DE102012009425B3 - Pneumatic brake device for rail vehicle, has valve structure comprising conical, concave or convex shaped middle portion that is protruded perpendicular to fluid conducting pipe - Google Patents

Abstract

The pneumatic braking device has a main air pipe (1) that is indirectly coupled with a control valve (3) of a pneumatic braking cylinder (4), via a fluid-conducting pipe (2). A pneumatic actuator (6) is arranged for regulating pressure and flow control of fluid in fluid-conducting pipe. A valve structure (7) is arranged partially in a valve chamber (8) that is fluidly connected to fluid-conducting pipe such that a conical, concave or convex shaped middle portion (9) of valve structure is protruded perpendicular to fluid conducting pipe.

Description

FIELD OF THE INVENTION

The present invention relates to a pneumatic brake device, for trains having indirect brake, comprising a train passing through the main air line, the main air line is indirectly connected via a fluid-carrying line with at least one control valve for filling and venting at least one pneumatic brake cylinder, wherein between the at least one Control valve and the at least one pneumatic brake cylinder, at least one air reservoir for storing and providing a brake pressure for the at least one pneumatic brake cylinder is arranged.

The field of application of the present invention extends to rail vehicles, in particular to long train assemblies comprising a pneumatic braking device.

BACKGROUND OF THE INVENTION

Pneumatic braking devices for rail vehicles generally have a compressor provided on the drive unit, which feeds a main air line passing through the entire train via a driver brake valve. About the driver's brake valve is lowered to initiate a braking operation, the pressure in the main air line and increased to release the brake. The brake system of each car contains at least one control valve connected to the main air line, which controls the filling and venting of the corresponding brake cylinder as a function of a pressure change in the main air line. The compressed air required to fill the brake cylinders is taken from supply air tanks on each wagon. In the case of undesirable separation of the draw or damage to the main air line, braking is automatically initiated as a result of the lowering of the main line pressure.

In long train assemblies with a variety of wagons, among other things caused by pipe friction and cross-sectional change at coupling points line resistance caused in the main air line, to a long Auffüllzeit the air reservoir. While at the beginning of the dissolution process, the amount of compressed air flowing into the air reservoir at the front pulling part from the main air line is relatively large, a comparatively smaller quantity of compressed air is available at the end of the train. Therefore, the cars on the front part of the train faster and faster to reduce the braking force than the rear part. A later start of dissolution on the rear tension part can lead to dynamic reactions within the entire train, an extension of the train and thus high tensile forces on the couplings, especially on long trains. To reduce these forces, a timely release of all brakes throughout the train should be achieved. For this purpose, the pressure increase of the main air line must be controlled quickly by the entire train.

From the well-known prior art it is apparent that one approach for timely release of all brakes throughout the train is to treat the filling of the air reservoir with respect to the pressure increase of the main air line subordinate. Thus, less air is diverted to the air reservoir on each car, the available compressed air is used to fill the main air line. However, the filling of the air reservoirs may not be slowed or delayed as desired, since the criterion of inexhaustibility must be respected. The inexhaustibility criterion states that sufficient air pressure must be present in the air reservoirs at all times in order to be able to ensure a functioning braking operation. Since the air flowing from the air reservoir tanks in the individual cars to the brake cylinders air flowing when releasing no longer flows back into the air reservoir tank, but vented to the outside, the air reservoir loses at each braking to compressed air, which must be provided by the main air line again.

From the DE 27 02 855 B1 a pneumatic brake device for rail vehicles is known, which has a control valve with a brake cylinder associated with the three-pressure valve. To optimize the filling of the air reservoir with compressed air when releasing and charging the braking device of this control valve includes an additional filling valve, as for example from DE 26 45 575 B1 is known. This filling valve is designed as a special three-pressure valve with a shut-off valve arranged between the main air line and the air reservoir. This shut-off valve is loaded in the closing direction by a spring, a first piston acted upon by the brake cylinder pressure against atmospheric pressure, and a second piston acted upon by the air reservoir pressure against a constant reference pressure. When the brake is released, this filling valve, under the influence of the control chamber, air reservoir and brake cylinder pressures, controls the refilling of the air reservoir in proportion to the pressure drop in the brake cylinder. Up to a certain pressure, the air reservoir is filled from the main air line via the open shut-off valve. After reaching the specific pressure value closes the shut-off valve and the further filling of the air reservoir is throttled through a nozzle. This will cause the slow-moving Process of final pressure increase in the main air line until the release pressure is not further delayed by air suction into the air reservoir. In the entire main air line, the pressure values are compensated quickly, which makes the full solution faster. However, this filling valve requires a complex construction of the control valve.

