EP0655378B1 - Apparatus and method for steering the wheel sets of railway vehicles - Google Patents

Abstract

The chassis has the individual wheel set supported by a chassis frame (50) acted on by a spring elastic device (6), providing a restoring force opposing the movement of the chassis frame when travelling around a curved track section. The chassis frame is attached to a yoke (58) via linkages (61,61') allowing its movement relative to the yoke in both vertical and transverse directions, with impact buffers (68,68') limiting the transverse movement.

Description

The invention relates to a single-axle drive and a method for controlling a wheel set for a rail vehicle according to the top handle of claims 1 and 25 respectively.

It is known that a wheel set of a rail vehicle that has a corresponding Has profile of the wheel arches when cornering on a curved track can perform independent steering movement around a vertical axis. At a For example, a conical profile of the tread occurs on a track arch a roll radius difference between the inner and outer running circle, whereby a radial adjustment movement of the wheel set is caused.

For a favorable wear behavior, the lowest possible starting angle is between Wheel and rail worth striving for. For this purpose, the wheelset should be in its Freedom of movement around the vertical axis should be restricted as little as possible. In the case of a wheel set which is softly coupled to the vehicle in this way occurs during the run in a straight sine or wave course, which is inherently harmless. From one At a certain speed, however, the sinus run suddenly hits the dangerous one and wearing zigzag around. This speed limit is called critical Speed denotes, it essentially determines the highest permissible Speed of the vehicle with.

To counteract the zigzag run and a high limit speed too will achieve, as is known, a device for generating a restoring force, which acts against radial rotation of the wheelset. For example is the restoring force by at least one acting on the wheelset elastic resilient element exercised.

When designing trolleys that are suitable for both high speeds are, as well as have good sheet running properties (low wear) the following contradictory situation: For good sheet running properties with low wear, the wheelset should be softly coupled to the vehicle, i.e. the restoring force is low, however high speeds require one great restoring force.

A known approach provides that the steering deflection of the wheelset priority control is set, i.e. through a mechanical coupling of the Steering deflection of the wheel set with another of the radius of the curve dependent mechanical size. This size is e.g. the deflection angle between a bogie for storing two wheel sets and the body. The turning angle of the wheelset is not determined by the between the wheels and rail occurring forces, but mechanically due to purely geometric Conditions.

Einerseits sind sehr hohe Einstellgenauigkeiten bei der mechanischen Kopplung erforderlich, die im Betrieb nur mit hohem Aufwand erreicht werden können, andererseits können Drehgestellausdrehungen in einer Geraden aufgrund von Gleislagestörungen unerwünschte Radsatzauslenkungen und instabilen Lauf (Zickzacklauf) bewirken.

This solution has two major disadvantages:

On the one hand, very high setting accuracies are required for the mechanical coupling, which can only be achieved with great effort during operation, on the other hand, bogie bends in a straight line can cause unwanted wheel set deflections and unstable running (zigzag running) due to track position problems.

A positive control of a chassis for rail vehicles with mechanical or hydraulic coupling of the wheels is for example from DE-A-36 35 804 known.

CH-A-390 980 shows a control device for a single axis drive, at the control of the wheel set on the left and right of the swivel axis of the drive arranged gas-filled elastic bellows takes place in which while driving straight ahead the same medium pressure prevails. Before a left or right curve a recording device transmits a single signal via the respective sense of the curve following curve. Depending on the direction of the curve, one of the bellows with the pressure medium is applied the maximum pressure is applied and the other is emptied.

A device of the type mentioned is known from DE-C-882 562. Then a single-axis drive is also shown, in which a spring-elastic Device generates a restoring force against a steering deflection of the wheel set becomes. Furthermore, an actuator is shown in DE-C-882 562, which acts on the wheelset and that is controlled by a control or regulating device. Their input size is picked up by sensing elements arranged on the side of the rails, which determine the relative position between the wheelset and rails, depending The wheel set is positively controlled by this input variable.

A disadvantage of this forced steering using position-controlled control elements the high precision required when steering the wheelset gives way to the set deflection of the wheelset only slightly from the ideal value, so leads this leads to unfavorable rolling behavior and high wear.

