Device for controlling compressed-air-controlled brakes on rail vehicles

The invention relates to a device for controlling compressed air-controlled brakes on rail vehicles, in particular indirectly controlled brakes, with a controllable pressure control valve for pressure adjustment of the compressed air in a main air line or brake cylinder line.

There are already known driver brake valves for the indirect brake, whose essential component is a 5 mechanically controllable pressure control valve. In this case, the adjusting spring is compressed by moving a handle via a screw, whereby the pressure in the main air line in a normal operating range is continuously variable (usually approx. 3 - 5 bar). This normal operating range includes those pressures in the main air line, which allow braking and release of the brakes, so the usual ferry operation. Deviating pressures such as seven bar for fast filling of the main air line and the designated auxiliary air tank for loading the brake cylinder or approx. zero bar for rapid braking can not be adjusted with a known mechanical pressure control valve in practice, because on the one hand such a large entire control range would make accurate control in the normal operating range (between 3 and 5 bar) and on the other hand, a time-dependent automatic reset from the filling out only would be possible with great effort.

In order to make time-dependent pressure increases (filling) while using such mechanical pressure control valves, therefore, numerous additional pneumatic components such as valves, tanks, nozzles and relay valves are necessary, which are generally mounted on the driver's brake valve and form a unit with this. Although such known brake controls meet all the requirements prescribed in the railway industry, but are particularly expensive in terms of space and piping. If a number of driver's cabs are provided in a locomotive, several such complex valve combinations must be arranged, and at the same time it must be ensured by mechanical or pneumatic means that only one driver-brake valve arrangement can be in operation at a time.

In radio-controlled locomotives mechanically controllable pressure control valves can no longer be used. It was therefore for time-dependent pulse control by solenoid valves, in which over the Öflhungsdauer certain solenoid valves of a set of solenoid valves, the pressure in the main air line is changeable

However, such pulse controls also have a costly piping, as necessarily a relay valve must be followed in order to make the behavior of the brake of the volume of the main air line and the train length independently.

From EP-A2-152 958 a braking device for rail vehicles is known, which has an electrically controllable pressure control valve. The known pressure control valve is a relay valve in which the main line pressure is controlled according to a pneumatic pilot pressure (A pressure). This A-pressure is controlled electronically, whereby the actual value input of the electronics via a pressure / voltage converter receives a signal proportional to the A-pressure. This has the disadvantage that

Pressure deviations (such as sticking or binding of valves), which are caused by the relay valve in the translation of the A-pressure in the main line pressure, are not detected by the control electronics. In the known braking device is thought to realize the function of rapid braking (pressure reduction to zero) regardless of the control electronics and the pressure control valve.

EP-Al-14 369 relates to a device in which the pressure control by at least one

Solenoid valve takes place, which can take stable continuously adjustable intermediate positions between the opening and closing positions (proportional solenoid). Thus, this document describes only a special type of valve design and the electronic control, but not the arrangement in the brake system.

DE-OS 28 40 262 describes an electronically controlled braking system, wherein the pressure control via

Solenoid valves takes place. In order to achieve sufficiently short braking and release times, these solenoid valves must have large cross-sections, on the other hand, an accurate and sensitive pressure control difficult. In addition, this results in a complicated system with many devices. A compact design, as it is the object of the invention, among other things, can not be achieved.

The CH-PS 546 659 describes a pressure control valve with a torque motor as an actuator, which can be used in electrical paths to compensate for the effect of an electric resistance brake. This valve is not suitable for controlling the main air line pressure of an indirect brake.

The object of the invention is to provide a device for controlling compressed air-controlled brakes for rail vehicles, in particular indirectly controlled brakes, the fast and sensitive adjustment of a desired braking effect (regardless of the volume of the main air line or the

In addition, the device should take up little space and allow a simple piping.

This is achieved according to the invention in that the actual value input of the pressure control valve is connected to the main air line or the brake cylinder line and that the control range of the pressure control valve comprises all provided for operating the brake in the main air line and brake cylinder line pressure values

With the aid of the electrically controllable pressure control valve as a driver brake valve of an indirectly controlled brake of rail vehicles, on the one hand, the pressure values ​​required in the normal operating range (about 3-5 bar) in the main air line can be adjusted quickly and sensitively. On the other hand, but also

-2AT392238B pressure values ​​outside this normal operating range, such as about 0 bar for rapid braking or, for example, 7 bar for filling via the same pressure regulating valve. This beyond the normal operating range extending control range does not affect the accuracy of the pressure control in the normal operating range when using a suitable electrically controlled pressure control valve. Furthermore, the electrically controlled pressure control valve according to the invention detects the actual main air line pressure as an actual value. Thus, there is a complete control of the main air line pressure, whereby a more accurate and safer adjustment of the main air line pressure is possible, as in the known from EP-A2-152 958 device. In addition, the present invention built-pressure control valve over the known pressure control valve in the construction is simpler, in particular no A-pressure vessel is necessary.