From the EP 0 641 699 B1 is a pneumatic, preferably indirectly controlled, braking device for rail vehicles. This consists of at least one air reservoir, at least one pneumatic brake cylinder and at least one control valve for controlling the filling and venting of the brake cylinder. Furthermore, the braking device has a two-pressure valve connected to the main air line for generating a control pressure for the brake cylinder by means of a fixed charge throttle. Furthermore, the control valve has a pressure difference device assigned to the two-pressure valve, which maintains the pressure difference at the charge throttle at a predetermined value during each release operation. The air reservoir is connected to a connected to the charging throttle space of the pressure difference holding device. If the pressure difference at the charge throttle is kept constant, the volume flow through the charge throttle is also constant. Thus, a constant speed of pressure rise in the control chamber and in the air reservoir is achieved with repeated release operations of the brake independently of the main line pressure. However, the braking device requires a large number of components to solve the problem.

Furthermore, goes from the DE 36 34 653 A1 a braking device for rail vehicles, especially for long and fast trains out. The braking device has a device which is arranged or activated in the train within the rear half of the train, preferably at about ¾ of the train length. The device taps at each start of braking, preferably shortly after the onset of their neighboring operation or Ansprungbeschleuniger locally for a certain period of time or a certain amount of compressed air from the main air line. By to be connected as a separate device to the main air line or, in structural combination with the control valves only at the specific train body to be turned on an accelerated braking of the rear Zugteiles results, so that overall longer trains with higher driving speed at setting the control valves on faster brake pressure development times than before can be driven.

DISCLOSURE OF THE INVENTION

It is therefore the object of the present invention to provide a braking device for rail vehicles, which allows pressure and flow control with few components, which is to be ensured by the flow control a shortening of the release time of the brake system of the entire train and, consequently, a uniform and rapid filling of air reservoir.

The object is achieved on the basis of a braking device according to the preamble of claim 1 in conjunction with its characterizing features. Advantageous developments of the invention will become apparent from the following dependent claims.

According to the invention, a controllable, pneumatic actuator for pressure regulation and volume flow control is arranged on the fluid-carrying line connected indirectly to the air reservoir. The actuator comprises a valve body partially disposed in a valve space, a conical, concave or convex shaped central portion indirectly disposed with the air reservoir fluid carrying conduit, the central portion of the valve body extending perpendicularly into the fluid conducting conduit. The valve body is partially arranged in a valve chamber, wherein the valve chamber is fluidly connected to a fluid-carrying line.

About the central portion of the valve body, the feeling of the air reservoir is changeable and thus adaptable to the currently prevailing pressure. The effective cross-section of the fluid-carrying line is variable by the projecting into the fluid-carrying line central portion of the valve body, since the central portion has a non-constant contour. Depending on the position of the central portion of the valve body in the fluid-carrying line, the effective cross section of the fluid-carrying line is reduced or increased, thereby controlling the pressure and the volume flow.

According to a measure which further improves the invention, it is proposed that one end of the valve body has a piston, wherein the piston is arranged between the valve space and a zero space fluidly separated by the piston. Furthermore, it is in particular proposed that the piston has radially on an outer circumference a groove for receiving a sealing element. It is particularly important to seal the zero space and the valve space thoroughly against each other to prevent fluid exchange. Sealing elements that perform this task are preferably O-rings or dynamic seals. Instead of a groove, another fixation of the sealing element is conceivable. For example, the sealing element may be glued, pressed or screwed.

The invention includes the technical teaching that the piston is axially movable by acting on its end faces mechanical and / or pneumatic forces. The pressure building up in the valve space, which is due to an increase in the pressure in the fluid-carrying line, acts on the end face of the piston and displaces the piston axially. The preferably conically shaped contour of the central portion of the valve body moves together with the piston and reduces the effective cross-sectional area of the fluid-carrying conduit.

