AT516356A1 - Method and actuating device for deicing a rail vehicle - Google Patents

Abstract

The invention relates to a method for deicing brake actuators (1) of a rail vehicle, wherein the brake actuators (1) can be moved from a rest position (2) in which the brake actuators (1) are opened into a braking position in which a closing force ( FS) is exerted on the brake actuators (1). The de-icing of the brake actuators (1), even during operation, is achieved by moving the brake actuators (1) from the rest position (2) to a de-icing position in which an opening force (FO) counteracting the closing force (FS) the brake actuators (1) is exerted to release icing.

Description

description

Method and operating device for deicing a rail vehicle5

Technical area

The invention relates to a method for deicing 10 brake actuators of a rail vehicle, wherein the

Brake actuators from a rest position, in which the brake actuators are opened, can be moved to a braking position, in which a closing force is applied to the brake actuators, and a 15 actuating device for performing the method.

Brake actuators generate a frictional force against a rotatable, braked component of a brake. Brake actuators may be, for example, brake calipers, calipers, brake pads, or brake shoes used in friction brakes such as disc brakes.

State of the art25

Rail vehicles are usually equipped with several braking systems, of which the friction brake is classified as relevant for safety. Such a friction brake converts the kinetic energy and the difference in potential energy via friction partners into heat. Here, brake actuators such as brake calipers or brake blocks are pressed against a counterpart, for example a brake disk, thereby causing the rail vehicle to brake or come to a standstill.35

In winter operation in particular, there is a risk that the brake actuators will freeze or freeze, because the development of heat during actuation of the brake causes ice or ice to melt.

Snow which has deposited on the elements during the journey. Once the heat energy has been released to the environment, the formed melt water freezes due to the speed of movement of the rail vehicle and the low outside temperatures, forming an "ice sheet". around the brake actuators.

This freezing endangers the safe operation of the rail vehicle, since the friction brakes can be 10 worst if they can not move and therefore there is an increased risk of accidents.

It is known that rail vehicles are defrosted after being used outdoors in thawing halls to perform a de-icing. In the process, icing is removed on the entire vehicle and especially in the area of the brakes, so that at the beginning of the next operation it can be guaranteed that no more icing exists. 20 For this purpose steam tractors often become fast

De-icing used. This, however, favors the penetration of water into the brake cylinder, which can lead to corrosion of the brake cylinder. In addition, the high pressure of the steam straightener can also lead to damage in the area of the bellows and the seals.

Also disadvantageous is the fact that de-icing can take place only during down time and is not possible during operation30.

OBJECT OF THE INVENTION It is therefore an object of the present invention to provide a method and a device for vehicles, in particular rail vehicles, which does not have the drawbacks of the prior art, and a vehicle

De-ice the brake actuators even during active operation allows. In particular, existing brake systems should be cost-effective and easy to retrofit.

Presentation of the invention

This object is achieved by a method having the features of patent claim 1. Advantageous embodiments of the invention are defined in the respective dependent claims.

It is according to the invention provided that the brake actuators are moved from the rest position to a de-icing position in which a closing force counteracting the closing force is exerted on the brake actuators in order to release icing.

The braking position refers to a position in which the brake actuators contact their counterpart, for example a brake disk, and a force proportional to the closing force is exerted on the counterpart. A rest position is understood to mean a position in which the brake actuators do not contact the counterpart and also that no closing force is exerted on them.

The opening force and movement to the de-icing position can remove icing of the brake actuators resulting from the melting of snow and ice due to heat build-up during a braking operation and subsequent freezing of the melt water. By the force proportional to the opening force, indicative of such an "ice sheet". is exercised, this is blown up, splintered or broken off. The movement into the defrosting position can also be done during running operation, ie while driving, of a rail vehicle, so that permanent icing is prevented and thus the functioning of the braking system is given at all times.

In order to provide a simple actuator mechanism for the required forces, an embodiment provides that the opening force or closing force exerted on the brake actuators is generated via a piston guided in a brake cylinder. The cylinder / piston principle is a proven principle of rail vehicle technology which is reliable, easy to manufacture and assemble.

According to a further embodiment of the invention, the piston divides the brake cylinder into two chambers and the opening force or closing force of the piston is achieved by a change of the pressure in at least one of the chambers. An embodiment of the brake cylinder as a double-acting cylinder in which the piston can be pressurized in both side-respects in both formed chambers is advantageous because movement of the piston in both directions can be brought about by a pressure change in the respective chamber. The pressure change leads to a movement of the piston or to the construction of an opening or closing force. The pressure change can be either continuous or stepwise. Existing brake systems with single-acting cylinders can easily be converted to double-acting cylinders.

