EP1228937B1 - Device for guiding the axles of a rail vehicle - Google Patents

Abstract

The invention relates to a device for guiding the axles of a rail vehicle having at least one articulation-actuator mounted between two elements of the bogie of said vehicle that are movable relative to one another, said articulation-actuator comprising: an outer casing (1) connected to one of the mobile elements; an inner axle (2) connected to the axle of the mobile elements; an elastomer assembly (3) connecting the outer case (1) to the inner axle (2); two sealed chambers, one inner (6) and one outer (5) chamber, which are located between the outer casing (1) and the inner axle (2) and which are filled with fluid, the inner chamber (6) being located on the side of the mobile elements and the outer chamber (5) being located on the side of the other mobile element; two conduits (7) communicating said chambers (5) (6) with an outer fluid distributing device. The invention can be used in railroad vehicles.

Description

The present invention relates to the primary suspension of a railway vehicle, and to the devices for adjusting the positioning relative to the chassis of the axle bogie mounted.

PRIOR STATE OF THE ART

• les ressorts et amortisseurs verticaux pour la répartition équilibrée de la charge verticale sur les roues d'un même bogie ;
• un dispositif de guidage qui agit sur un plan horizontal (X,Y) formé par les axes longitudinal (X) et transversal (Y) par rapport à la marche du véhicule et qui, en plus d'assurer la connexion entre le bogie et les essieux, a pour mission de guider les essieux sur la voie, de transmettre les efforts de traction et de freinage et de stabiliser la marche du véhicule.

The suspension of a railway vehicle is installed on the bogie and comprises two stages, primary and secondary, the primary suspension being connected between the axles and the chassis of the bogie. The primary suspension stage includes two types of elements:

• vertical springs and shock absorbers for balanced distribution of the vertical load on the wheels of the same bogie;
• a guide device which acts on a horizontal plane (X, Y) formed by the longitudinal (X) and transverse (Y) axes with respect to the running of the vehicle and which, in addition to ensuring the connection between the bogie and the axles, its mission is to guide the axles on the track, to transmit the traction and braking forces and to stabilize the running of the vehicle.

To ensure the running stability of the rail vehicle at high speed, it is necessary to have a device for guidance or articulation having high values of longitudinal stiffness and transverse stiffness by relative to the direction of travel, especially as the speed traffic is great. On the other hand, when the vehicle driving in a bend, when taking curves, you must a guide device having a low value of rigidity, in particular for longitudinal rigidity, so that the axles are free to guide themselves correctly and so that they can take a radial position. The better stiffness characteristics longitudinal and transverse guide devices known, are obtained by jointly using elastomer and metal elements. Rigidity values required in one direction or in several at the same time are obtained according to the geometric shape of the device and the distribution of elastomer and metal parts on the device. The stiffness values are generally preset according to the design of the bogie and we can therefore expect that even if good walking stability is guaranteed, the curve behavior will not be optimal and vice versa.

An axle guiding device of a railway vehicle must be required to have variable longitudinal stiffness enabling it to acquire the optimum value under any operating condition and as a function of the frequency of excitation to which it is subjected: low frequency movements such as those generated when the axle seeks to be placed in a position radial to the curve, the guide must respond with a module with low rigidity; and in the event of high frequency movements such as those generated on the axle when it is traveling at high speed, the guide must have a high rigidity module. However, the variable rigidity characteristic thus determined of the known devices is almost independent of the frequency of the excitations to which the bogie is subjected. We know of applications in which the axle guidance works with two stiffness values, one low without its activation and the other high when it is activated when the vehicle is traveling at speeds higher than a preset limit value. An example of this type of guidance is disclosed in publication EP-A-360783 .

To obtain a guide device whose longitudinal rigidity is both sensitive to the speed of the vehicle and the frequency of excitation, we know the use of joints made in the form of a cylindrical sleeve provided with two internal chambers of material elastomer filled with hydraulic fluid. An example of this type of articulation with variable rigidity is that disclosed in EP-A-360783 but this articulation is connected in a vertical position inside the vertical spring of the primary suspension of the mounted axle. Although this known articulation is of variable rigidity, as it is coupled to the vertical spring, it cannot by itself absorb vibrations in the longitudinal and transverse directions and must therefore be mounted with an additional bush provided with a sliding surface for the decoupling of the movements of the vertical suspension. However, the use of a connection with the sliding surfaces of the articulations on the suspension causes either play which is detrimental to the stability of walking at high speed, or the bending of its parts damaging the socket of the articulation. The articulation of the above-mentioned document constitutes a “passive” control articulation with variable rigidity but does not dampen vibrations effectively since its operation depends on the state of the sliding surfaces. In addition, its fluid chambers are sealed without external fluid supply.

