Movable point frog for a railway track and method for replacing such a movable point of a frog

Abstract

The invention relates to a movable point frog for a railway track, comprising: • a cradle comprising a main-track wing rail (4) and a turnout-track wing rail (5), each provided with at least one rail, • a movable point assembly, comprising a fixed heel forming a main track and a turnout track, and a movable point (1) arranged between the two wing rails, • an operating device configured to move the movable point between a main-track position, pressed against a main-track wing rail, in which it forms a continuous running surface between the wing rail and the main track of the fixed heel, and a turnout-track position, pressed against a turnout-track wing rail, in which it forms a continuous running surface between the turnout-track wing rail and the turnout track of the fixed heel, the movable point assembly comprising a point rail (2) extending to the movable point, and a counter-point rail assembled laterally to the point rail. At least one wing rail comprises a block (6, 7) fastened to the at least one rail on the side of the wing rail oriented toward the movable point, the top of the block being arranged lower than the top of the rail so that a wheel passing over the frog is borne by the rail and guided but not borne by the block.

Description

Moving-point frog for railway track and method for replacing such a moving-point frog in a crossing frog

[0001] The present invention relates to the field of railway infrastructure. It relates more particularly to a movable-point core made of assembled rails, for example for high-speed operation.

[0002] The movable-point hearts known for high-speed lines are generally composed of a one-piece cast manganese steel cradle, with welded antennas and hare's legs, on one side, and a movable point on the other.

[0003] Such a cast manganese steel cradle requires, on the one hand, the manufacture of a mold, which represents high costs and delays, and on the other hand, complex tri-metal welds for the connections to the rails that will extend this cradle; such welds are not only complex, but also have a high environmental impact.

[0004] There are movable point frogs with cradles made of assembled rails; document KR 2003 0062096 describes such a movable point frog with a straight track frog, a diverging track frog, a movable point, a point rail and a counter-point rail; however, the area of ​​passage from the frog to the movable point is then less resistant than a manganese steel; in addition, it is not possible to optimize the geometry of the running surface without weakening the frog rail, which is incompatible in particular with high-speed traffic.

[0005] The problem that the present invention aims to solve is to propose a solution for a moving-tip core that meets the quality criteria required, for example, for a high-speed railway track, but is simpler to manufacture.

[0006] One object of the present invention is to provide a moving-tip core with a lower environmental impact.

[0007] Another object of the present invention is to offer a moving-tip core with shorter manufacturing time and lower manufacturing cost.

[0008] Another object of the present invention is to provide a moving-tip core with reduced maintenance costs.

[0009] The present invention aims to address, at least in part, the aforementioned objectives by proposing a movable-point crossing frog for railway track, comprising: a cradle having a straight track frog and a diverging track frog, each equipped with at least one rail; a movable point assembly, comprising a fixed heel forming the straight track and the diverging track, and a movable point disposed between said two frogs; a control device configured to move the movable point between a straight track position, pressed against a straight track frog, in which it forms the continuity of the rolling motion, between said frog and the straight track of the fixed heel, and a diverging track position, pressed against a diverging track frog, in which it forms the continuity of the rolling motion, between said diverging track frog and the diverging track of the fixed heel.said moving point assembly comprising a point rail extending to the moving point, and a tailstock rail assembled laterally to said point rail,

[0010] This crossing frog is special in that at least one frog has a block, fixed to at least one rail on the side of the frog oriented towards the moving point, the top of the block being lower than the top of the rail so that a wheel passing over the frog is carried by the rail and guided but not supported by the block

[0011] Thanks to these arrangements, we obtain a crossing heart that can be manufactured largely from rails, avoiding the need to make a large molded part; in addition, thanks to the block, we can optimize the geometry without weakening the hare's foot; finally, the block can be easily replaced, which facilitates maintenance, the block being in an area of ​​high wear due to the rolling of passing trains.

