RAIL VEHICLE

Abstract

The invention relates to a rail vehicle comprising a chassis provided with individual wheels which are respectively mounted on axle carriers in such a way that they can pivot in the horizontal direction about a vertical steering axis. Said rail vehicle also comprises a steering actuator associated with each wheel, for adjusting a pre-determined steering angle about the vertical steering axis, the wheels (1) of the axles being respectively mounted in such a way that they can be pivoted in the vertical direction about a horizontal camber axis (S) and can be acted upon by means of a camber actuator (7) in order to adjust a pre-determined camber angle (αS).

Description

The invention relates to a rail vehicle comprising a chassis provided with individual wheels which are respectively mounted on axle carriers in such a way that they can pivot in the horizontal direction about a vertical steering axis. Said rail vehicle also comprises a steering actuator associated with each wheel, for adjusting a pre-determined steering angle about the vertical steering axis.

DE 40 40 303 A1 discloses a rail vehicle with a chassis, of which individual wheels are mounted on an axle carrier, which is mounted for pivoting in the horizontal direction about a vertical steering axis. The wheels cooperate with a steering actuator, so that the wheels during travel can be adjusted to a predetermined steering angle. The rail vehicle includes an independent-wheel running gear and can be actively steered by actuation of the steering actuator on the wheels.

The disadvantage of this known rail vehicle is that the track guidance and track steering during negotiation of curves or, as the case may be, passive switch plates, is not reliably taken into consideration and in unfavorable circumstances could lead to derailing of the rail vehicles.

It is thus the task of the present invention to further develop a rail vehicle of this type such that a safe, reliable and robust rail guidance thereof is ensured.

In combination with the pre-characterizing portion of claim 1, the solution of this task is solved thereby, that the wheels of the axle are respectively mounted in such a way that they can be pivoted in the vertical direction about a horizontal camber axis and can be actuated by means of a camber actuator for adjusting the predetermined camber angle.

The particular advantage of the invention is comprised therein, that a reliable and robust rail guidance and rail steering is made possible, which is independent of the coefficient of friction of a wheel-rail-contact point. If the coefficient of friction drops due to weather conditions, such as ice or foliage on the rails, then the rail vehicle speed need not be reduced in the curve.

It is the basic idea of the invention to decouple the dependence of the rail guidance or piloting friction. In accordance with the invention this occurs thereby, that the camber of the wheels is changed or, as the case may be, that this is tilted sideways to the vehicle longitudinal axis. Since the rails have a hemispherical cross-sectional profile, the wheels can support themselves thereupon.

In accordance with a preferred embodiment of the invention, a camber actuator is controlled in such a manner, that the wheel is oriented in a central position or camber position, in that exclusively normal forces are transmitted in the wheel contact point. The wheel is thus tilted sideways in such a manner that no frictional forces exist in the transverse direction. Thereby transverse forces occurring during negotiation of a curve can be completely supported via the sideways forces on the contoured sides. The friction at the wheel-to-rail-contact point can be reduced. An absence of slippage in the transverse direction can be ensured.

According to a further development of the invention the wheel is mounted via a four-bar linkage to the chassis. Advantageously thereby undesired movements of the chassis can be avoided. Thereby the space between the instantaneous center of rotation and the wheel-to-rail contact point can be kept small.

According to a further development of the invention the wheel is mounted to the chassis via a king-pin steering.

According to a particular embodiment of the invention one fixed camber axis per wheel can be provided, which is oriented perpendicular to the steering axis and parallel to the vehicle longitudinal direction.

According to a second embodiment of the invention the camber axis can be variable depending on the camber angle. Therein the wheel is coupled to the axle carrier via a cross linkage or control arm or wishbone.

Further advantages of the invention can be seen from the dependent claims.

Illustrative embodiments of the invention are explained in the following on the basis of the figures.

There is shown:

FIG. 1a: a schematic vertical section through a chassis of a rail vehicle according to a first embodiment,

FIG. 1b: a horizontal section through the chassis according to the first embodiment,

FIG. 2a: a schematic vertical section through a chassis according to a second embodiment,

FIG. 2b: a horizontal section through the chassis of the second embodiment, and

FIG. 3: a schematic representation of a camber position of the wheel.

A rail vehicle is moved along the rails 4 by a not shown drive and/or braking unit in the vehicle in the longitudinal direction (transverse to the image plane according to FIG. 1a) with rolling of the wheels 1.

The wheels 1 are a component of a chassis 2, which is provided in a not-shown rail carriage body.

The chassis 2 includes elongate axle carriers 3, upon the opposite end areas of which the wheels 1 are respectively individually mounted.

For adjusting to a predetermined steering angle α_L about a vertical steering axis V a steering actuator 5 is provided. The steering actuator 5 is mounted between an arm 6 and the not-shown wheel hub provided in the wheel 1. The vertical steering axis V extends in a central radial plane M_R of the wheel 1.

The steering actuator 5 is controlled via a not shown control unit in such a manner, that the wheel 1 is adjusted according to such a steering angle α_L, that the wheels 1 are guided along one of the curve radius r set by the rails 4.

For setting a predetermined angle α_F of the wheel 1 a camber actuator 7 is provided, which is provided between the axle arm 8 and the axle carrier 3.