In addition to savings in space requirements and in the piping (it needs in the locomotive practically only a single pneumatic control element, namely the electrically controllable pressure control valve to be present) combines the electrically controllable pressure control valve at the same time accurate and quick adjustability and the possibility of remote control. The inventive use of an electrically controllable pressure control valve allows a unified pneumatic braking equipment and thus a simplified storage, since in virtually all occurring in railway applications the same pressure control valve can graze used, the adaptation to the particular application only in the electrical or electronic equipment or their programming shows

The use of an electrically controllable pressure control valve whose control range comprises all provided in the brake cylinder line pressure values ​​for a directly controlled brake (as u. a. provided in locomotives) has over mechanically operated valves in addition to the small footprint and the Femsteuerbarkeit above all the advantage that a similar electrically controllable pressure control valve can be used as for an indirect brake. Since in the railway already side by side indirect and direct brakes exist, so that the braking equipment is further standardized and simplifies storage

Further details and advantages of the invention will be explained in more detail in the following description of the drawings with reference to embodiments

The figures show 1 a schematic brake system control of a locomotive with an embodiment of the inventive device for controlling a direct brake and with an embodiment of the inventive device for controlling an indirect brake, Fig. 2 a profile of the output signal of an electronic control unit for controlling the electrically controllable pressure valve for the indirect brake and 3 a profile of the output signal of another electronic control unit for controlling the electrically controllable pressure valve for the direct brake.

The central components of the brake system control shown in Fig. 1 are the two electrically controllable pressure control valves (1) (for the indirect brake) and (2) (for the direct brake), which serve the pressure value in the main air line (3) for the set indirect brake or in the brake cylinder line (4) for the direct brake.

First, the control of the indirectly controlled brake will be described. According to the invention, the control range of the electrically controllable pressure control valve (1) comprises all pressure values ​​intended for operating the brake in the main air line (3). The actual value input of the pressure control valve (1) is (in the embodiment shown via a later-described double check valve (10)) connected to the main air line (3). The main air line (3) leads in a known and therefore not shown way to the actual provided with Hilfsluftbehältem and control valves brake system, via which the actual brake cylinder are acted upon. Lowering the pressure in the main air line causes the brakes to close, increasing the pressure will release the brakes. In practice, these pressure values ​​are between approx. 5 bar (release) and approx. 3 bar (brakes). Outside this normal operating range (3-5 bar) in an indirect brake in general still higher pressures for rapid filling of the brake system (auxiliary air tank) and lower pressures for rapid braking on the main air line must be feasible. In contrast to previously known controls, where the functions filling and rapid braking "on separate pneumatic components, carried out in the illustrated embodiment of the device according to the invention also the realization of these functions filling and rapid braking via the electrically controllable pressure control valve (1), without the sensitivity and to affect the speed of the control in the normal operating range.

The electrical control of the pressure control valve (1) takes place in the simplest case (not shown) via a equipped with a control lever potentiometer, wherein optionally parallel to the potentiometer or parallel to a series resistor of the potentiometer, which limits the main air line pressure to 5 bar, a switch is arranged by closing this switch, the potentiometer or the series resistor for the function Fill are bridged, whereby the pressure relief is canceled and the main air line with the pressure of the air tank (5) is acted upon.

In the illustrated embodiment, the control of the electrically controlled pressure control valve (1) by two Bremssteuerschaltanordnungen (6) via a programmable control unit (7), whose output signal depending on the closing duration of the function release or braking assigned

-3AT392238B

Preferably, switch of the brake control switch assembly (s) increases substantially linearly within adjustable limits; falls. An adjustable maximum value of control current or voltage can limit the main air line pressure. The rising and falling speed of the main air line pressure is determined by the electronic ramp generator provided in the control unit in accordance with the regulations of the trajectories. By the brake control switch assemblies (6) or by a remote control, a sensitive and advantageously largely independent of the number and type of the attached cars largely independent braking or releasing the indirect brake can be achieved over the operating time. The output signal changes in the normal range, as shown in FIG. 2 is shown approximately in the middle. The pressure data in FIG. 2 refer to the pressure set by the pressure control valve (1) controlled analogously by the output signal shown.