[0012] According to other characteristics: the moving point may have at its front end a vertical extension away from the running surface, and said block may have a housing, said extension and housing being configured so that when the moving point is in its position pressed against said track brake, said housing constitutes a vertical stop for said extension and thus prevents the moving point from lifting; such an arrangement increases safety for the moving point and for the rolling stock during its passage, in particular in the case of the use of magnetic braking; said block may be made of a material having a hardness greater than that of said rail, preferably a hardness of at least 350 HB; the material may, for example, have a hardness between 350 and 370 HB, or even a hardness greater than 400–440 HB; such an arrangement allows for a longer service life of the wear part constituted by said block.and it is less expensive to achieve such hardness on a small part than on an entire cradle; the two track legs can each comprise a block as claimed, and the block of the straight track track leg is connected to the block of the diverging track leg, the two forming a single piece; such an arrangement allows for a reduction in the number of parts and improved part strength; the block and / or the moving point assembly can be configured so as to be removable on track, without requiring dismantling of the cradle; this arrangement allows for a significant reduction in maintenance costs; said block can be equipped with measuring sensors, in particular an accelerometer, or a positioning or displacement detector, which facilitates the manufacture of the cradle by concentrating the more complex arrangements related to the placement of sensors on a smaller, removable part.Modular; this arrangement also allows easy access to such sensors for installation or maintenance. The rail profile height can be the same for the running track rails and the rails of the two frogs, which facilitates connections, generally by welding, from the frog rails to the rails connecting the movable point frog to the turnout, and avoids forging the ends of the frogs or point / counterpoint. The rail profile is the same for the running track rails and the rails of the two frogs, which further facilitates these connections. The movable point can include a first rail forming the point and a second rail forming the counterpoint, and the rail profile height is the same for the running track rails and the rails forming the point and counterpoint. The movable point can include a first rail forming the point and a second rail forming the counterpoint.and the rail profiles are the same for the running track rails and the rails forming the point and counterpoint; the movable point may comprise a first rail forming the point, and a second rail forming the counterpoint; and the means for assembling the counterpoint to the point comprises a spacer configured to guarantee a sliding clearance between the point and the counterpoint, preferably a sliding clearance of a value between 0.05 and 4 mm, preferably between 0.2 and 0.4 mm; such an arrangement makes it possible to reduce the transverse inertia of the movable point and makes possible deformations without a heel joint for smaller deflection radii and shorter movable point frogs; the operating device may comprise at least one bistable elastic device, disposed between said movable point and said frog, and configured to exert an assistance in the movement of the movable point and a holding force in position,This is in the direction of the movement of the moving point towards its straight track position on the one hand, or towards its diverging track position on the other; such an arrangement reduces the number of motorized or linkage-operated approaches from a motor; in some cases, it even allows the linkage to be completely eliminated and the maneuver to be carried out by only one motor. The two hare's legs can each have a straight section of at least 20 cm, preferably at least one meter, in length, and the straight sections of the two hare's legs can be arranged opposite each other in the crossing frog so as to form a straight section, preferably encompassing the position of the end of the moving point; such an arrangement facilitates the installation of a moving point lock which mechanically holds the end of the moving point in place when the latter is not being moved.

[0013] The present invention also relates to a method for replacing a moving point of a crossing frog according to the invention with a new moving point, comprising the following steps: uncoupling of said operating device and said moving point; removal of at least one block; removal of stops and fixings of the rear end of the moving point; cutting of welds between the point on one side and the counter-point on the other with rails; removal of the moving point; installation of a new moving point

[0014] Thanks to these provisions, the maintenance of such a crossover core is greatly facilitated.

[0015] The present invention will be better understood upon reading the detailed description that follows, with reference to the accompanying figures in which:

[0016] This is a top view of a heart with a movable tip according to the invention.

[0017] This is a section according to AA of the hare's foot of the heart with a movable tip of the,

[0018] This is a section according to BB of the mobile tip of the heart to the mobile tip of the,

[0019] Laest is a CC-shaped cut of the heart with a movable tip,

[0020] This is a close-up view of the moving-tip core, in its first operating position.

[0021] This is a detailed view of the [detail], in a second operating position.

[0022] The present invention relates to a movable-tip core suitable for use, for example, in high-speed lines or in subway tracks.

[0023] As can be seen in figures 1 and 2, the movable-point core has a movable point 1, with a point 2 and a counter-point 3.

[0024] The movable-point heart has two hare's legs 4 and 5, one straight track hare's leg 4, and one diverging track hare's leg 5.

[0025] The point 2 extends to the front end of the movable point 1, and it provides support for a wheel as it leaves the hare's foot (4, 5). The tailstock 3 widens the movable point 1 towards the rear whenever it needs to be wider than a rail profile.