The object of the invention compared to DE-C-882 562 is an improved To provide single-axis drive or method, which is essential when cornering with a lower accuracy must be controlled without the described Disadvantages of the chassis of DE-C-882 562 occur.

According to the invention this is 25 achieved by the features of the characterizing part of claim 1 and 25 respectively.

The restoring force can be set high in the device according to the invention, which ensures the desired stability of the vehicle running at a high limit speed is achieved. When cornering, depending on the radius of the track arch exerted a counterforce acting against the restoring force This gives the wheelset a pre-control effect. However, this means no forced control, since the angular position of the Wheelset still by the forces occurring between wheel and rail is set independently. The result is a very small run-up angle between Wheel and rail and therefore excellent wear behavior. The two contrary requirements of a high limit speed and good sheet running properties were thus almost from the device according to the invention ideally met.

To achieve an optimal pre-tax effect, the strength of the counterforce is approximate inversely proportional to the radius of the curve (or proportional for the curvature of the curve). This is the radius of the track curve detected by a corresponding device, for example by evaluating the Deflection angle of a bogie used to support two wheel sets. For the function of the device according to the invention, it is favorable if the counterforce in contrast to the restoring force is a path-independent force, i.e. it is independent from the deflection of the wheelset.

To set the strength of the counterforce, for example, at least one proportional Pressure control valve, a proportional pressure relief valve or pressure-controlled pump can be used. About instabilities with small deflections Avoiding in straight-ahead running is the one acting against the restoring force Counterforce preferably only from a certain threshold of the detected Radius of the circular arc exercised.

It is also conceivable to adjust the speed of the force increase by a suitable one Limit the circuit so that rapid changes in the manipulated variable (e.g. turning angle of the bogie) not to the same extent on the steering movements of the wheelset act, but the wheelset steering movements take place more slowly.

Abb. 1 ein nicht unter den Anspruch 1 fallendes Beispiel zur Illustration des Anwendungsgebietes mit zwei an einem Drehgestell gelagerten Radsätzen, welches die Steuerung der Radsätze mit Hilfe einer Einrichtung zur Erzeugung einer Gegenkraft und einer elektrohydraulischen Regeleinrichtung zeigt; Abb. 2 ein zweites Ausführungsbeispiel der elektrohydraulischen Regeleinrichtung; Abb. 3 ein Diagramm der Kennlinie der Rückstellkraft ohne (a) und in Kombination mit der Gegenkraft (b); Abb. 4 zu einer baulichen Einheit zusammengefaßte Einrichtungen zur Erzeugung der Rückstellkraft, sowie zur Erzeugung der Gegenkraft; Abb. 5 eine schematische Darstellung eines einzeln aufgehängten Radsatzes; Abb. 6 eine Draufsicht auf ein erfindungsgemäßes Einzelachslaufwerk; Abb. 7 die Ansicht des Fahrwerkes aus Abb. 6 von vorne; Abb. 8 dessen Seitenansicht; Abb. 9 eine schematische Abbildung eines Zentrierfederelementes und Abb. 10 dessen Kraft-Weg-Kennlinie.

Further details of the device according to the invention are subsequently discussed with reference to the drawings. In these is:

Fig. 1 is an example of the field of application with two wheel sets mounted on a bogie, which does not fall under claim 1, which shows the control of the wheel sets with the aid of a device for generating a counterforce and an electro-hydraulic control device; Fig. 2 shows a second embodiment of the electro-hydraulic control device; Fig. 3 is a diagram of the characteristic of the restoring force without (a) and in combination with the counterforce (b); Fig. 4 devices combined to form a structural unit for generating the restoring force and for generating the counterforce; Fig. 5 is a schematic representation of an individually suspended wheelset; Fig. 6 is a plan view of a single-axis drive according to the invention; Fig. 7 the view of the chassis from Fig. 6 from the front; Fig. 8 its side view; Fig. 9 is a schematic illustration of a centering spring element and Fig. 10 the force-displacement characteristic.

In Fig. 1 two wheel sets 1, 1 'rotatable about a vertical axis are shown at the two ends of a bogie that can also be rotated about a vertical axis 8 are stored. The wheel sets 1, 1 'consist of axles 2, the axle bearings 3 and the wheels 4, the tread 5 provided with a conical profile are, which leads to the described self-steering effect when traveling through an arc. The Wheel sets 1, 1 'are deflected by an angle β or their axle bearings 3 a distance S shifted.

