraulic units on one side of the vehicle a common line are in contact and the two lines of the respective vehicle side are connected to a spring gas container via a common synchronization unit, because in this structurally simple way, swaying regardless of diving movements can be sprung.

In order to stabilize pitching movements in addition to rolling movements, it is necessary to that the working cavities of two hydraulic units each, which on diagonally opposite Wheels are arranged, each via a synchronization unit with a common one Spring gas containers are connected. This remains the case with this interconnection of the working cavities Chassis additionally twistable, which is in view of frequently occurring twists of rails is cheap.

It can also be advantageous if each working cavity of a hydraulic unit has exactly one Has spring gas container. With this arrangement, all wheels of a chassis or one Vehicle are damped separately, a roll or pitch stabilization is the vehicle but not possible without additional stabilization devices.

Fig. 1 ein Federelement,

Fig. 2 schematisch den Einbau eines Federelements in der Primärfederung eines Schienenfahrzeuges, weiters die

Fig. 3 bis Fig. 5 verschiedene Möglichkeiten zum Verbinden der Arbeitshohlräume mehrerer Federelemente, und

Fig. 6 einen schematischen Aufbau einer Synchronisiereinheit.

In the following the invention together with further advantageous embodiments is shown in the drawing. In this show

1 is a spring element,

Fig. 2 shows schematically the installation of a spring element in the primary suspension of a rail vehicle, further the

Fig. 3 to Fig. 5 different ways of connecting the working cavities of several spring elements, and

Fig. 6 shows a schematic structure of a synchronization unit.

The spring element 1 shown in FIG. 1 has a hydraulic unit 2 with two end pieces 3a and 3b, which are sealingly connected to one another via a bellows 4. Through the two End pieces 3a and 3b and the bellows 4, a working cavity 5 is limited, which accordingly the distance between the end pieces 3a and 3b can be changed. This is bellows 4 generally around a bellows with a predefined rolling contour that does not move, has sliding seals, which in terms of the tightness of the working cavity 5 of Advantage is. When the spring element 1 is loaded, the rolling bellows 4 rolls according to the Reduction of the distance between the two end pieces 3a and 3b on what is generally used as a rolling cylinder trained end piece 3b. The working cavity 5 is connected via a line 7 a spring gas container 8 in connection. In the advantageous embodiment shown here is the connection 6 of the line 7 to the working cavity 5 in the end piece 3a of the spring element 1 is formed. The spring gas container 8 is usually a membrane formed part 9 divided into a gas space 10 and a hydraulic space 11. The Hydraulic chamber 11, the line 7 and the working cavity 5 are incompressible Fluid, the hydraulic fluid, the gas space 10, however, filled with a gas. Finally 1 one can find an end stop 12 designed as a rubber buffer on the inside of the end piece 3b recognize which for the case of tip strokes or as an emergency spring for the case is thought that the spring mechanism due to, for example, the loss of Hydraulic fluid fails.

A hydraulic fluid, generally an oil, is chosen as the working medium, since fluids can be used under high pressures and thereby the spring element with respect of the necessary space can be kept small. That is why gas is considered as Spring medium chosen because it shows a progressive behavior, and thus an optimal use the travel is guaranteed.

2 shows a chassis frame 13, a wheelset bearing 14 and a wheel 15 of a rail vehicle shown. The installation of a spring element 1 according to FIG. 1 is schematic between the chassis frame 13 and the wheelset bearing 14 indicated. With an expedient Embodiment is the spring element 1, although it only has to transmit pressure forces in usually both with the chassis frame 13 and with the housing of the wheelset bearing 14 screwed.

3 to 5 show roughly schematic spring systems in which the hydraulic units 2a-2d of spring elements 1 attached in the area of wheels 15 of a rail vehicle are, the working cavities of the hydraulic units logically interconnected are. The embodiment in which each working cavity has one is not shown has its own spring gas container, so the hydraulic units are not coupled to each other are. In this embodiment, springing of each wheel is possible separately, however can not pitch or roll independently of diving movements without additional Stabilizing device are suspended.

In detail, Fig. 3 shows a spring system in which a rolling movement of the vehicle is largely suppressed by the fact that the working cavities of two hydraulic units 2a and 2b, which in the area of wheels 15 on opposite sides of an axis are attached, via lines 16a and 16b and a synchronization unit 19a to one common spring gas container 8a are coupled. The synchronization unit 19a, its mode of operation is discussed in detail below, the task falls to - in In this case, two - work cavities to couple so that a compression of the one spring element immediately to deflect the spring element coupled to it or exactly taken to compress the interconnected hydraulic units 2a and 2b leads, whereby a roll motion is avoided. In order to cushion roll movements efficiently, is of course this pairing of opposite hydraulic units on necessary for each axis.

4 also shows a spring system for roll stabilization of a rail vehicle. In this embodiment, the working cavities are hydraulic units 2a and 2d and 2b and 2c of a vehicle side via a common line 17a and 17b connected with each other. However, the hydraulic units on one side are not above one Synchronizing unit in contact with each other. On the other hand, there are those coupled with each other Hydraulic units of a vehicle side with the coupled hydraulic units of the other side of the vehicle via a synchronization unit 19a with a common spring gas container 8a in contact. By simply connecting the working cavities of four hydraulic units 2a - 2d roll stabilization of the vehicle is achieved. However this roll stabilization with only one synchronization unit 19a only for vehicles in which low driving and braking forces are effective, suitable because of a pitching movement Embodiment is approved unsprung. An interconnection of the working cavities can be used accordingly 3 and 4, also for rail vehicles with more than two Axes are applied.