The invention includes the technical teaching that axially on the end face of the piston, a spring element is arranged in the zero space, wherein the spring element comes with an opposite end on the end face of an adjusting device arranged in zero space axially to the plant. The spring element can be compressed or stretched over the adjusting device, so that the force acting on the piston increases or decreases. Thus, the adjustment allows the force acting on the piston force to be set in the zero space such that a cross-section reducing pressure in the valve chamber is preferably 4 bar. As long as the pressure is less than 4 bar, the spring force is greater than the pressure in the valve chamber and the effective cross section of the fluid-carrying line thus maximum. Exceeding the pressure of 4 bar in the valve chamber displaces the piston axially and thereby also the central portion of the valve, wherein the effective cross-section of the fluid-carrying line decreases.

According to a first embodiment, preferably an air connection to the zero space is fluidly connected to ensure an atmospheric pressure in zero space. The air connection with which the zero space is fluidically connected preferably leads to the atmosphere and serves for aeration and venting of the zero space. As a result, the emergence of an overpressure in the zero space is prevented with an axial piston displacement.

According to a second embodiment, a control air connection is preferably arranged on the fluid-carrying line downstream of the actuator, wherein compressed air can be discharged from the fluid-carrying line into the zero space via the control air connection. The supply of compressed air into the zero space increases the force acting on the piston in the zero space and leads to a superposition of the pressure in the zero space with the spring force. Thus, the effective cross section of the fluid carrying conduit is dynamically adaptable.

The control characteristic of the volume flow thus takes place with the aid of the specific contour of the projecting into the fluid-carrying line middle section of the valve body, the choice of piston surfaces and restoring forces and the arrangement of the control air connection to the fluid-carrying line.

BRIEF DESCRIPTION OF THE DRAWINGS

Further, measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. Show it:

1 a schematic representation of a pneumatic brake device with an actuator disposed on a fluid-carrying line actuator,

2 a schematic sectional view of the actuator 1 , and

3 a schematic sectional view of the actuator according to another embodiment.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

1 shows a section of a pneumatic braking device of a train. In a continuous main air line 1 a defined operating pressure is maintained when the brake is released. Between the main air line 1 and a brake cylinder 4 is a control valve 3 with an air reservoir 5 arranged. The air reservoir 5 is from the main air line 1 via the control valve 3 filled. When braking, the pressure in the main air line 1 lowered. About the control valve 3 becomes a connection between the main air line according to the pressure differences 1 , the air reservoir 5 and the brake cylinder 4 manufactured and pressure in the brake cylinder 4 built up. To release the brake 18 becomes the pressure in the main air line 1 raised to the normal operating pressure. This will cause the brake cylinder 4 via the control valve 3 vented and the air reservoir 5 refilled. On a fluid-carrying line 2 is a controllable, pneumatic actuator 6 arranged for pressure and flow control.

2 shows in detail that on the fluid-carrying line 2 arranged actuator 6 in a first embodiment. The actuator 6 has a housing 19 in which a valve body 7 is arranged. The valve body 7 is in a valve room 8th axially movable, with a conical middle section 9 of the valve body 7 partially in the fluid-carrying line 2 protrudes. At a tapered end of the middle section 9 of the valve body 7 is a piston 10 arranged, which has a radial groove 12 in which a sealing element 13 is arranged. The piston 10 seals the valve chamber 8th from a null space above it 11 fluid technically. In the null space 11 is at an upper portion of the null space 11 an adjusting device 15 arranged between an end face of the piston 10 and an end face of the adjusting device 15 a spring element 14 is arranged. About a rotation of the adjustment 15 can the adjustment 15 be moved axially to compress or stretch the spring element, causing the on the piston 10 acting force increases or decreases. At the height of the spring element 14 is in the case 19 of the actuator 6 an air connection 16 trained, which is the null space 11 connects with the atmosphere and thus for a ventilation of the null space 11 provides. With an axial movement of the piston 10 against the spring force of the spring element 14 the volume of zero space decreases 11 , To an overpressure in zero space 11 to prevent and consequent additional force on the piston 10 Exclude, the zero space is through the air connection 16 vented. An axial movement of the piston 10 goes with an axial movement of the piston 10 connected middle section 9 of the valve body 7 accompanied and leads to a reduction of the effective cross-section of the fluid-carrying line 2 , Thus, a pressure and flow control, whereby the air reservoir 5 be quickly and evenly filled and beyond a timely release of all brakes 18 can be guaranteed.

