Railway braking system for railway vehicles, with brakes having at least one shoe, and railway vehicles equipped with such a system

Abstract

The invention relates to a railway braking system (1) comprising a cylinder (2) configured to act on a wheel (7) via a brake shoe (3) and such that, in parking brake configuration, the braking force applied to the wheel is directly proportional to the braking force applied in service or emergency brake configuration; a force transmission rod (9) mechanically attached to the brake cylinder and the brake shoe; an elastic device (20) configured to be stressed by the cylinder and acting directly on the brake shoe; and an interface mechanism (4) interposed between the cylinder and the elastic device. The system is configured to allow the brake shoe to move via the rod in a horizontal and / or vertical direction and also via the interface mechanism at least vertically in translation and / or pivoting, to follow the movement of the wheel. (Figure 1)

Description

Description Title of the invention: Railway braking system for railway vehicles, with brakes having at least one shoe, and railway vehicles equipped with such a system Technical field of the invention

[0001] = The invention relates to the field of braking of lorry vehicles. relates more specifically to a railway braking system with brakes at least a clog.

[0002] = The invention also relates to a railway vehicle with brakes having at least one shoe including such a braking system. State of the art

[0003] — Patent application EP 2 826 684 describes a railway braking system in which the braking force applied in parking brake configuration is directly depending on the braking force applied in service brake configuration or emergency brake. Indeed, the system includes a brake piston that is immobilized. in service or emergency braking position by means of a brake locking device parking. This means the brake piston can be immobilized in any which position, which position is linked to the stroke that this piston has traveled and this The travel depends on the force applied during the service or emergency braking phase.

[0004] — In document EP 2 826 684, this refers to a brake system with linings and braking linkage equipped with levers, for example, which are substantially deformable. In other words, the term immobilize means that the force applied by the piston of braking on the brake linkage in the brake working configuration Parking does not decrease, or hardly at all. There may be some loss due to the reversal. of the brake piston, in particular the slight displacement of the piston relative to the locking device, at the moment when the service brake pressure chamber is drained. This loss is controlled and is defined as a very slight decrease in the force applied to the brake linkage levers.

[0005] In document EP 2 826 684, the system is notably freed from the springs of the known braking systems described for example in patent application EP 2 154,040 and which allow the parking brake force to be applied to the steering linkage of braking via the piston of the service brake cylinder.