During the movement of the vehicle in a curve, an articulation with “active” control is required to orient the axles in a radial position, ie each of them must remain perpendicular to the respective tangent of the arc of the curve. An example of articulation for an “active” control system is one of those disclosed in EP-A-870664 which has a cylindrical sleeve connected in horizontal arrangement between the axle box and the chassis of the bogie. The known articulation is constructed in the form of a socket provided with a central guide rod and two internal chambers filled with a fluid, each of them having an individual external conduit for the supply and the reciprocal extraction of the fluid from an external distribution valve, as a function of time. The “active” joint mentioned works as a hydraulic cylinder or cylinder of the control system for the guidance or automatic adjustment of the axles of the bogie when cornering.

STATEMENT OF THE INVENTION

The object of the present invention is to provide a bogie guiding device for a railway vehicle, including an elastic joint for control passive and active control of the suspension of the bogie, which is connected horizontally between the box axle and the bogie chassis, as defined in claim 1.

An advantage of the guide device according to the invention is that it manages to combine in the bogie suspension the effects specific to a cylinder hydraulic and elastic spring. Suspension bogie primary based on the proposed joint provides optimal vehicle behavior when taking a turn and when traveling in a straight line.

The joint includes a cylindrical metal socket horizontally connected to the axle box and a rod of the joint passing through the bushing which is connected to the bogie chassis. The socket has two cavities watertight forming two chambers filled with a fluid hydraulic, arranged symmetrically on both sides of the joint rod in the longitudinal direction of the market. Thus, the rod can move with the chassis of the bogie in the diametrical direction of the sleeve, namely the direction longitudinal of the walk. These two fluid cavities of the joint are in communication through an internal conduit narrow, where the passage of fluid from one chamber to another is dynamically dependent on the frequency of the excitation.

The hydraulic elastic joint is designed to be mounted on the articulated axle box of the mounted axle without the need for sliding elements between them, and therefore without friction elements, thus avoiding any play in the stability of the walking of the vehicle and the risk of bulging and causing the joint to break.
The articulation is sensitive to the speed of the vehicle and to the frequency of movements or excitation of the bogie, by adapting its longitudinal stiffness values to the condition of the vehicle running, in a straight line at high speed or almost static in a curve, and because of its horizontal arrangement with respect to the bogie, it is decoupled from its vertical movement and acts only in the two axes of the horizontal plane (X, Y) while also providing a combined effect of rigidity and damping of vibrations in the longitudinal direction.

The articulation provides an axle guide according to a increasing stiffness modulus with increasing frequency of excitation. Namely, the joint is duct with a higher rigidity module for high excitation frequencies and has a modulus of very low rigidity for low frequency movements. Thanks to the production of vulcanized elastomer walls on the articulation rod and the dimensions of the conduit of intercommunication of the cavities, the passage of the fluid of a cavity to another is controlled by the own deformation of walls, which is proportional to the stress longitudinal of the joint, and by the diameter and the length of intercommunication path. As the frequency of stress increases, the passage of fluid from one room to another decreases and the elastic walls of cavities provide more resistance to deformation, and by therefore the stiffness modulus of the joint increases. In high frequency movements, the fluid cavities seek to hold the rod the articulation fixed to the chassis of the bogie, thus giving to the device great longitudinal rigidity.

The joint can also be used as an element elastic of the active guidance system of the bogie. This articulation provides longitudinal rigidity to the guide axle and allows controlled longitudinal movement of the articulation rod relative to the fixed socket to the axle box. This last effect is obtained by properly filling / draining the fluid from both chambers of the joint from the outside. For his functioning as a cylinder, filling / emptying of cavities is controlled by a distribution valve of external fluid, through an individual conduit of each cavity, in response to an axle guide unit.

DESCRIPTION OF THE DRAWINGS

Figure 1 is a sectional view of a joint of the guide device according to the invention.

Figure 2 is a sectional view of the joint of the Figure 1 along line II-II.

Figure 3 shows the articulation of Figure 2 in regime work dynamics. The joint rod has been moved relative to the outer sleeve reducing the volume of one room and increasing that of the other bedroom.

