Braking system for a rail vehicle and method for engaging a parking brake of a rail vehicle

Abstract

The invention relates to a braking system (B) for a rail vehicle, comprising: a brake cylinder (1) to which a braking device (8) is operatively connected, wherein the braking device (8) is suitable for braking a wheel (R) of a rail vehicle, wherein the brake cylinder comprises a pressure chamber (1a); a closed-loop control device (6) for a service brake pressure; an open-loop control device (7) for a parking brake pressure; a valve device (4) which is suitable for connecting either the closed-loop control device (6) for a service brake pressure or the open-loop control device (7) for a parking brake pressure to the pressure chamber (1a) of the brake cylinder (1); a locking device (2) which is suitable, in a locked state, for securing the position of the braking device (8) from being released and, in a released state, has no influence on the position of the braking device (8), wherein the parking brake pressure is independent of the service brake pressure which is regulated by the closed-loop control device (6) for a service brake pressure. In this way, a parking brake can be produced easily, safely and cost-effectively.

Description

[0001] Braking system for a rail vehicle and method for engaging a parking brake of a rail vehicle

[0002] DESCRIPTION

[0003] The present invention relates to a braking system for rail vehicles in which, in addition to a service brake function, a parking brake function or

[0004] Parking brake function is present. Furthermore, the present invention relates to a method for engaging a parking brake of a rail vehicle.

[0005] Rail vehicles, such as passenger coaches, are equipped with a service brake, which can be used to slow a rail vehicle or a train of rail vehicles while in motion, as well as a parking brake, which can be applied when the rail vehicle or train of rail vehicles is to be parked, i.e., shut down. This can prevent the carriages from rolling away, particularly on inclined tracks (e.g., due to a mountain or hill).

[0006] Document WO 2017 / 149244 A1 is known from the prior art. This document discloses a braking system for a rail vehicle, which, among other things, includes a parking brake. The parking brake includes a locking device that is movable relative to the brake body for acting on the brake piston and can assume a first position (locked position) and a second position (unlocked position).

[0007] In the prior art, an internal pressure path is generally used for the control of the service brake and the parking brake. However, the service brake must fundamentally meet completely different requirements than the parking brake. The service brake should be easily controllable, smooth, and adjustable in steps. A parking brake control with only one pressure path, in which the service brake and the parking brake are applied together, cannot meet certain safety requirements. Therefore, it is an object of the present invention to provide a safe parking brake for a rail vehicle that can be implemented simply and cost-effectively.

[0008] This object is achieved by a braking system according to claim 1 and a method for engaging a parking brake according to claim 8. Further advantageous embodiments of the present invention are the subject of the dependent claims.

[0009] A braking system according to the invention comprises: a brake cylinder, with which a braking device is operatively connected, the braking device being adapted to brake a wheel of a rail vehicle, the brake cylinder having a pressure chamber; a regulating device for a service brake pressure; a control device for a parking brake pressure; a valve device adapted to connect either the regulating device for a service brake pressure or the control device for a parking brake pressure to the pressure chamber of the brake cylinder;a locking device adapted to fix the position of the braking device against release in a locked state and to have no influence on the position of the braking device in a released state, wherein the parking brake pressure (controlled by the control device) is independent of the service brake pressure regulated by the service brake pressure control device;

[0010] The parking brake function can be integrated into the brake cylinder, is lightweight, and requires minimal installation space. Furthermore, no additional braking force-generating elements are required.

[0011] The position of the braking device is fixed in the locked state to prevent it from being released - i.e. the braking device cannot be released, i.e. moved away from the wheel. However, it is possible for the braking device to be pushed further towards the wheel, for example to compensate for possible thermal shrinkage of the wheel or its components. In the released state, the position of the braking device is not influenced by the locking device. The parking brake can also be applied safely and independently of the service brake pressure. This means that two independent braking functions are possible, which can be safely switched between using the valve device. This allows SafePark braking to be applied safely. Because no separate parking brake cylinder is required, fewer components are involved. This leads to greater robustness, increased reliability and therefore increased availability.

[0012] The system according to the invention is interface-compatible with conventional parking brake systems with spring brake cylinders, ie the parking brake function can be easily integrated into existing systems.

[0013] This ensures that the parking brake pressure is independent of the service brake pressure regulated by the service brake pressure control device. This ensures a reliable separation between parking brake pressure and service brake pressure.

[0014] Preferably, the locking device can be engaged by a locking spring and released pneumatically again, more preferably by the control device for a parking brake pressure. This means that the locking device can be brought into the locked state by a spring, but can also be released pneumatically again.