[0006] There are also railway vehicles known as having brakes with at least one shoe, or with minus one sole, these two terms being used interchangeably in this memorandum In contrast, these are generally equipped with brake cylinder systems. service and / or parking, comprising a body, a piston movable relative to the body under the effect of a pressurized fluid, the movement of this piston actuates a shoe holder, or sole holder, on which at least the shoe, or sole is mechanically attached, and resulting in a braking action such as clamping the shoe, or sole, on a wheel of the vehicle. Such a braking system is mounted on the railway vehicle to be in contact with one or more wheels. In particular, it can be mechanically attached to a bogie, or to an axle fixed to the bogie, or to another device such as a drive motor or gearbox also mounted on the bogie. In addition, such a braking system, for shoe brakes, is equipped with transmission links mechanically attached on one side to the shoe holder and on the other side to the body of the braking system. It is well known that railway vehicles are equipped with suspension systems which inherently generate movements between the wheels and the rest of the vehicle, including the braking systems. Therefore, due to wheel movements, the system's attachment to the vehicle support, the transmission links, and also wear on both the wheel and the brake shoes, the latter can be in different positions relative to the wheel when a braking force is applied. Furthermore, such a braking system, for shoe brakes, does not have a linkage with, for example, deformable levers, so the actual braking force applied to the wheel may not be the same depending on the position of the shoes relative to the wheel. This is even more true in the case of a parking brake application such as that described in EP 2 826 684, particularly when the service brake pressure chamber is emptied. In other words, the loss during recoil may not be negligible. Description of the invention The invention relates to a railway braking system with brakes having at least one shoe, in which the braking force applied in parking brake configuration is directly a function of the braking force applied in service or emergency brake configuration, and which is simple, convenient and economical while being particularly reliable in the application of the braking force, both in service or emergency brake configuration and in parking brake configuration. The invention thus relates, in a first aspect, to a railway braking system for a railway vehicle with brakes having at least one shoe, comprising a shoe holder configured to carry said at least one shoe, a brake cylinder configured to act on at least one wheel of the railway vehicle via the brake shoe carrier, and at least one force transmission link as- mechanically subjected on one side to the brake cylinder and on the other side to the shoe carrier, with the braking system which is configured to allow the shoe carrier, via at least one force transmission link, to move in a horizontal direction and / or in a vertical direction to follow the position of the wheel to be braked of the railway vehicle;characterized in that the brake cylinder is configured so that, in parking brake configuration, a braking force applied to the vehicle wheel is directly a function of a braking force applied in service or emergency brake configuration, and in that the railway braking system comprises an elastic device configured to be stressed by the brake cylinder and acting directly on the brake shoe, as well as an interface mechanism interposed between the brake cylinder and the elastic device and configured to also allow movement of the brake shoe, at least vertically in translation and / or pivoting, to follow the movement of the wheel to be braked of the railway vehicle. The railway braking system according to the invention thus offers the possibility of using a device which is free in particular from the springs of known braking systems described for example in patent application EP 2 154 040, on vehicles equipped with shoe brakes, while being particularly reliable and precise in the application of the braking force. In other words, thanks to the braking system according to the invention, the braking force applied by the shoes of the system on the wheel of the railway vehicle is normally substantially homogeneous regardless of the position of the shoe holder relative to the wheel and more generally regardless of the position of the wheel relative to the system. Preferred, simple, convenient and economical characteristics of the railway braking system according to the invention are presented below. The brake cylinder comprises a body and an actuating rod movable relative to the body and which is mechanically secured by a free end to the interface mechanism. The interface mechanism includes a locking / unlocking device in the position of the brake cylinder actuating rod. The interface mechanism comprises a main component from which one or more pivot pieces protrude laterally and from which a sliding link protrudes frontally towards the shoe holder. The interface mechanism includes one or more connecting riders mounted movable in rotation around the pivot part(s), and one or more sliding parts mounted movable in horizontal and / or vertical translation between the connecting rider(s) and the elastic device. The connecting bracket(s) allow the hoof holder to pivot by report to the brake cylinder. The sliding piece(s) allow for the vertical and / or horizontal axial movement of the shoe holder relative to the brake cylinder. The sliding piece(s) have a C-shape, having a large arm configured to bear against the elastic device, and two small arms extending on either side of the large arm and forming a space for receiving the connecting rider(s). The interface mechanism includes at least one device forming an axial sliding stop for the sliding part. The elastic device and the interface mechanism are housed in a chamber provided in the shoe holder, opposite a mounting face of one or more shoes. The hoof holder is equipped with one or more chamber closure covers. The elastic device comprises a plurality of elastic blades arranged vertically against each other. The brake cylinder includes an actuation mechanism powered pneumatically and / or electrically. The invention also relates, in a second aspect, to a railway vehicle with shoe brakes, comprising at least one railway braking system as described above and configured to act on at least one wheel of the vehicle. Brief description of the figures We will now continue the exposition of the invention by describing examples of implementation, given below by way of illustration and not limitation, with reference to the attached drawings. Figure 1 schematically and kinematically illustrates a railway braking system according to the invention acting on a wheel of a railway