Figures 4 and 5 are different views showing the connection to the bogie of a vehicle of the articulation of the figure 1.

Figure 6 is a schematic representation of the device guide on a bogie having two axles mounted, provided joints like Figure 1.

Figure 7 is a schematic representation of the device guide of Figure 6 with the two axles mounted performing a turn in a turn.

DESCRIPTION OF A PREFERENTIAL EMBODIMENT OF THE INVENTION

With regard to Figures 1-7, an embodiment of the guiding device 1,8,9,10,12 for axles mounted on a rail vehicle, includes several joints 1 hydraulic elastics whose structure is shown on Figures 1-3 and which are each connected in horizontal arrangement between the chassis 8 of the bogie and a box 9 of articulated axles 9 (Figures 4-7).

Referring to Figures 1-5, the structure of a articulation 1 of guide comprises a bush 1a cylindrical with a metal carcass 16 which is fixed to a box 9 of axles, and a rod 2 of the articulation which is connected to a fork-shaped attachment 8 of the bogie frame (Fig. 5) Rod 2 crosses a wide opening 1b at each end of the socket, which allows an eccentric displacement "x" of the rod 2 by the articulation towards one or the other wall 16 of the sleeve 1a, when it follows the relative movements of the chassis 8 in the longitudinal direction X with respect to the axles mounted 12 and also in the transverse direction Y. For the vertical suspension Z, a spring 17 is mounted on the bogie (fig. 4) arranged vertically on each axle box 9 and decoupled from the guide device.

The socket has two cavities inside 5.6 filled with fluid, forming two chambers, one of each side of the rod 2 relative to the diameter of the sleeve 1a, connected together through an internal conduit 4, and the hydraulic fluid can therefore flow from one chamber to the other. The cavities 5,6 have been molded and soaked in a body 3 elastomer and are respectively formed from the walls 5a, 6a vulcanized power stations around the rod 2 in contact with her. The cavities 5,6 can deform in the direction X (fig. 3), thus moving rod 2 by relative to the carcass 16 of the socket. The displacement "x" relative between rod 2 and socket la is notably more pronounced in bogie 8 movements at low excitation frequency, effective transmission of the fluid occurring from one cavity 5 to another cavity 6 or vice vice versa, depending on the sign of displacement "x" of the axle 12 required. As these cavities 5.6 are completely filled of a fluid, the controlled passage of fluid from a cavity 5.6 to the other through a narrow calibrated conduit 4 gives articulation 1 a damping effect which, in combination with that provided by the walls 5a, 6a made of elastomer deformable, makes the joint acquire a modulus of adequate longitudinal rigidity which will be for movements at high frequency a high rigidity module and for quasi static or low frequency movements a module of low rigidity.

As an example of embodiment of the joint 1 where the rod 2 has a diameter of 60 to 120 mm, the internal conduit 4 of communication between the cavities 5 and 6 of fluid (fig. 1) is a perforation with a diameter "Dp" of 0.5 to 6 mm, the latter being carried out on the rod 2 as a function of the amortization sought by joint 1 on the plan horizontal X, Y. The length of the perforated conduit 4 is "Lp" equivalent to the diameter of the rod 2. During the vulcanization of the elastomer body 3, the walls 5a, 6a of the cavities respectively have an opening 18.19 connection with each end of conduit 4. Such a internal intercommunication channel 4 is advantageous over a tube or rigid pipe type external conduit incorporated in the socket of the joint, since it is not exposed to impacts, deformations or friction caused by external agents and does not require connections by junctions responsible for brittleness and fluid losses compromising reliability.

Figures 6 and 7 show a guide device 1,8,9,10,12 with four identical articulations 1 operating as an articulation-jack 10 for automatic adjustment of the two axles mounted 12 in a radial position at the curve. Each articulation 1 is connected to each axle box 9 of a bogie with two axles mounted 12. In an example of construction, each side member 8 of a two-axle bogie 12 includes two cylinder joints 10 in series, supplied with hydraulic fluid in a controlled manner by a valve 13 distribution or similar common, from a line hydraulic supply P (pressure line), T (return to the tank). Each of the cavities 5.6 has respectively a supply pipe 7 from the valve 13, produced according to an axial perforation inside the rod 2 and which is connected to an opening 20, 21 corresponding on the walls 5a, 6a of the cavities. The conduit 7 for each cavity 5.6 is also used initially for filling the cavities 5,6 with fluid.