Via an additional contact on the brake control switching arrangement or on the remote control for the function filling the ramp generator can be bridged and the main air line (3) with the pressure of the Luftbehalteis (5) via the pressure control valve (1) are acted upon, the output signal of the control unit 2 runs in the left area

The program of the electronic ramp generator contains jump points in the present exemplary embodiment (cf. FIG. 2), which ensure a function currently prescribed by the railways. When briefly activating the function Brakes (i. H. the associated switch of the brake control switching arrangement) causes a jump point at the beginning of the ramp, a rapid reduction of the main line pressure by 0.4 bar, which automatically in all cars the 1. Brake level is controlled. This advantageously ensures a simultaneous response of the brakes of all cars. When the release function is actuated, a jump point at the end of the ramp, as soon as a main air line pressure of 4.75 bar is reached, automatically raises it to 5 bar, whereby the brakes of all the wagons are desirably released simultaneously.

As shown in FIG. 2 stating the electronic control unit (7) according to a preferred feature of the invention is designed to that they fill after the function Fill, in which the pressure in the main air line is raised to a maximum value, as well as when you use the Match function, provides an output signal, which corresponds to a main air line pressure of max. 6 bar, and that the electronic control unit independently lowers this output signal to an output signal within a few minutes, which corresponds to approximately 5 bar main air line pressure (Fig. 2). The pressure reduction takes place so slowly that the control valves do not initiate braking in the car. This can be reduced by filling with tank pressure resulting overloads of the control valves in the car.

The pressure control valve (1) is equipped with a device for limiting the Nachspeiseleistung, which consists according to a preferred feature of the invention of an orifice (9) and a double check valve (10). At high air consumption, as z. B. occurs when the emergency brake valve (8) or an open emergency valve in a car, occurs through the orifice a quantity limit. If, in this case, the pressure transducer of the pressure regulating valve were connected directly to the main air line (3), then the pressure regulating valve (1) would fully open due to the low main air line pressure. By in Fig. 1 However, shown arrangement between the orifice (9) and pressure control valve (1) existing, higher pressure via the double check valve (10) is supplied to the pressure transducer, whereby the pressure control valve (1) does not open fully and the make-up is further limited. The resulting at the orifice (9) pressure drop leads to a reduction of the main air line pressure and thus for safe response of the brakes. Upon actuation of the function brakes on the brake control sound arrangement, the now higher pressure in the main air line is measured via the double check valve (10), and the orifice (9) thereby advantageously has no influence on the pressure control.

A similar electrically controlled pressure control valve (2) can also be used for the direct brake provided in the locomotive, at the pressure of the leading brake cylinder to the brake cylinder (11) brake cylinder line (4) directly determines the braking effect. Also in the direct brake, the control range of the pressure control valve (2) comprises all in the brake cylinder line (4) provided pressure values, wherein the maximum Bremszylindeidruck may be limited by the control current or the control voltage.

By one of the two brake control switch assemblies (12), the brake cylinder pressure (= pressure in the brake cylinder line (4)) via the electronic control unit (13) between zero and maximum can be set arbitrarily. This control unit (13) contains in the present embodiment, a Rampbildner, the the pressure regulating valve (2) supplied output signal (and thus the brake cylinder pressure) in response to the operating time of a brake switch or Release switch, which can also be remotely controlled, linearly lowers or lifts (cf. FIG. 3). A sensitive and advantageously by the volume of the brake cylinder largely independent braking or release is possible.

The pressure control valves (1) and (2) are designed so that when switching off or failure of the power supply line (3) or (4) is completed and thus the previously set pressure is obtained. Thus, a sealing performance test of the brake system can be made. In the case of the indirect brake, a possibly provided solenoid valve in closed-circuit mode or another emergency brake valve can obtain the function of the quick-brake function.

The pressure control valves (1) and (2) may include, for example, a proportional solenoid, a servomotor or two solenoid valves with pressure control loop. Conveniently, the pressure control valves

-4AT392238B can be controlled analogously and have a substantially linear relationship between the input signal and the regulated pressure value. The pressure control valves can also have integrated electronic circuits.