vehicle with shoe brakes comprising this system. Fig. 2 is a side-view perspective of an example of the railway braking system shown in Fig. 1. [Fig.3] is a partial perspective view of the railway braking system of [Fig.2]. Figure 4 illustrates in exploded perspective a shoe holder and an interface mechanism of the railway braking system visible in Figure 3. Fig. 5 is a view similar to that of Fig. 4, from a different viewing angle. Fig. 6 is a similar view to Fig. 3 but cut away so as to partially visualize in particular the interface mechanism housed in the hoof holder. Figure 7 is a partial cross-sectional view of the visible railway braking system. on [Fig.3], in a first braking configuration. [Fig.8] is similar to that of [Fig.7], in a second braking configuration. [Fig.9] is a partial cross-sectional view of the railway braking system visible in [Fig.3], in a position where the shoe holder is pivoted downwards. [Fig.10] is similar to that of [Fig.9], in a configuration where the shoe holder is pivoted upwards. Fig. 11 is a partial cross-sectional view of the railway braking system visible in Fig. 2, in an initial wear position of the shoe holder. The [Fig.12] is similar to that of the [Fig.11], in a second wear position of the shoe holder. Detailed description Figures 1 and 2 schematically illustrate, in side perspective, a railway braking system 1 comprising a railway brake cylinder 2 coupled to a shoe holder 3 via an interface mechanism 4. The railway braking system | is configured here to be mounted on a railway vehicle known as a shoe brake. The shoe holder 3 is designed to receive, on a mounting face 5, one or more brake shoes 6 configured to come into contact with a wheel 7 of the railway vehicle for braking and / or immobilizing the latter. The brake cylinder 2 here includes an actuation mechanism powered pneumatically and / or electrically and configured so that in parking brake configuration, a braking force applied to the wheel 7 is directly a function of a braking force applied in service brake or emergency brake configuration. The brake cylinder 2 is mechanically secured to a bogie, or to an axle fixed to the bogie, or to another device such as a drive motor or gearbox also mounted on the bogie, belonging to the railway vehicle, as illustrated by reference 8. The railway braking system 1 here includes force transmission rods 9 mechanically secured by a first end to the brake cylinder 2 and by a second end, opposite its first end, to the shoe holder 3. The brake cylinder 2 here comprises a body 10, a braking mechanism (not shown) movable inside the body 10 along a first axial direction and an actuating rod 12, or push rod, movable relative to the body 10 along a second axial direction represented by an arrow 11, orthogonal to the first axial direction. The braking mechanism is configured on the one hand to act and driven in de- placement of the actuating rod 12. The braking mechanism can be formed, for example, by a piston or, more generally, by a mechanical element. The actuating rod 12 extends outward from the body 10 and is mechanically secured by a free end to the interface mechanism 4. In the illustrated example, the interface mechanism 4 of the railway braking system | includes a locking / unlocking device 14 in the position of the actuating rod 12 of the brake cylinder 2. The brake cylinder 2 is provided with attachment arms 13 extending outward from the body 10 and to which the force transmission links 9 are mechanically attached. Figure 2 shows in particular that the railway braking system 1 is configured to allow the shoe carrier 3, via the force transmission links 9, to move in a horizontal direction over a distance D1 and / or in a vertical direction over a distance D2 to follow the position of the wheel to be braked of the railway vehicle. This movement is made possible by the mounting of the force transmission links 9 which can substantially pivot at their second end around the attachment arms 13. We will now describe, with reference to figures 3 to 6, the hoof holder 3 and the interface mechanism 4. The shoe holder 3 comprises a main body 15 in which is provided a main recess forming here a chamber 16 intended to accommodate the interface mechanism 4 as well as an elastic device 20 of the railway braking system 1. Such an elastic device 20 is configured here to be stressed by the brake cylinder 2, in particular its actuating rod 12 and via the interface mechanism 4, and to act directly on the shoe holder 3. The elastic device 20 and the interface mechanism 4 are therefore housed in the chamber 16 provided in the shoe holder 3, opposite its mounting face 5 for one or more shoes, The shoe holder 3 is here provided with several closing covers 17, 18 mechanically fastened laterally and frontally on the main body 15 of the shoe holder 3, by means of fixing screws 21, and a seal 19 mounted on the front cover around the free end of the actuating rod 12. In particular, in the illustrated example, the chamber 16 of the hoof holder 3 is provided here with a central cavity 22, two lateral cavities 23 delimited from the central cavity 22 by lateral walls 24 and a recess 25 made at the bottom of the central cavity 22. The main body 15 of the hoof holder 3 has a front attachment face 26 of which protrude guide pins 27 for mounting the front cover 18, and side attachment faces 28 for mounting the side covers 17. Notches 29 are provided on the front face of the attachment 26 for the reception of a stop screw 30 ([Fig.6]). The elastic device 20 here comprises two sets of a plurality of elastic blades 31 arranged vertically against each other, each set of elastic blades 31 being housed in a respective lateral cavity 23. The elastic blades 31 in the illustrated example have a roughly rectangular shape with a dome-shaped boss on one long side. Other shapes of elastic blades are possible, for example rectangular without a boss, or with a boss on each long side, oval, square, etc. In addition, elastic blades can be made of metal, for example from steel, or of elastomer, or of composite materials. The interface mechanism 4 includes a main member 32 here in the form of a ball joint, having an internal space 33 in which the locking / unlocking mechanism 14 is housed and where the control rod 12 is secured by a connecting piece 34. The interface mechanism 4 includes pivot parts 35, formed here for example by round protrusions, which protrude laterally from the main member 32 and a sliding link 36, formed here for example by a protuberance, which protrudes frontally from the main member 32 towards the shoe holder 3. The main organ 32 is intended to be housed in the main cavity 22 of the chamber 16, with the sliding link 36 housed in the recess 25 provided at the bottom of the central cavity 22. The interface mechanism 4 includes a release tab 37 mechanically secured to the locking / unlocking mechanism 14 and extending