The articulation-cylinder 1 behaves both as a hydraulic cylinder 10 and as an elastic spring 11, 15 with longitudinal stiffness 15 and transverse stiffness 11. In if the active guidance system fails, such as the total or partial loss of hydraulic fluid from device, the joint 1 functions as a spring to stiffness Kx1 in the longitudinal direction and Ky1 in the direction transverse.

When the articulation 1 behaves like a hydraulic cylinder 10 (fig. 6-7), the guide device supplied by two distribution valves 13 ensures such a relative displacement “d” between the axle box 9 and the chassis 8 that the axles 12 are positioned in the radial direction to the curve. If we designate by R the radius of the curve of the track, by S a half-wheelbase of the chassis of the bogie 8 - in the longitudinal direction X - and by Lk1 the half-distance between the articulations-jacks 10 in the direction transverse Y, the relative displacements "d" made by each joint are d = S / R.Lk1 where “d” represents the individual relative displacement of each articulation 1, of sign + (elongation) on those of the bogie spar 8 outside the curve and of sign- (shortening) on those of the spar of bogie 8 inside the curve. This type of control device control is called "movement control". The action of the guiding devices by means of a "force control" is also possible, where the jack-joints 10 each exert a force "f" between the bushing la and its rod 2 on each individual joint 1, the forces exerted during the circulation in curve being f = S / R. Lk1. Kx1. K where the force “f” has a sign + when it is of compression and the articulation seeks to lengthen and a sign-when it is of traction, the articulation seeks to compress, “Kx1” the value of longitudinal rigidity 15 and “K” a proportionality factor close to unity, depending on the speed, the uncompensated lateral acceleration and the radius R of the curve.

Claims (5)

1. Device for guiding the axles of a rail vehicle bogie, comprising at least one articulation-actuator (1) of the elastic-hydraulic type connected according to a horizontal axis (plane X,Y) between an axle-box (9) of each mounted axle (12) and the bogie frame (8), the articulation (1) being operated by an active control of the primary suspension of bogie (8) for the radial positioning of the axles (12) relative to a curve (R) in the track and acting as a hydraulic cylinder (10), the articulation-actuator (1) comprising a cylindrical bushing (1a) containing an elastomer body (3) which provide two cavities (5,6) filled with hydraulic fluid, the body (3) encircling a central stem (2) connected to the frame of the bogie (8), the cavities (5,6) being supplied by way of a respective internal conduit (7) from an external distribution source (13,P,T) for displacement of the stem (2) in the longitudinal direction X of travel either to one side or to the diametrically opposing side of the bushing (1a), characterised in that the articulation (1,10) has an intermediate conduit (4) of a determinated cross section between the two cavities (5,6) for the controlled transmission of the fluid between them and the aforesaid longitudinal displacements (x) of the stem (2) relative to the articulation producing the deformation of the cavities (5,6), the controlled flow of the fluid from one to another taking place by way of the intermediate conduit (4) in such a way as to provide a damping effect on the movements of the bogie in the longitudinal direction (X) and to obtain the adjustment of the rigidity values (11,15) of the suspension of the bogie (8) corresponding to both running conditions of the vehicle on straight track and on curves in function of the excitation frequency.
2. Device for guiding the axles of a bogie according to claim 1, wherein said elastomer cavities (5,6) are made by vulcanizing with a wall (5a,6a) around the stem (2) in contact with it, said wall (5b,6b) being deformable by means of the variation in the pressure of the fluid inside the cavity (5,6).
3. Device for guiding the axles of a bogie according to claim 1, wherein said internal conduit (4) for the controlled transmission of fluid between both cavities (5,5) of an articulation-actuator (1), comprises a hole (4) drilled through the articulation stem (2), with a calibrated diameter (Dp) and a predetermined length (Lp) in function of the damping sought for the longitudinal movement (X).
4. Device for guiding the axles of a bogie according to any of the preceding claims, wherein said internal conduit (4) for the transmission of fluid between both cavities (5,6) of an articulation-actuator (1) has a diameter (Dp) of 0.5-6 mm and a length (Lp) of 60-120 mm.
5. Device for guiding the axles of a bogie according to claim 1, wherein said conduits (4) for the supply of external fluid to each cavity (5,6) of an articulation-actuator (1) comprise a hole (7) machined axially through the articulation-actuator stem (2).

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