[0015] Preferably, the parking brake pressure control device is adapted to control a parking brake pressure as well as a release pressure for the locking device. This means that a parking brake pressure control device has two different connections that can control pressure at different times. It is important, however, that a pressure level is preset, i.e., the parking brake pressure is preset to a certain pressure. The release pressure for the locking device can be variable. Limiting or regulating this is not necessary. This allows the control system to be as simple as possible.

[0016] Preferably, the locking device is integrated into the brake cylinder. This minimizes the required number of components, and the space requirement can also be minimized accordingly. Preferably, the locking device comprises an extendable device and an engagement device, and the extendable device is adapted to engage with the engagement device when locked. Thus, the parking brake can be implemented easily and without the need for complex assemblies.

[0017] Further preferably, the brake cylinder has a piston crown, and the piston crown of the brake cylinder is connected to the brake device via a connecting device, and the engagement device is preferably provided on the connecting device. This solution also allows the locking device to be provided in the brake cylinder, and fewer additional and, furthermore, no complicated components are required.

[0018] Preferably, the valve device is pneumatically switchable.

[0019] Further preferably, the valve device is a piston valve, and the valve device further preferably comprises a switching device. Such a configuration is simple and reliable, and the switching device can be used to switch the piston valve so that either only the parking brake pressure (controlled) or only the service brake pressure (regulated) is connected to the pressure chamber of the brake cylinder. A piston valve is robust and easy to integrate.

[0020] A method according to the invention for engaging a parking brake of a rail vehicle with a braking system as described above comprises the following steps: a) switching the valve device so that the pressure chamber of the brake cylinder is connected to the control device for the parking brake pressure; b) actuating the locking device to release the position of the braking device.

[0021] The two steps are triggered in the control system by a valve whose control logic is similar to that used in conventional systems. This allows the use of identical control logic to that used in conventional systems, which is a significant advantage for vehicle control. Furthermore, switching between the service brake and parking brake is easy, and the system is small, lightweight, compact, safe, highly available, and independent of other components. The parking brake pressure can be adjusted to suit the specific vehicle and requirements. Even if the service brake control fails, the parking brake can still be engaged.

[0022] Further preferably, the method comprises the following steps: c) venting the pressure chamber of the brake cylinder.

[0023] This can also occur through leaks.

[0024] The locking device fixes the position of the braking device and ensures that the parking brake is maintained even if pressure escapes (from the brake cylinder), so that vehicles can be parked safely.

[0025] In the following, preferred embodiments of the present invention are explained in more detail with the aid of the accompanying figures:

[0026] Fig. 1 shows a schematic sketch of a braking system according to the invention.

[0027] Fig. 2 shows a detailed view of a braking system according to the invention.

[0028] Fig. 3 shows a detailed view of the extendable piston device (part of the locking device).

[0029] Fig. 1 shows a braking system B according to the invention. A regulating device 6 for the service brake pressure and a control device 7 for the parking brake pressure are connected to a pressure vessel 3. Different, completely independent pressures can therefore be set by the regulating device 6 for the service brake pressure and the control device 7 for the parking brake pressure. The control device 7 for the parking brake pressure is directly connected to a locking device 2. The control device 7 for the parking brake pressure can therefore bring the locking device 2 into the locked or unlocked state. Another output of the control device 7 for the parking brake pressure is further connected to a valve device 4, which in turn is connected to a switching device 5. The valve device 4 can, for example, be a piston valve.One input of the valve is connected to the parking brake pressure control device 7, and another input is connected to the service brake pressure control device 6. One output is connected to the brake cylinder 1. The switching device 5 allows both inputs to be switched, so that the brake cylinder is connected either only to the pressure output by the service brake pressure control device 6 or to the pressure output by the parking brake pressure control device 7.

[0030] Fig. 2 shows a more detailed view of a braking system B according to the invention. Here, a brake cylinder 1 is shown. In this, a piston head 1c is preloaded with a spring 1b. On the other side of the piston head 1c is a pressure chamber 1a. The piston head 1c is connected by means of a connecting device 9 to a braking device 8 (designed as a brake pad in Fig. 2), which can be pressed against a wheel R of a rail vehicle. On the connecting device 9, an engagement device 2b is provided, with which an extendable piston device 2a can be engaged and, so to speak, the position of the braking device can be fixed. The extendable piston device 2a and the engagement device 2b together form the locking device 2. The pressure chamber 1a is connected to the valve device 4, which, as already mentioned, has two inlets.Furthermore, a switching device 5 is provided on the valve device 4, which can switch the valve device 4 between the two inputs. One input is connected to the control device 6 for the service brake pressure, another input is connected to the control device 7 for the parking brake pressure. The control device 6 for the service brake pressure and the control device 7 for the parking brake pressure are also connected to a pressure vessel 3. Thus, through the valve device 4, the pressure chamber 1a of the brake cylinder can be connected either only to the control device 6 for the service brake pressure or to the control device 7 for the parking brake pressure.