A problem for rail vehicles is that track twists occur along the route. If the suspension is too stiff, this usually relieves the pressure on one of the wheels of the undercarriage, which may lead to derailment if the wheel is relieved too much can come. This problem can be solved with the interconnection shown in FIG Working cavities can be encountered by hydraulic units. In this embodiment hydraulic units 2a and 2c and 2b are diagonally opposite one another and 2d via lines 18a, 18c and 18b, 18d and via a synchronization unit 19a, 19b coupled to a common spring gas container 8a. With this interconnection of the working cavities on the one hand, the cushioning of roll and pitch movements is possible, on the other hand but the vehicle or the chassis is also twistable, making a too strong Wheel relief regardless of the selected spring stiffness and therefore independent of the Suspension of diving movements can be prevented.

Finally, with reference to FIG. 6, the principle of operation for a synchronization unit 19 is as shown was already mentioned in FIGS. 3 to 5. 6 is a synchronization unit 19 shown for two working volumes of spring elements, the following considerations but naturally also apply to more if the synchronization unit is designed accordingly as two working volumes.

As can be seen from Fig. 6, a cavity 20 by a freely movable Piston 21 separated into three independent sub-cavities 22-24. The subareas 22 and 23 are connected via lines 25 and 26 to the working cavities of two hydraulic units, Subarea 24 via a line 27 to the hydraulic chamber of a spring gas container in connection. Both the hydraulic units and the spring gas tank are not here shown. A compression of the two end pieces 3a caused by a force effect and 3b of a hydraulic unit 2 as in FIG. 1 leads to the volume displaced thereby flows into a partial cavity, for example partial cavity 22 of the synchronizing unit 19. As a result, the piston 21 corresponding to the displaced volume in Area 22 is shifted and a reduction in volume in area 24, the Hydraulic fluid via line 27 into the connected hydraulic chamber of the spring gas container flows, and leads to an increase in volume in the area 23. By the Larger available volumes in area 23 result in an afterflow of hydraulic fluid from the working cavity of that hydraulic unit, which via the Line 26 is connected to the synchronization unit 19, and thus to a corresponding one Compression of this spring element or the hydraulic unit, although the external force on this hydraulic unit is less than on the line 25 with the synchronization unit 19 connected hydraulic unit.

With this structurally simple synchronization unit 19, the working cavities of two or more hydraulic units are coupled together so that a uniform Compression of all spring elements is possible despite different loads. By suitable Interconnecting the working cavities is therefore independent of pitch and / or roll stabilization of the vertical rigidity of the spring elements possible, furthermore there are no additional ones mechanical stabilization devices necessary.

The mode of operation of the synchronization unit described here can of course, as already mentioned, also on several working cavities of several spring elements or hydraulic units be expanded.

The various connection options for hydraulic units in the range of Wheels are mounted here, mainly using two-axle vehicles or Bogies explained because this arrangement is most common in rail vehicles is. However, the considerations made can easily be applied to rail vehicles with three and more axes are transferred and apply there analogously.

It should not go unmentioned that it can be provided that the liquid flows in the To dampen spring elements and lines using throttling devices. With that the Installation of additional dampers independent of the springs lapsed, which has advantages in With regard to the small space available, it is less expensive and contributes to a weight reduction of the rail vehicle.

Furthermore, level control by means of a pump and height regulator is provided, via which achieves an unchangeable height of the vehicle body regardless of the load can be.

Claims (6)

Suspension for a rail vehicle in which a spring element is provided in the area of wheels between the wheel axle and a frame as primary suspension and / or between the frame and the vehicle body as secondary suspension, which has a hydraulic unit (2) with a working cavity (5), the Volume can be changed by two mutually movable end pieces (3a, 3b), and has a spring gas container (8) which is divided by a movable separating part (9) into a gas space (10) and a hydraulic space (11), the working cavity (5 ) is connected to the hydraulic space (11) and these two spaces (5, 11) are filled with a liquid, but the gas space (10) is filled with a gas, characterized in that the working cavity is made up of two or more hydraulic units (2a, 2b, 2c, 2d) is connected to a common spring gas container (8a) via a synchronizing unit (19, 19a, 19b). Suspension according to claim 1, characterized in that the synchronizing unit (19) has a cavity (20) which is separated by a freely displaceable piston (21) into at least three mutually independent partial cavities (22-24), at least one of these partial cavities (24 ) is connected to a spring gas container, and at least two of the other partial cavities (22, 23) are each connected to at least one working cavity of a spring element. Suspension according to claim 1, characterized in that the working cavities of hydraulic units (2a, 2b) on opposite sides of a wheel axle are connected to a common spring gas container (8a) by means of a synchronizing unit (19a). (Fig. 3) Suspension according to claim 1, characterized in that the working cavities of hydraulic units (2a, 2d; 2b, 2c) on one side of the vehicle are in contact via a common line (17a; 17b) and the two lines (17a; 17b) on the respective side of the vehicle via one common synchronization unit (19a) are connected to a spring gas container (8a). (Fig.4) Suspension according to claim 1, characterized in that the working cavities of two hydraulic units (2a, 2c; 2b, 2d), which are arranged on diagonally opposite wheels (15), each have a synchronizing unit (19a; 19b) with a common spring gas container ( 8a) are connected. (Fig. 5) Suspension according to claim 1, characterized in that each working cavity (5) of a hydraulic unit (2) has exactly one spring gas container (8).

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