Resilient elements, for example springs 6, act on the axle bearings 3 Exercise restoring force, which acts against a deflection β of the wheel sets. Means The devices 7 according to the invention can have a counterforce acting against the Restoring force acts.

The electro-hydraulic control device 20 consists of a hydraulic fluid reservoir 21, a pump 22, a pressure return 23, a throttle 24 and two electronically controlled proportional pressure regulating valves 12, 13, the outlet side of which Pressure is set by a voltage that the control device 11 issues.

When traveling on a curved track, the bogie 2 rotates relative to that Car body (not shown) through an angle α that is proportional to curvature of the track arch. With the help of a transducer 10, which in this embodiment essentially contains a potentiometer, the deflection angle α des Bogie converted into a control voltage U. The amount of this tension is proportional to the deflection angle α (and thus to the curvature of the curve) and her The sign depends on the direction of rotation.

Threshold elements 30, 31 subsequently check the magnitude and the sign of the voltage U. If U is above a certain threshold value U _o , the voltage U is switched through to the output of the threshold element 30. It is then amplified by the amplifier 32 and used to control the pressure control valve 12. As a result, the pistons of the cylinders 7 are acted upon by a pressure proportional to U via the hydraulic line 40.

In the opposite case, when U is below a threshold value -U _o , the pressure control valve 13 is controlled via the amplifier 33, whereby the pistons of the cylinders 7 are acted upon by a pressure proportional to U via the hydraulic line 41.

The pressure on the pistons of the cylinders 7 is always exerted in the manner that a force acts against the restoring force of the springs. In the case of the one shown in Fig. 1 Deflection of the bogie clockwise is the upper wheelset adjust clockwise by a certain angle β. The springs 6 practice against this deflection a restoring force. To apply a force against the restoring force, the left piston of the upper wheel set must be on its axis, the on the right-hand side with an appropriate pressure become.

If U is in the range between -U _o and U _o , both outputs of the threshold members 30, 31 are de-energized and the outputs of the pressure control valves are depressurized, so that no force is exerted on the pistons of the cylinders 7. This ensures stable straight running, even if there are small deflections of the bogie. If the outputs of the two threshold elements 30, 31 are de-energized, this also applies to the output of the OR gate 34. A switching element 35 then switches off the pump motor 22a after a predetermined time delay via a switch 36. The pump 22 thus only works when cornering.

An alternative embodiment of the electro-hydraulic control device 20 is shown in Fig. 2. The control voltage U controls two electronically controlled proportional pressure relief valves 112, 113 from Mannesmann Rexroth, type DBETE St / 200 624. In this case, only one inverter 111 is required to control the valves, which reverses the sign of the control voltage for the valve 113. The valves 112, 113 only respond to positive values of U, whereby the hydraulic line 140 or 141 to be pressurized is selected in connection with the inverter 111. The valves 112, 113 also have a setting for specifying a threshold value U _o for the voltage U, below which no pressure is exerted on the pistons. There is also the option of specifying a limit for the maximum rate of increase in pressure. This embodiment has the advantage over the control device from Fig. 1 that, at a control voltage U <U _o, no pressure is built up in the pump circuit, so that the pump can operate in an energetically favorable manner in idle mode.

The functionality of the device can be explained most easily with the help of Fig. 3. In Fig. 3a the dependence of the restoring force on the axle bearing displacement s (see Fig. 1) is drawn as a straight line F _x = c · S, with c the spring constant. The adhesion limit F _G between rail and wheels indicates the maximum size of the radial adjustment force due to the self-steering effect. The intersection of F _x and F _G determines the maximum axle bearing displacement S _m in a conventional axle control, which can be achieved during an arc travel against the restoring force. The ideal axle bearing shift, in which the steering deflection of the wheel set is optimally adapted to the radius of the track curve, can, however, be at a larger value S _i . Especially with hard springs with a large spring constant c, which allow high limit speeds, the track radius S _{m is} far below S _i with a small radius, so that a large run-up angle between wheel and rail results in unfavorable wear behavior.