3 shows an alternative embodiment of the on the fluid-carrying line 2 arranged actuator 6 , In this embodiment, in addition to a fluid at the leading line 2 downstream of the actuator 6 arranged control air connection 17 the compressed air from the fluid-carrying line 2 into the null space 11 dissipated. The feeding of compressed air into the zero space 11 increases the on the piston 10 acting force in zero space 11 and leads to a superposition of the pressure in zero space 11 with the on the piston 10 acting spring force of the spring element 14 , Due to the dependent on the effective cross-section of the fluid-carrying line pressure and flow, the discharged fluid amount depends on the control air connection 17 from. Thus, the effective cross section of the fluid carrying conduit is dynamically adjustable with increasing or decreasing pressure.

The invention is not limited to the preferred embodiments described above. On the contrary, modifications are conceivable which are included in the scope of protection of the following claims. For example, it is also possible to use the adjusting device 15 structurally to change, so that a compression or extension of the spring element is caused by electrical or magnetic components. Furthermore, the on the piston 10 acting force is a superposition of a variety of individual forces.

In addition, it should be noted that "encompassing" does not exclude other elements or steps, and "a" or "an" does not exclude a multitude. It should also be appreciated that features or steps described with reference to any of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limiting.

LIST OF REFERENCE NUMBERS

1

Main air line

2

fluid-carrying line

3

control valve

4

brake cylinder

5

Air reservoir

6

actuator

7

valve body

8th

valve chamber

9

middle section

10

piston

11

null space

12

groove

13

sealing element

14

spring element

15

adjustment

16

air connection

17

Usually air connection

18

brake

19

casing

Claims (7)

Pneumatic brake device, for train with indirect brake, comprising a train passing through the main air line ( 1 ), whereby the main air line ( 1 ) indirectly via a fluid-carrying line ( 2 ) with at least one control valve ( 3 ) for filling and venting at least one pneumatic brake cylinder ( 4 ), wherein between the at least one control valve ( 3 ) and the at least one pneumatic brake cylinder ( 4 ), at least one air reservoir ( 5 ) for storing and providing a brake pressure for the at least one pneumatic brake cylinder ( 4 ) is arranged, characterized in that at the indirectly with the air reservoir ( 5 ) connected fluid-carrying line ( 2 ) a controllable, pneumatic actuator ( 6 ) is arranged for pressure control and flow control, which a valve body ( 7 ) partially in a valve space ( 8th ), wherein the valve space ( 8th ) fluidically with the fluid-carrying line ( 2 ), and a middle section ( 9 ) of the valve body ( 7 ) perpendicular in the fluid-carrying line ( 2 ), which is conical, concave or convex. Braking device according to claim 1, characterized in that one end of the valve body ( 7 ) a piston ( 10 ), wherein the piston ( 10 ) between the valve space ( 8th ) and one through the piston ( 10 ) fluidly separated zero space ( 11 ) is arranged. Braking device according to claim 2, characterized in that the piston ( 10 ) is axially movable by acting on its end faces mechanical and / or pneumatic forces. Braking device according to claim 2, characterized in that the piston ( 10 ) radially on an outer circumference of a groove ( 12 ) for receiving a sealing element ( 13 ) having. Braking device according to claim 2, characterized in that axially on the end face of the piston ( 10 ) a spring element ( 14 ) in null space ( 11 ) is arranged, wherein the spring element ( 14 ) with an opposite end on the face of a in zero space ( 11 ) arranged adjusting device ( 15 ) comes to rest axially. Braking device according to claim 2, characterized in that an air connection ( 16 ) with the null space ( 11 ) is fluidly connected to an atmospheric pressure in null space ( 11 ) to ensure. Braking device according to claim 2, characterized in that on the fluid-carrying line ( 2 ) downstream of the actuator ( 6 ) a control air connection ( 17 ), wherein via the control air connection ( 17 ) Compressed air from the fluid-carrying line ( 2 ) into the null space ( 11 ) is dissipatable.

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