An alternative embodiment of the invention provides that - in the rest position prevails a first pressure level in one of the chambers, - in the braking position prevails a second pressure level in the same chamber, which is lower than the first pressure level and - in the defrosting position prevails a third pressure level in the same chamber, which is higher than the first

Pressure level. In particular, in passive braking systems, such as spring-applied brakes, the braking force is generated by a spring element disposed in one of the two chambers. In the rest position that chamber is loaded without spring element with the first pressure level, so that the spring element is biased and the brake actuators are opened. To move the brake actuators from the rest position to the brake position, the pressure level is lowered to the second pressure level so that the spring element relaxes and exerts the closing force on the piston. To move the brake actuators from the rest position to the

To move defrosting position, the pressure level is increased to the third pressure level, so that the spring element is biased and acts by the difference of the first and third levels of pressure, the opening force on the piston. So also for a passive braking system in a simple manner, a de-icing during operation can be performed.

In a further embodiment variant, the medium used for pressure build-up is liquid or gaseous, preferably compressed air or hydraulic oil. This makes it possible to use pneumatic or hydraulic systems to build up the required pressure. Liquid media have the advantage that they are usually incompressible, but because of their viscosity, they can only be used in a certain temperature range. Gaseous media are zwarkompressibel, but for example, compressed air can be produced at any time nachnach and there are no relevant for the process, temperature limits.

A particularly preferred embodiment provides that the movement of the brake actuators from the rest position to the de-icing position proceeds in the opposite direction as the movement into the braking position. Thus, for example, a mechanical malfunction is precluded that results in movement to the braking position, although movement to the defrost position is desired. Such a

However, a malfunction would be conceivable if the braking position and the de-icing position were in the same direction of movement. Thus, in the defrost position, the brake actuators are even farther from their counterpart, such as a brake disc, than in the rest position.

In a further particularly preferred embodiment it is provided that the brake actuators are moved by 1 to 8 mm, preferably 2 to 6 mm, from the rest position to the de-icing position. The movement of the brake actuators outwards, ie away from the counterpart, for example the brake disk, splits or breaks off the icing between the brake actuator and the counterparts, without significant heat energy being generated, which could again lead to feeds.

According to another particularly preferred

Embodiment variant, the opening force is between 20 and 50 kN, preferably between 30 and 40 kN. According to experience, this force is sufficient to be used in practice

Dissolve icing.

The object stated in the introduction is also achieved by an actuating device for carrying out a method according to the invention with which the brake actuators can be moved by means of a closing force from a rest position into a braking position. The stated object is achieved by the fact that the brake actuators are movable to a de-icing position by means of an opening force.

An actuator serves to apply the required closing or opening force. In this case, the actuator is connectable to the brake actuators, wherein also other elements between the actuator and the brake actuators can be arranged. Connectable refers in this context to the power flow, which must be forwarded to the brake actuators themselves.

In a preferred embodiment of the actuating device, the distance between the rest position and the defrosting position of the brake actuators is between 1 and 8 mm, preferably 2 and 6 mm. This creates a motion that ruptures and splinters the icing, with the chipped ice falling down from the gap between the brake actuator and the counterpart (brake disc).

A further preferred embodiment of the actuating device provides that it comprises a brake cylinder and a piston guided therein, wherein the piston is movable from a rest position to a braking position and connected to the brake actuators. Here, the brake position of the piston is understood to mean the position that the piston occupies when the brake actuators are in the braking position, as closed. Since, due to the mechanical connection along the force flow, the piston and the brake actuators are connected, a unique braking position of the piston is attributable to the braking position of the brake actuators. Analogous considerations apply to both the rest position and the defrost position.

In order to enable defrosting also for a passive braking system, for example a spring-loaded brake, an alternative embodiment of the invention provides that the piston divides the brake cylinder into two chambers and in the first chamber a spring element and in the second chamber a first pressure supply line is arranged, wherein the spring element in the De-icing position has a higher bias voltage than in the rest position. It is of course genausodenkbar that the first and second chamber are reversed or. also in the spring element having the chamber a second pressure supply line is provided.