Fig. 3b shows the conditions during the setup. The counterforce against the restoring force can be represented as a downward shift of the straight line F _x by a value F _y . F _y corresponds to the force with which the cylinders 7 (see Fig. 1) are applied. The size of F _y is chosen so that the shifted straight line F _x 'intersects the x-axis approximately at S _i . However, F _y does not have to be set very precisely, but can lie in a relatively large range, which is given by the fact that the intersection of F _x 'with the x-axis lies within the free adjustment range FE between S _i -S _m and S _i + S _m lies within which the wheelset can adjust itself automatically to the optimal steering deflection S _i .

Since S _{i is} proportional to the curvature of the track curve, F _y must also be approximately proportional to the curvature of the track curve, so that the x-axis intersection of F _x lies between S _i -S _m and S _i + S _m for each curve of the track curve. The proportionality constant of F _y is determined from the spring constant c of the return spring.

Another possible embodiment of the device is shown in Fig. 4 shown. In this are the facilities for generating the restoring force and combined to generate the counterforce to form a structural unit. To becomes a hydraulic or pneumatic piston 70 against the cylinder 71, in which it is guided, elastically clamped, for example in the manner shown with a spring 72. Via hydraulic lines 73, 74, the cylinder can be deflected when the Pressure against the force of the spring.

In order to use the invention, two sets of wheels are not now in common stored on a bogie. As shown in Fig. 5, this takes place with individually stored Wheelsets 1 the attachment of devices 7 that have a counterforce exert against the restoring force of resilient elements 6. The facility for In this case, detection of the radius of the curve cannot of course determine the deflection angle of a bogie, but has to work in a different way. For example, the angle between two car bodies could be used to record the Pull in the curve radius. Furthermore, auxiliary wheels or optical ones are used for this purpose Facilities conceivable and possible. Furthermore, it is conceivable and possible, also with individually mounted wheels devices for exerting a restoring force and a Apply the counterforce against the restoring force in the same way as for wheel sets.

All conceivable resilient devices can be used to exert the restoring force are used, such as rubber bellows or pneumatic springs. To exercise the counterforce, all force generating elements come into question, the one in the generate significant location-independent force, for example hydraulic cylinders, Pneumatic cylinders or air bellows.

A single-axis drive according to the invention with one individually in a chassis frame 50 guided wheel set 51 is shown in Figs. 6-8. The wheel set 51 can be driven by a motor 52 via a gear 53 and a clutch 54 his. The wheels 59, 59 'of the wheel set 51 are via a wheel set shaft 65 rigidly connected. The wheelset 51 is supported in the axle bearings 55 (see Fig. 8), via a primary suspension 56 with the chassis frame 50 are connected. The undercarriage frame 50 is provided with a secondary suspension Air springs 57 is formed, connected to the car body 60. Furthermore, the Chassis frame 50 is articulated to a guide crossmember or a yoke 58. This connection is made by two pairs of links 61 and 61 ', which are rotatable about vertical axes and which are on the one hand on the chassis frame 50, on the other hand are articulated on the yoke 58. The yoke 58 in turn is over Trailing arms 62, 62 'are articulated to carriage-fixed guide brackets 63, 63'. If the joints of the trailing arms 62, 62 'are formed by ball joints, are displacements of the guide cross member 58 with respect to the car body not only possible in the horizontal, but also in the vertical direction.

Because of the articulated connection of the chassis frame 50 with the guide cross member 58 and due to the elasticity of the air springs 57 are steering movements of the Chassis frame 50 possible about a vertical axis. The primary suspension between Wheelset 51 and chassis frame 50, however, has such a hard in the longitudinal direction Spring constant on that almost no steering movements of the wheelset 51st compared to the chassis frame 50 are possible. Against that when driving over a track curve caused due to the difference in wheel radius of the wheels 59, 59 ' Steering movement of the chassis frame 50 acts the restoring force of the resilient Element 6, which on the one hand on the chassis frame 50 and on the other attacks on the yoke 58 and is arranged transversely to the direction of travel. For application a counterforce acting against the restoring force is a force-controlled actuator 7 provided. With this, in turn, as previously with reference to Fig. 3 force feedforward control has been carried out, d. H. the characteristic the resilient element 6 is shifted during an arc travel, whereby a optimized driving behavior of the chassis is achieved.