[0031] Fig. 3 shows a detailed view of the extendable piston device 2a. The locking section 2a1 is movable and is pressed toward the engagement device 2b (not shown here) by a locking spring 2a2. This allows the locking section 2a1 to engage the engagement device 2b (not shown here) and thus fix the position of the braking device. Furthermore, a control pressure inlet 2a3 is provided. This allows the inlet of control pressure from the control device 7 for the parking brake pressure. A sufficiently high control pressure can overcome the spring force of the locking spring 2a2, and thus the fixation of the position of the braking device can be released.

[0032] The present invention is not limited to the above-mentioned embodiments.

[0033] The braking device can be a brake block in a block brake, but also a brake lining in a brake caliper for a disc brake.

[0034] A locking device can also be designed differently, for example, with the aid of a magnet or other components. Furthermore, the valve device 4 is not limited to a piston valve; a circuit with a double check valve is also possible. In this case, a switching device is not required; a switching mechanism may be necessary.

[0035] LIST OF REFERENCE SYMBOLS

[0036] B braking system

[0037] 1 brake cylinder

[0038] 1a pressure chamber

[0039] 1 b spring

[0040] 1c piston crown

[0041] 2 locking device

[0042] 2a extendable piston device

[0043] 2a1 Locking section

[0044] 2a2 Locking spring

[0045] 2a3 Control pressure inlet

[0046] 2b Intervention device

[0047] 3 pressure vessels

[0048] 4 Valve device

[0049] 5 Switching device

[0050] 6 Control device for the service brake pressure

[0051] 7 Parking brake pressure control device

[0052] 8 Braking device

[0053] 9 Connecting device

[0054] R wheel

Claims

PATENT CLAIMS 1 . Braking system (B) for a rail vehicle, comprising: a brake cylinder (1 ) with which a braking device (8) is operatively connected, wherein the braking device (8) is adapted to brake a wheel (R) of a rail vehicle, wherein the brake cylinder has a pressure chamber (1 a); a regulating device (6) for a service brake pressure; a control device (7) for a parking brake pressure; a valve device (4) which is adapted to connect either the regulating device (6) for a service brake pressure or the control device (7) for a parking brake pressure to the pressure chamber (1 a) of the brake cylinder (1 );a locking device (2) which is adapted to fix the position of the braking device (8) against release in a locked state and has no influence on the position of the braking device (8) in a released state, wherein the parking brake pressure is independent of the service brake pressure regulated by the control device (6) for a service brake pressure; 2. Braking system (B) for a rail vehicle according to claim 1, wherein the locking device (2) can be inserted by a spring (2a2) and can be released pneumatically, preferably by the control device (7) for a parking brake pressure.

3. Braking system (B) for a rail vehicle according to claim 2, wherein the parking brake pressure control device (7) is adapted to control a parking brake pressure and a release pressure for the locking device (2).

4. Braking system (B) for a rail vehicle according to one of the preceding claims, wherein the locking device (2) is integrated in the brake cylinder (1).

5. Braking system (B) for a rail vehicle according to one of the preceding claims, wherein the locking device (2) comprises an extendable device (2a) and an engagement device (2b), wherein the extendable device (2a) is adapted, in the locked state, to engage with the engagement device (2b).

6. Braking system (B) for a rail vehicle according to claim 5, wherein the brake cylinder (1) has a piston head (1c) and the piston head (1c) is connected to the braking device (8) via a connecting device (9), and the engagement device (2b) is preferably provided on the connecting device (9).

7. Braking system (B) for a rail vehicle according to one of the preceding claims, wherein the valve device (4) is a piston valve, and wherein the valve device (4) preferably has a switching device (5).

8. A method for engaging a parking brake of a rail vehicle with a braking system (B) according to one of claims 1 to 7, comprising the following steps: a) switching the valve device (4) so ​​that the pressure chamber (1a) of the brake cylinder (1) is connected to the control device (7) for the parking brake pressure; b) actuating the locking device (2) to fix the position of the braking device (8).

9. Method according to claim 8, further comprising the following step: c) venting the pressure chamber (1a) of the brake cylinder (1).

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