[0026] The words "front" and "rear" should be understood as follows: for a movable point 1, the front is the side where the movable point 1 forms a point, and the rear is the side where it is connected to two rails; in the case where the movable point frog 1 is inserted into a bifurcation, the front is the side of the switch, and the rear is the other side, on the side of the two separate tracks.

[0027] The movable point frog has at least one block 6, 7; generally it has two blocks 6, 7, one running track block 6, and one diverging track block 7.

[0028] The block 6, 7 is fixed to the hare's foot 4, 5 on the side where it guides a wheel of rolling stock for example by a bolted assembly; it is also the side of the hare's foot 4, 5 oriented towards the movable point 1.

[0029] The block 6, 7 widens the hare's leg 4, 5 as soon as it has to move away to make room for the movable point 1, and up to the effective position of the front end of the movable point 1.

[0030] The block then takes over the guidance of the wheel from the point where the hare's foot moves away, until the movable point 1 takes over the guidance.

[0031] The shape of the rail / wheel contact, along with the small gap required for the brake shoe, ensures that the wheel's load is provided by the brake shoe up to the tip of the movable point 1, and beyond, until the tip 2 of the movable point 1 begins to provide some of the load, and again until tip 2 provides all the wheel's load. Thus, the block never provides any load to the wheel; this allows for continuous load-bearing and a single transfer of load, directly from the brake shoe 4, 5 to the tip 2. The block therefore improves guidance without compromising ride comfort when passing over the movable point frog. This improved guidance prevents an increase in rolling stock sway, which would increase the risk of derailment at high speeds.

[0032] We also avoid the disadvantages of another solution to this problem: machining the mushroom of the hare's foot; in this solution, we ensure guidance, but we weaken the hare's foot, which is undesirable because it leads to an increase in stresses and therefore a reduction in service life.

[0033] The solution proposed by the invention, a block fixed to the frog, offers the advantage of a part that can be easily removed on track. This block can indeed be disassembled, and therefore replaced, without disassembling the frogs or the moving point; as this part wears more than other parts, this provides an advantage in the maintainability of the moving-point frog, and an improvement in its lifespan before partial or complete replacement of the moving-point frog.

[0034] Moreover, the block can be made of a stronger material than a rail profile; as it is a relatively small part, compared to the whole of a hare's leg, a stronger and more expensive material can be used, without significantly impacting the cost of the entire moving-tip core 1.

[0035] Furthermore, the proposed solution allows the block to have an optimized geometry, without the limitation imposed by the rail profile used.

[0036] In the case of asymmetrical wear of the moving-point core, for example in the case not of a bifurcation, but of a crossing, it is possible to replace only one of the two blocks 6, 7, the one which has unacceptable wear, while leaving the other in track for a longer time.

[0037] Also, when such a moving-tip core is damaged, only the deteriorated block will be replaced.

[0038] According to a particular embodiment of the invention, the straight track block 6 and the diverging track block 7 are part of a single piece, which can be disassembled by sliding it forward from the movable point frog after removing the bolts. This has the advantage of reducing the number of parts to be assembled and improving the stability of the block.

[0039] According to a preferred embodiment of the invention illustrated in Figure 1, the movable tip 1 has at its front end a vertical extension 8 positioned away from the running surface, and block 6, 7 has a housing 9. The extension 8 and housing 9 are configured so that when the movable tip 1 is in its position against the track lug 4, 5, the housing 9 acts as a vertical stop for the extension 8 and thus prevents the movable tip from lifting. In this way, the front end of the movable tip 1 is held securely during the passage of a train and is not at risk of lifting, particularly in the event of magnetic braking of the rolling stock. A chamfer may be provided on the lateral side of the extension 8 and / or the housing 9 to facilitate the insertion of the extension into the housing during the operation of the movable tip.

[0040] According to another preferred embodiment of the invention illustrated in the figure, the means for assembling the tailstock 3 to the point 2 comprises a spacer 10 configured to guarantee a sliding clearance between the point 2 and the tailstock 3.The opening provided in the point 2 and counterpoint 3 to allow the spacers and bolts to pass through is oblong, with a length in the direction of the rails greater than the height by several millimeters; thus the point 2 and the counterpoint 3 can slide relative to each other by several tenths of a millimeter, or even a few millimeters, for example up to 4 millimeters, which gives greater flexibility to the movable point 1, and makes it possible to deform the movable point 1 between its straight track position and its diverging track position for shorter movable point frogs than in the absence of this possibility of sliding, and while fixedly embedding the movable point 1 at its rear end.