When accelerating and braking, longitudinal forces are exerted on the chassis, which can be received by the trailing arms 62, 62 '. Furthermore is one Pitch support 69 is provided which rotates the undercarriage frame 50 by one Cross axis prevented. An anti-roll support, not shown, can also be used in an analogous manner be provided, the rotation of the chassis frame 50 by a Longitudinal axis prevented. Transverse movements of the chassis frame 50 are from carriage-fixed guide brackets 63, 63 'attached transverse stop buffers 68, 68' limited or cushioned.

The resilient element 6 is advantageously formed by a centering spring element, shown in Fig. 9. This has a housing 80 with stops 80a fixed to the housing, against which stop rings 83 rest in the idle state. Between the stop rings 83 a spring 81 is placed under prestress. The rod 84 passing through the housing 80 has two flanges 85 within the housing 80 at a distance from the stops 80a of the housing 80, between which the stop rings 83 lie. The behavior of the centering spring element in the event of a force exerted on the rod 84 is described by the characteristic curve shown in FIG. 10. With a force that is below a certain threshold value F _s , there is no displacement of the rod 84, since the spring 81 is under a prestress. Only when the force is above the threshold value F _s is there a displacement of the rod 84, the rod 84 again returning to the centered starting position after the force has been exerted. By using such a centering spring element, the chassis frame can be centered with only a single spring element 6 and the characteristic curve of the centering spring element shown in FIG. 10 leads to an improvement in the stability of the drive according to the invention when driving straight ahead.

A sensor 67, for example an inductive displacement sensor, which detects the actual value of the steering deflection, could detect a malfunction, for example in the Hydraulic system can be used.

The single-axle running gear shown in Fig. 6 - 8 is extremely comfortable to drive, because it perfectly fulfills the diverse requirements for a drive. Even if the hydraulic system fails, safety is guaranteed due to the self-centering of the wheel set 51 by means of the spring element 6. An advantage over conventional bogie is the possible saving of axles what leads to a reduction in costs.

Claims (27)