According to a first embodiment of the invention as shown in FIGS. 1a and 1b the wheel 1 is pivotable about a fixed horizontal camber axis S, which runs at a vertical height, which is set below a horizontal axle plane of the wheel 1. The camber actuator 7 engages above the horizontal axial plane of the wheel 1.

The camber axis S is provided perpendicular to the vertical longitudinal axis V and in the vehicle longitudinal direction. The horizontal camber axis S and the vertical longitudinal axis V intersect in the central radial plane M_R of the wheel 1.

The camber actuator 7 is controlled via a not shown control unit in such a manner, that the wheel 1 is pivoted, depending upon the longitudinal angle α_L, in such a way about the camber angle α_S sideways of the central position in a camber position, so that at the wheel contact point P exclusively normal forces F_N are transmitted. As can be seen from the camber position of the wheel 1 shown in FIG. 3, the camber angle α_S of the wheel 1 corresponds to the angle α_F, which is locked in or implemented on the one hand by the vertical force F_V and on the other hand by the force F_R resulting from the combination of the vertical force F_V and the transverse force F_Q.

The camber actuator 7 can be controlled during negotiating of a curve in such a manner, that the camber angle α_S is computed from the relationship

$\tan {\alpha }_S=\frac{v^2}{\mathrm{rg}},$

• • wherein v is the vehicle speed, r is the steering radius and g the gravitational acceleration.

According to a second embodiment of the invention as shown in FIGS. 2a and 2b the camber actuator 7 is connected via a twin control arm or suspension arm 9 of a control arm or suspension arm unit 10 with the wheel 1 in an articulated linkage. The same components or, as the case may be, component functions are provided with the same reference numbers.

The control arm unit 10 is comprised of two twin control arms 9, 9′, which extend from a common axle arm 11 on both sides of the central radial plane M_R of the wheel 1. By adjusting the wheel 1 about the camber angle α_S a tilting of the wheel 1 about a variable camber axis S occurs. This is preferably situated below a horizontal axial plane of the wheel 1. The twin control arms 9 or, as the case may be, 9′ exhibit respectively parallel control arm axis 12.

The steering actuator 5 is mounted between a steering rod 13 and the not shown wheel hub provided in the wheel 1.

The wheel 1 can be mounted in the chassis 2 via a four-bar linkage. Preferably the wheel 1 is mounted in the chassis 2 via a king-pin steering.

The vertical steering axis V preferably runs in the central radial plane M_R of the wheel 1.

Claims

1. A rail vehicle with a chassis provided with individual wheels which are respectively mounted on axle carriers, which are mounted in such a way that they can pivot in the horizontal direction about a vertical steering axis, and a steering actuator associated with each respective wheel for adjusting a predetermined steering angle about the vertical steering axis, thereby characterized, that the wheels (1) of the axle respectively are mounted pivotable in the vertical direction about a horizontal camber axis (S) and by means of a camber actuator (7) actuatable for adjusting a predetermined camber angle (αS).

2. The rail vehicle according to claim 1, wherein the camber actuator (7) is coupled with the wheel (1) and wherein the camber actuator (7) is controlled in such a manner, that the wheel (1) is oriented in a centered or a chamfered position, in which exclusively normal forces are transmitted at the wheel contact point (P).

3. The rail vehicle according to claim 1, wherein the camber actuator (7) is controlled in such a manner, that the camber angle (αS) is the same as an acute angle (αF), which is comprised of the sum of a vertical force (FV) running in the vertical direction and a transverse force (FQ) running in the horizontal direction and extends or arranges on the one hand the resulting force (FR) acting upon the wheel contact point (P) of the rail and on the other hand on the vertical force (FV).

4. The rail vehicle according to claim 1, wherein the camber actuator (7) is controlled in such a manner, that the camber angle (αS) of the wheel 1 is adjusted according to the relationship tan   α S = v 2 rg _, wherein v is the speed of the rail vehicle, r the steering radius according to the curve being negotiated by the rail vehicle, and g is gravitational acceleration.

5. The rail vehicle according to claim 1, wherein the wheel (1) is mounted on the chassis (2) via a four-bar linkage.

6. The rail vehicle according to claim 1, wherein the wheel (1) is mounted via a king pin steering in the chassis (2).

7. The rail vehicle according to claim 1, wherein the control unit acts on a camber actuator (7) engaging the wheel (1) via an articulated linkage, in such a manner, that the wheel (1), depending upon the steering angle (αL), is pivoted out of a central position (M) by camber angle (αS) in the support axis (S).

8. The rail vehicle according to claim 1, wherein the camber actuator (7) is linked directly to the wheel (1), in such a manner, that the wheel (1) is pivotable about a fixed camber axis (S), which runs approximately the height of one of the areas of the wheel (1) close to the rail.

9. The rail vehicle according to claim 1, wherein the camber actuator (7) is linked to the wheel (1) via a twin control arm (9, 9′) of a control arm unit, wherein the twin control arms (9, 9′) in a central or normal position of the camber actuator (7) run symmetric to a central radial plane (RM).

10. The rail vehicle according to claim 1, wherein the vertical steering axis (V) extends or runs in the central radial plane (MR) of the wheel (1).