According to a further preferred embodiment of the actuating device, the piston divides the brake cylinder into two chambers and a corresponding pressure supply line is arranged in each chamber. The division into two chambers is due to the cylinder - piston principle, since the piston must at least seal the two chambers against each other to allow pressure buildup. The volume of the two chambers is not static, but changes with the position of the piston in the brake cylinder. However, since both chambers have their own and separately controllable pressure feed line, it is possible to obtain a double-acting cylinder in which a pressure build-up in each of the two chambers is possible and thus the piston can exert both a closing force and an opening force counteracting the opening force on the brake actuators. In alternative embodiments, in at least one of the chambers, a spring element may be arranged which exerts a bias on the piston in at least one position.

In a further preferred embodiment of the actuating device, at least one valve is provided, which is connected on the one hand to the pressure supply lines and, on the other hand, can be connected to a pressure source. By means of one or more valves, a pressure source, for example a pressure circuit or a pressure vessel connected to a compressor, can be used in a simple manner to pressurize both pressure supply lines.

A particularly preferred embodiment provides that via only one valve, depending on the desired position of the piston, the pressure supply lines are releasable and closable. The position of the valve thus allows only one pressure supply line to be pressurized while the other remains closed. As a result, a separate control of the pressure lines is achieved. In an alternative embodiment, there is a valve position in which neither of the two pressure supply lines is pressurized when they are both closed and a valve position in which both pressure supply lines are open. The desired position of the piston refers to the resting, braking or de-icing position.

A further particularly preferred embodiment provides that in the braking position of the piston, the first pressure supply line is released and the second is closed to build up pressure in the first chamber and in the de-icing position the second pressure supply line is released and the first one is closed to build up pressure in the second chamber. The built-up pressure in one of the chambers results in movement of the piston, increasing the volume of the chamber involved, or establishing a closing or opening force. The nature of the installation of the brake cylinder and the connection with the brake actuators determines which chamber pressure has to be built up in order to reach the desired direction of movement of the piston.

According to a further particularly preferred embodiment, the valve is electromagnetically controllable and the valve is preferably a 4/2-way valve. The electromagnetic drive makes it possible to effect a change in the valve position, for example via a central on-board electronic system, so that, for example, the rail vehicle operator can cause the movement of the brake actuators to the de-icing position from the driver's cab. A 4/2-way valve, ie a valve which has four connections, including a vent connection and allows two different valve positions, is particularly well suited to supply pressure to a double-acting cylinder. Depending on the design variant, however, other valves are also conceivable which have more connections or allow valve positions.

Brief description of the figures

To further explain the invention, reference is made in the following part of the description to the figures, from which further advantageous embodiments, details and further developments of the invention are to be taken. The figures are to be considered as exemplary and, while indicating the inventive character, they are by no means exhaustive or even exhaustive. Show it:

Fig. La an actuator of an active

Brake system, wherein the brake actuator is in the rest position

FIG. 1b shows an actuating device of an active braking system in the braking position FIG. 1c, an actuator of an active brake system in defrost position FIG. 2a an actuator of a passive

Brake system, wherein the brake actuator is in the rest position

Fig. 2b shows an actuator of a passive braking system in the braking position Fig. Fig. 2c shows an actuating device of a passive braking system in the defrosting position

Embodiment of the invention

In the figures, for the sake of clarity, only one brake actuator 1 is depicted, which in this exemplary embodiment is designed as a brake caliper 1. Also, the illustration of a counterpart, for example, a brake disk, which must forcibly have a friction surface and is attached to an axle of the rail vehicle, has been omitted for the same reason. It goes without saying, however, that the second brake caliper of a pair of brake calipers can be actuated analogously to the brake caliper 1 described in the following, or else brake calipers 1 of a different design operate on the same principle.

The brake caliper 1 shown in the figures is shown only schematically and consists of a friction surface 15, a molded part, which is mounted via a pivot joint, anda lever, which is engaged by an actuator. A variety of different configurations of the brake caliper 1 are possible, in particular a cross-over at the swivel, but the embodiments have no influence on the operation according to the invention.