[0041] The sliding clearance can have a value between 0.05 and 4 mm, preferably between 0.2 and 0.4 mm.

[0042] The spacers 10 have a length configured to encompass the thicknesses of the two webs of the center and tailstock, as well as the space between these two webs. Plates 11, also having an anti-rotation function by adapting to the bottom of the web, and which may be provided with two holes, are arranged on each external face of the web of the center and tailstock, so that a bolt 12 can tighten the two plates 11, which bear against the spacer 10, and not directly on the web of the center and tailstock.

[0043] The bearing force of the tailstock against the center is thus perfectly controlled and managed. This allows, when the moving center 1 is deformed for maneuvering, for longitudinal sliding between the center 2 and the tailstock 3. The moment of inertia that defines the rigidity of the moving center 1 is then closer to the moment of inertia of the center alone than to the moment of inertia of the center and tailstock assembled without sliding; the necessary deformation is thus possible even for relatively short moving centers, for smaller radii of deviation of a bifurcation, without a breather joint at the rear end of the tailstock 3 for example.

[0044] According to a preferred embodiment of the invention, adjustment shims 21 are arranged between the spacer 10 and one of the plates 11, and allow to maintain a controlled functional clearance between center 2 and counter center 3.

[0045] Washers 13 and a flap plate 20 have an anti-loosening function.

[0046] A shim 22 can also be placed between the spacer 10 and a plate 11.

[0047] According to another embodiment of the invention, it can be provided that the plates 11 have a hardness similar to that of the rails used to manufacture the center 2 and tailstock 3. For example, the plates 11 can be made of the same steel as these rails.

[0048] According to another preferred embodiment of the invention, the mounting of the movable point at its rear end can be achieved with parts specially configured to allow dismantling of the movable point without having to remove the cradle, as described for example in document EP1741830. This makes it possible for example to replace the movable point 1 in track in one night, without having to replace an entire movable point frog when in particular the front end of the movable point 1 is worn.

[0049] The fact that blocks 6, 7 are removable makes it easier to remove the movable tip 1, even in the presence of an extension 8 and housings 9 as described above.

[0050] According to another embodiment of the invention shown in Figures 5 and 6, the operating device comprises at least one bistable elastic device 15, connecting said movable tip to a fixed point, for example said hare's foot. Such a bistable elastic device 15 is disposed along the movable tip 1 behind its front end, to replace a secondary drive, thereby reducing its number and ideally eliminating them all, thus avoiding the need for a linkage and / or motorization device.

[0051] We can plan to have the widest possible point and tailstock rail pads, by reducing the width of the hare's foot rail pads; thus the inertia of the point is improved and can in some cases allow the use of more bistable elastic devices 15, and fewer secondary attacks by linkage.

[0052] A bistable elastic device 15 may, for example, comprise two rods 16 of variable length, each equipped with a spring 17 exerting an elastic force on it in the direction that extends its length. The two rods 16 are arranged articulated at their ends, one end to a fixed point 19, the other end to a point attached to a bar 18 configured to push the movable tip either towards its straight track position or towards its diverging track position.

[0053] When the operating device exerts an operating force at the front end of the movable point 1, the latter deforms, and carries the bar 18 until the bistable elastic device 15 passes beyond its equilibrium point; for example on laou 6, the end of the rods 16 fixed to the bar 18 passes beyond the line formed by the fixed points 19. The bistable elastic device 15 then begins to exert a force in the direction of the operation, and thus exerts an assistance in the movement of the movable point and a holding force in position, this in the direction of the movement of the movable point towards its straight track position on the one hand, or towards its diverging track position on the other hand.

[0054] According to a particular embodiment of the invention, a movable tip lock can be disposed in the vicinity of the front end of the movable tip 1.

[0055] According to a preferred embodiment of the invention, the rail profiles used for manufacturing the frogs are profiles of the same height as the rail of the main track into which the frog is intended to be integrated; preferably, the profiles are identical. This has the advantage of not requiring forging the frog's rail end to perform welding to the adjacent rail.

[0056] According to another preferred embodiment of the invention, the rail profiles used for manufacturing the center and center are profiles of the same height as the rail of the main track into which the frog is intended to be integrated; preferably, the profiles are identical. This has the advantage of not requiring forging of the center and center rail base to perform welding to the adjacent rail.