downwards in projection from the main member 32. It should be noted that a through hole (not visible) is provided in the main body 15 of the shoe holder 3, and opens into the main cavity 22 for the passage of the unlocking tab 37 so that the latter is accessible from the outside of the main body 15 of the shoe holder 3. The interface mechanism 4 includes connecting riders 38 mounted movable in rotation around the pivot parts 35 and are intended to ensure the pivoting of the brake carrier 3 relative to the brake cylinder 2, due to the movement of the force transmission rods. The connecting riders 38 here have, in section, an L shape, with an opening 39 provided in a large arm 40 of the L for the at least partial reception of a respective pivot piece 35, and a small arm 41 of the L which comes in the immediate vicinity of a respective side of the sliding connection 36. The interface mechanism 4 includes sliding parts 42 which facilitate the vertical and / or horizontal axial movement of the shoe holder 3 relative to the brake cylinder 2, due to the movement of the force transmission links. The sliding parts 42 are mounted to move in horizontal and / or vertical translation between the connecting brackets 38 and the sets of elastic blades 31 of the elastic device 20. The slide pieces 42 each have in the illustrated example a C shape, having a large arm 43 configured to bear against a respective set of elastic blades 31 of the elastic device 20, and two small arms 44 extending on either side of the large arm 43 and forming a receiving space for a respective connecting jumper 38. An additional notch 45 is provided on each small arm 44 to form, with a respective notch 29 and stop screw 30, a device forming an axial sliding stop for the respective slide piece 42. The slide pieces 42, together with the connecting riders 38, are received in the lateral cavities 23, with the large arms 43 of the slide pieces 42 which are located opposite the respective sets of elastic blades 31 of the elastic device 20. Thus, the interface mechanism 4 is interposed between the brake cylinder 2, in particular its actuating rod 12, and the elastic device 20. The interface mechanism 4 is further configured to also allow movement of the shoe holder 3, at least vertically in translation and / or pivoting, to follow the movement of the wheel to be braked of the railway vehicle. Figures 7 and 8 show the railway braking system 1 in different braking configurations, respectively in a first braking configuration where the actuating rod 12 has been moved forward so as to act on the shoe holder 3; and in a second braking configuration where the actuating rod 12 has been moved backward, for example due to recoil play. In the first configuration, the actuating rod 12 acts on the main member 32 of the interface mechanism 4 which, through its connecting riders 38, acts on the slide pieces 42, with the large arm 43 of each slide piece 42 bearing against a respective set of elastic blades 31 of the elastic device 20. The elastic blades 31 are thus in a compressed state, bearing against the bottom of the respective lateral cavities 23, and the force applied on the shoe holder 3 is optimal. In the second configuration, the actuating rod 12 has retracted slightly, and the force applied to the interface mechanism 4 could decrease. The elastic blades 31 then return to a stable position in which they are not, or are less, compressed than in the first configuration. The elastic blades 31 then partially move away, particularly in the center, from the bottom of the lateral cavities 23. respective. Thus, the elastic properties of the elastic blades 31 of the elastic device 20 make it possible to limit the force potentially lost in recoil. Between the first and second configurations, we see that the sliding parts 42 have been moved, together with the connecting riders 38 and therefore the main body 32 via the pivot parts 35 to come into axial contact substantially against an internal wall of the front closing cover 18. Figures 9 and 10 show how the shoe holder 3 can pivot, up or down, around the actuating rod 12 to follow the movement of the railway vehicle wheel. In particular, it is the linking riders 38 which pivot around the pivot parts 35 projecting from the main body 32 of the interface mechanism 4, without preventing the large arms 43 of the slide parts 42 from bearing against the respective sets of elastic blades 31 of the elastic device 20. In [Fig.9], the hoof holder 3 is pivoted by an angle Al so that the hoof holder is directed upwards, while in [Fig.10], the hoof holder 3 is pivoted by an angle A2 so that the hoof holder is directed downwards. Here, the elastic blades 31 are shown in a not fully compressed state but, of course, they could be in a fully compressed state as in [Fig.8]. Figures 11 and 12 show the shoe holder 3 respectively in a first wear position and in a second wear position. In other words, figures 11 and 12 show the vertical axial displacement of the sliding parts 42 relative to the connecting riders 38, due to the displacement of the shoe carrier 3 driven by the force transmission links 9. In particular, on [Fig.11], the sliding piece 42 is moved upwards by a distance V1, with its large arm 43 sliding vertically along the small arm 41 of the connecting rider 38. In this first wear position, the connecting rider 38 is also in contact with the small arm 44 of the sliding piece 42 which is downwards and therefore at a distance from the small arm 44 of the sliding piece 42 which is upwards. In [Fig.12], the sliding piece 42 is moved downwards by a distance V2, with its large arm 43 sliding vertically along the small arm 41 of the connecting rider 38. In this second wear position, the connecting rider 38 is also in contact with the small arm 44 of the sliding piece 42 which is upwards and therefore at a distance from the small arm 44 of the sliding piece 42 which is downwards. It should be noted that the locking tab can be mechanically secured to a locking finger mounted on the connecting piece between the actuating rod and the component main locking / unlocking mechanism. Such a system can be used not only to lock the actuating rod in position, for example to limit its recoil movement, but can also be used alternatively or in addition to tightening the system and in particular to put the shoe holder in its nominal position, for example when the shoes have been changed. It should be noted that the brake cylinder body and / or the connecting rods and / or the shoe holder can be made of metal or can be made from aluminium and / or magnesium, and / or from carbon, carbon fibres or polymer. The elastic device may include one or more elastic blades and / or one or more spring washers, and / or one or more elastomer blocks and / or components made from composite materials. More generally, the invention is not limited to the examples described and shown.