Figures la, b, c refer to a so-called active braking system of a rail vehicle. In this case, a brake cylinder 6 is provided in which a piston 5 is guided. The piston 5 divides the brake cylinder 6 into a first chamber 7 and a second chamber 8 and is connected to the brake caliper 1. In this case, the piston 5 is so educated that it seals the two chambers 7,8 against each other and the chambers 7,8, depending on the position of the piston 5, reduce or enlarge. Via a valve 12, which is designed here as a 4/2-way valve, the pressure build-up in the chambers 7, 8 is regulated. For this purpose, the valve 12 is connected on the one hand to a pressure source 13, for example a high-pressure line or a high-pressure system or a compressor, and on the output side to a first pressure feed line 9 and a second pressure feed line 11. The pressure feed lines 9, 11 serve to build up pressure in one of the chambers 7, 8, for which reason the first pressure feed line 9 is connected to the first chamber 7 and the second pressure feed line 11 is connected to the second chamber 8, wherein the medium used in the pressure circuit is either air, in a pneumatic pressure system, or hydraulic oil, in a hydraulic pressure system. The valve 12 is actuated electromagnetically via a control device.

Fig. La shows an active braking system described above, in which the brake caliper 1 with its friction surface 15 is in the rest position 2. In this case, none of the chambers 7,8 is pressurized and a spring element 14 arranged in the second chamber 8, in this case a return spring, has no pretension - the brake caliper 1 or its friction surface 15 is not in engagement with the counterpart, for example the friction surface of a brake disk.

If the first pressure supply line 9 is now released via the valve 12, the pressure in the first chamber 7 increases and the piston 5 moves linearly in the brake cylinder 6 to the left, whereby the friction surface 15 of the brake calliper 1 moves to the right into a braking position 3 in which a closing force occurs Is applied to the brake caliper 1, as shown in Fig. Lb. In this case, the spring element 14 is biased in the second chamber 8. The closing force Fs is amplified via the lever law, then introduced via the friction surface 15 of the brake caliper 1 into the counterpart, for example the friction surface of a brake disc, whereby the kinetic energy as well as the change of the potential energy of the rail vehicle is converted into frictional heat. If the pressure supply via the first pressure supply line 9 is set, the bias of the spring element 14 provides the necessary restoring force to move the piston 5 and the brake caliper 1 and their friction surface 15 back to the rest position 2.

Due to the development of heat and subsequent cooling, icing of the brake calipers 1 can now occur, as mentioned at the beginning, so that in certain circumstances the entire mechanics of the brake caliper 1 may be adversely affected.

In order to minimize this safety-relevant risk, it is now possible to release the second pressure feed line 11 via the valve 12, so that pressure builds up in the second chamber 8 and the piston 5 moves in the opposite direction - in this case to the right - whereby an opening force F0 on the brake clamp 1 As a result, the friction surface 15 of the brake calliper 1, preferably between 2 and 6 mm, is removed from its counterpart, for example the friction surface of a brake disc (thus reaches the de-icing position 4, which here for the friction surface 15 to the left of the rest position 2) and exerts a force proportional to the opening force F0 on the icing, whereby the icing splinters or breaks off without generating appreciable heat energy. This ensures that the brake caliper 1 is fully operational at any time.

Alternative embodiment of the invention

Figures 2a, b, c show an alternative embodiment in which a passive braking system, such as a spring-loaded brake, is used instead of an active braking system. The basic construction of the brake systems is the same as described above, in the following only the relevant differences are discussed:

In contrast to the active brake system, in a passive brake system in the rest position 2, the second chamber 8 is pressurized so that a spring element 14 arranged in the first chamber 7 has a bias, as can be seen in FIG. 2a. In the present embodiment, the brake cylinder 6 is designed as a single-acting cylinder, so that only the second chamber 8 has a pressure feed line 9. The pressure feed line 9 is connected to a pressure source 13, wherein the arrangement of valves is conceivable, e.g. a valve 12 as shown in FIG. la.

When the pressure in the second chamber 8 is reduced, the piston 5 is moved by means of the spring force of the spring element 14 into the braking position 3 in which it exerts a closing force Fs on the brake caliper 1. This position is shown in Fig. 2b.

In order to generate an opening force F0 and to move the piston 5 or the brake caliper 1 into the defrosting position 4 (FIG. 2c), it is necessary for the pressure source 13 to be able to provide a second higher pressure level for the second chamber 8 than in the rest position 2 ,

The advantage of a passive braking system is that a possible pressure loss in the pressure source 13 leads to an automatic movement into the braking position 3. As a result, a safe braking can be guaranteed at any time. In contrast, in an active braking system, a drop in the pressure in the pressure source 13 or in the pressure source 13 results in the pressure

Pressure supply lines 9,11 or the valve 12 to a failure of the brakes.