1. A single-axle running gear for a railway vehicle in which each chassis frame which is mounted rotatably with respect to the railway vehicle has only one respective single wheel set, wherein there are provided a resilient device (6) for producing a return force against steering deflection of the wheel set (1, 1', 51) and in addition a control member (7) which is coupled to the wheel set (1, 1', 51) and which is actuated by a control or regulating device (20), and also a device (10) for detecting the radius of the track curve, characterised in that provided as the control or regulating device (20) is a control or regulating device (20) which at the control member (7) sets a force parameter as a control or regulating parameter, wherein the force parameter which is controlled or regulated at the control member (7) and which acts in opposition to the return force of the resilient device (6) is dependent on the radius of the track curve.
2. A single-axle running gear according to claim 1 characterised in that the force parameter which is set at the control member (7) is set to be approximately inversely proportional to the radius of the track curve.
3. A single-axle running gear according to claim 1 or claim 2 characterised in that the force-regulated control member (7) has at least one hydraulic cylinder.
4. A single-axle running gear according to claim 1 or claim 2 characterised in that the force-regulated control member (7) includes at least one pneumatically acting element, preferably a pneumatic cylinder or an air spring bellows.
5. A single-axle running gear according to one of claims 1 to 4 characterised in that the force-regulated control member (7) engages the two lateral ends of the wheel set (1, 1'), laterally outside the wheels (4), for example at the axle bearing housing (3).
6. A single-axle running gear according to one of claims 1 to 5 characterised in that the control or regulating device for adjusting the force parameter has proportional pressure regulating valves (12, 13).
7. A single-axle running gear according to one of claims 1 to 5 characterised in that the control or regulating device for adjusting the force parameter has proportional pressure limiting valves (112, 113).
8. A single-axle running gear according to one of claims 1 to 5 characterised in that the control or regulating device for adjusting the force parameter has a pressure-regulated pump.
9. A single-axle running gear according to one of claims 1 to 8 characterised in that the force-regulated control member is acted upon by the control or regulating device only above a given threshold value in respect of the detected curvature of the track curve.
10. A single-axle running gear according to one of claims 1 to 9 characterised in that there are provided means, for example an electronic circuit, which limit upwardly the maximum rate of rise of the force parameter which is set by the control or regulating device.
11. A single-axle running gear according to one of claims 1 to 10 characterised in that the resilient device (6) as known per se is a spring which preferably engages the axle bearing.
12. A single-axle running gear according to one of claims 1 to 11 characterised in that the resilient device (6) for producing the return force and the force-regulated control member (7) are combined to form a structural unit.
13. A single-axle running gear according to claim 12 characterised in that the structural unit includes a cylinder (71) in which a displaceable piston (70) can be acted upon on the one hand by at least one spring (72) and on the other hand, preferably from both sides, by means of a pressure medium.
14. A single-axle running gear according to one of claims 1 to 13 characterised in that the device for producing the return force has a self-centering spring element which includes a spring which is under a prestress.
15. A single-axle running gear according to one of claims 1 to 14 characterised in that there is provided a sensor (67) for detecting the actual value of the steering deflection of the wheel set (1, 1', 51).
16. A single-axle running gear according to one of claims 1 to 15 characterised in that a respective single wheel set (51) is supported in a steerable chassis frame (50), wherein the device (6) for producing the return force which is dependent on the steering deflection and the force-regulated control member (7) for producing the counteracting force which acts in opposition to the return force engage the chassis frame.
17. A single-axle running gear according to claim 16 characterised in that the device (6) for producing the return force and/or the force-regulated control member (7) for producing the counteracting force are arranged transversely with respect to the direction of travel.
18. A single-axle running gear according to one of claims 16 or 17 characterised in that there is provided a yoke (58) which is displaceable in the vertical direction and in a transverse direction and which is pivotably connected to the car body, wherein the chassis frame (50) is connected to the yoke (58) steerably about a vertical axis.
19. A single-axle running gear according to claim 18 characterised in that the yoke (58) is pivotably connected to the car body (60) by way of longitudinal links (62, 62') to carry the longitudinal forces which occur.
20. A single-axle running gear according to claim 19 characterised in that the longitudinal links (62, 62') are mounted in the yoke (58) and in the car body (60) by means of ball joints.
21. A single-axle running gear according to one of claims 18 to 20 characterised in that the movement of the chassis frame (50) is limited in the transverse direction by transverse abutment buffers (68, 68') which are arranged on guide brackets (63, 63') which are fixed with respect to the car.
22. A single-axle running gear according to one of claims 18 to 21 characterised in that the device (6) for producing the return force and the force-regulated control member (7) for producing the counteracting force engage the chassis frame (50) on the one hand and the yoke (58) on the other hand.
23. A single-axle running gear according to one of claims 18 to 22 characterised in that the connection between the chassis frame (50) and the yoke (58) is formed by links (61, 61') which are pivotably mounted to the chassis frame (50) on the one hand and to the yoke (58) on the other hand, the links (61, 61') being mounted rotatably about vertical axes.
24. A single-axle running gear according to one of claims 18 to 23 characterised in that the wheel set (51) is driven by a motor (52) which is preferably arranged on the chassis frame (50).
25. A method of controlling a wheel set (1, 1', 51) of a single-axle running gear of a railway vehicle in which each chassis frame which is mounted rotatably with respect to the railway vehicle has only one respective single wheel set, wherein there are provided a resilient device (6) for producing a return force against steering deflection of the wheel set (1, 1', 51) and in addition a control member (7) which is coupled to the wheel set (1, 1', 51) and which is actuated by a control or regulating device (20), and also a device (10) for detecting the radius of the track curve, characterised in that the control or regulating device (20) sets at the control member (7) a force parameter as a control or regulating parameter which acts against the return force of the resilient device (6) and is dependent on the radius of the track curve.
26. A method according to claim 25 characterised in that the force parameter is controlled or regulated in dependence on the radius of the track curve in such a way that the superimposition of the return force (F_x) of the resilient device (6) and the force parameter which is controlled or regulated at the control member (7) results in a resultant force (F_x') which disappears approximately at the ideal axle bearing displacement (s_i) at which the steering deflection of the wheel set is optimally adapted to the radius of the track curve.
27. A method according to claim 26 characterised in that the axle bearing displacement (s) at which the resultant force (F_x') disappears is in the free setting range (FE) about the ideal axle bearing displacement (s_i).

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