[0057] According to a preferred embodiment of the invention, blocks 6 and 7 are equipped with measuring sensors, in particular an accelerometer, a vibration sensor, or a positioning or displacement detector. Having such sensors on blocks 6 and 7 facilitates their modularity, installation, and maintenance, thanks to the demountable nature of blocks 6 and 7.

[0058] Although the above description is based on particular embodiments, it is in no way limiting of the scope of the invention, and modifications may be made, in particular by substitution of technical equivalents or by different combination of all or part of the features developed above.

Claims

A movable-point crossing frog for railway track, comprising: a cradle having a straight track frog and a diverging track frog, each fitted with at least one rail; a movable-point assembly, having a fixed heel forming the straight track and the diverging track, and a movable-point disposed between said two frogs; a shunting device configured to move the movable-point between a straight track position, pressed against a straight track frog, in which it forms the continuity of the rolling, between said frog and the straight track of the fixed heel, and a diverging track position, pressed against a diverging track frog, in which it forms the continuity of the rolling, between said diverging track frog and the diverging track of the fixed heel; said movable-point assembly having a point rail extending to the movable-point.and a tailstock rail assembled laterally to said tailstock rail, characterized in that at least one tailstock foot comprises a block, fixed to said at least one rail on the side of the tailstock foot oriented towards said movable tailstock, the top of said block being arranged lower than the top of said rail so that a wheel passing over said hearth is carried by said rail and guided but not supported by said block. Crossing heart according to claim 1, wherein the movable point has at its front end a vertical extension away from the rolling surface, and said block has a housing, said extension and housing being configured so that when the movable point is in its position pressed against said hare's foot, said housing constitutes a vertical stop for said extension and thus prevents the lifting of the movable point. Crossing heart according to at least one of the preceding claims, wherein said block is made of a material having a hardness greater than that of said rail, preferably a hardness of at least … Crossing heart according to at least one of the preceding claims, wherein the two hare legs each comprise a block as claimed in claim 1, and the block of the straight track hare leg is connected to the block of the diverging track hare leg, the two blocks forming a single piece. Crossing heart according to at least one of the preceding claims, wherein the block and / or the moving tip assembly is configured so as to be removable on track, without requiring dismantling of the cradle. Crossover core according to at least one of the preceding claims, wherein said block is equipped with measurement sensors, in particular an accelerometer, or positioning or displacement detector. Crossing heart according to at least one of the preceding claims, wherein the height of the rail profiles is the same for the running track rails and the rails of the two hare's legs. Crossing heart according to the preceding claim in which the rail profile is the same for the running track rails and the rails of the two hare's legs. Crossing heart according to at least one of the preceding claims, wherein the movable point comprises a first rail forming the point, and a second rail forming the counterpoint, and the height of the rail profiles is the same for the running track rails and the rails forming the point and the counterpoint. Crossing heart according to the preceding claim in which the movable point comprises a first rail forming the point, and a second rail forming the counterpoint, and the rail profile is the same for the running track rails and the rails forming the point and the counterpoint. Crossing core according to at least one of the preceding claims, wherein the movable point comprises a first rail forming the point, and a second rail forming the tailstock, and the means for assembling the tailstock to the point comprises a spacer configured to guarantee a sliding clearance between the point and the tailstock, preferably a sliding clearance of a value between 0.05 and 4 mm, preferably between 0.2 and 0.4 mm. Crossing heart according to at least one of the preceding claims, wherein the operating device comprises at least one bistable elastic device, disposed between said movable point and said hare's foot, and configured to exert an aid to the movement of the movable point and a holding force in position, this in the direction of the movement of the movable point towards its straight track position on the one hand, or towards its diverging track position on the other hand. Crossing heart according to at least one of the preceding claims, wherein the two hare's legs each have a straight portion of at least 20cm, preferably at least one meter, in length, and the straight portions of the two hare's legs are arranged face to face in the crossing heart so as to form a straight section, preferably encompassing the position of the end of the movable point. A method for replacing a moving point of a crossing frog according to any one of claims 1 to 11, with a new moving point, comprising the following steps: uncoupling said operating device and said moving point; removing at least one block; removing stops and fixings from the rear end of the moving point; cutting welds between the point on one side and the tailstock on the other with rails; removing the moving point; installing a new moving point

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