Claims

Demands

1. DC railway braking system for a railway vehicle with brakes less one shoe (6), comprising a shoe holder (3) configured to carry said at least one shoe, a brake cylinder (2) configured to act on at least one wheel (7) of the railway vehicle via the shoe holder, and at least one force transmission link (9) as- mechanically subjected on the one hand to the brake cylinder and on the other hand to the shoe holder, with the railway braking system (1) which is configured to allow the hoof holder, via at least one connecting rod for transmitting force, to move in a horizontal direction or along a vertical direction to follow the position of the brake wheel of the railway vehicle; characterized in that the cylinder The brake is configured so that in parking brake mode, a braking force applied to the wheel of the railway vehicle is di- directly as a function of a braking force applied in a configuration of service or emergency brake, and in that the braking system fer- roviary includes an elastic device (20) configured to be stressed by the brake cylinder and acting directly on the carrier shoe, as well as an interface mechanism (4) interposed between the cylinder brake and elastic device configured to also allow a movement of the hoof holder, at least vertically in translation and / or pivoting, to follow the movement of the wheel to be braked railway vehicle.

2. Railway braking system according to claim 1, characterized in that the brake cylinder (2) comprises a body (10) and a rod actuation (12) mobile relative to the body and which is subjected to me- mechanically by a free end to the interface mechanism (4).

3. Railway braking system according to any one of claims 1 and 2, ca- characterized in that the interface mechanism (4) includes a device locking / unlocking (14) in the actuating rod position (12) of the brake cylinder (2).

4. Railway braking system according to any one of claims 1 to 3, ca- characterized in that the interface mechanism (4) comprises an organ main (32) from which one or more pivot pieces protrude laterally (35) and from which protrudes frontally towards the hoof holder (3) a sliding joint (36).

5. Railway braking system according to claim 4, characterized in that the interface mechanism (4) includes one or more jumpers connecting (38) mounted movably rotating around the part(s) pivot (35), and one or more sliding parts (42) mounted movable in horizontal and / or vertical translation between the connecting jumper(s) and the elastic device (20).

6. Railway braking system according to claim 5, characterized in that the sliding part(s) (42) have a C-shaped form, having a large branch (43) configured to come against the elastic device (20), and two small branches (44) extending from and on the other side of the large branch and forming a reception space for the or liaison riders (38).

7. Railway braking system according to any one of claims 5 and 6, ca- characterized in that the interface mechanism (4) includes at least one device forming axial sliding stop for the sliding part (42).

8. Railway braking system according to any one of the claims indications 1 to 7, characterized in that the elastic device (20) and the interface mechanism {4) are housed in a chamber (16) provided in the shoe holder (3), opposite a mounting face (5) of a or several hooves (6).

9. Railway braking system according to claim 8, characterized in that the shoe holder (3) is equipped with one or more covers of closure (17, 18) of room (16).

10. Railway braking system according to any one of the claims indications 1 to 9, characterized in that the elastic device (20) comprises a plurality of elastic blades (31) arranged vertically against each other.

11. | Railway braking system according to any one of the claims indications 1 to 10, characterized in that the brake cylinder (2) comprises a pneumatically powered actuation mechanism (4) and / or electrically.

12. Railway vehicle with shoe brakes, comprising a braking system railway (1) according to any one of claims 1 to 11 and which is configured to act on at least one wheel (7) of the vehicle.