LIST OF REFERENCES: 1 brake actuator (brake caliper) 2 rest position 3 braking position 4 defrosting position 5 piston 6 brake cylinder 7 first chamber 8 second chamber 9 first pressure supply 10 actuation device 11 second pressure supply 12 valve 13 pressure source 14 spring element 15 friction surface of the brake actuator 1

Claims (17)

A method for deicing brake actuators (1) of a rail vehicle, wherein the brake actuators (1) can be moved from a rest position (2) in which the brake actuators (1) are opened to a braking position (3) in which a closing force (Fs ) is applied to the brake actuators (1), characterized in that the brake actuators (1) are moved from the rest position (2) to a defrost position (4) in which an opening force (Fs) opposing the closing force (Fs) is applied to the brake actuators (1). is exercised to solve a dispute. A method for deicing brake actuators (1) of a rail vehicle according to claim 1, characterized in that the opening force (F0) or closing force (Fs) exerted on the brake actuators (1) is achieved by a piston (5) operating in a brake cylinder (6) is performed is generated. A method for deicing brake actuators (1) of a rail vehicle according to claim 2, characterized in that the piston (5) divides the brake cylinder (6) into two chambers (7, 8) and the opening force (F0) and closing force (Fs) of the piston (5) is achieved by changing the pressure in at least one of the chambers (7, 8). A method for deicing brake actuators (1) of a rail vehicle according to claim 3, characterized in that - in the rest position (2) a first pressure level predominates in one of the chambers (7,8), - in the braking position (3) a second pressure level in the same chamber (7,8), which is lower than the first pressure level, and - in the defrosting position (4), there is a third pressure level in the same chamber (7,8), which is higher than the first pressure level. Method for defrosting brake actuators (1) of a rail vehicle according to claim 3 or 4, characterized in that the medium used for pressurizing is liquid or gaseous, preferably compressed air or hydraulic oil. Method for defrosting brake actuators (1) of a rail vehicle according to one of Claims 1 to 5, characterized in that the movement of the brake actuators (1) from the rest position (2) to the defrost position (4) is in the opposite direction as the movement to the braking position (3). Method for deicing brake actuators (1) of a rail vehicle according to one of Claims 1 to 6, characterized in that the brake actuators (1) move from rest position (2) to de-icing position (4) by 1 to 8 mm, preferably 2 to 6 mm. be moved. 8. A method for deicing brake actuators (1) of a rail vehicle according to one of claims 1 to 7, characterized in that the opening force (F0) is between 20 and 50 kN, preferably between 30 and 40 kN. Actuation device (10) for a method for deicing brake actuators (1) of a rail vehicle according to any one of claims 1 to 8, by which the brake actuators (1) are movable from a rest position (2) to a braking position (3) by a closing force (Fs) characterized in that the brake actuators (1) are movable to a defrosting position (4) by means of an opening force (Fs) counteracting the closing force (Fs). Actuating device (10) according to claim 9, characterized in that the distance between the rest position (2) and the defrosting position (4) of the brake actuators (1) is between 1 and 8 mm, preferably 2 and 6 mm. Actuating device (10) according to claim 9 or 10, characterized in that it comprises a brake cylinder (6) and a piston (5) guided therein, the piston (5) being movable from a rest position (2) to a braking position (3) connected to the brake actuators (1). 12. Actuator (10) according to claim 11, characterized in that the piston (5) divides the brake cylinder (6) into two chambers (7,8) and in the first chamber (7) a spring element (14) and in the second chamber (8) a first pressure supply line (9) is arranged, wherein the spring element (14) in the defrosting position (4) has a higher bias voltage than in the rest position (2). 13. Actuator (10) according to claim 11, characterized in that the piston (5) divides the brake cylinder (6) into two chambers (7, 8) and that in each chamber (7, 8) a corresponding pressure supply line (9, 11) is provided. is arranged. 14. Actuating device (10) according to claim 13, characterized in that at least one valve (12) is provided, which on the one hand connected to the pressure supply lines (9,11) and on the other hand with a pressure source (13) is connectable. Actuating device (10) according to claim 14, characterized in that via a valve (12), depending on the desired position of the piston (5), the pressure supply lines (9, 11) are releasable and closable. Actuator (10) according to claim 15, characterized in that in the braking position (3) of the piston the first pressure feed (9) is released and the second (11) is closed to build up pressure in the first chamber (7) and in the de-icing position (4) the second pressure supply line (11) is released and the first (9) is closed to build up pressure in the second chamber (8). 17. Actuating device (10) according to any one of claims 14 to 16, characterized in that the valve (12) is electromagnetically controllable and that the valve (12) is preferably a 4/2-way valve.