Self-propelled machine for stabilizing by hammering and compacting, tracks laid on ballast

Abstract: The machine is constituted by a self-propelled truck (10) which comprises a first hammering unit (16) and a second compacting unit (17). The first unit comprises mutually opposite sets (22, 23, 24) of inclined vibrating hydraulic tools which can be arranged so as to straddle each tie and are adapted to limit the migration of crushed rock from the tamping regions of the ballast, which lie below each tie, to the intermediate ballast regions which lie between two consecutive ties. The second unit (17) is constituted by vibrating plates (50), which are also actuated hydraulically and are adapted to compact the crushed rock located in the layer above the laying plane of the ties in the intermediate ballast regions (B) and on the heads of the ties. The first and second units (16, 17) are supported by a portal-shaped chassis (15-15a) of the car (10), are mutually spaced by an extent which is a multiple of the various spacing pitches of the ties of the track, and are arranged so that during working travel of the car the first unit (16) precedes the second unit (17).

Description: The present invention relates to a self-propelled machine for stabilizing tracks laid on ballast. After repairs to the geometry of tracks, usually performed by means of tamping, aligning, and leveling machines, ballast settling conventionally occurs when the first trains pass; this settling is characterized by the migration of the crushed rock from the tamping region below each tie towards the upper part of the ballast in the intermediate region and towards the heads which lie externally with respect to said ties. The enclosed figures 1 and 1a schematically show said settling of the crushed rock which, due to the passage of the trains C on the track BI, migrates partially from the tamping region A below the ties T 1 , T 2 ,..., T n in the upper part of the region B of the ballast which lies between two consecutive ties T 1 -T 2 , and simultaneously, due to the hunting of the trains, towards the head regiors C (figure 1a). This settling produced by the migration of the crushed rock in the specified direction is followed by a variation in the level of the track in the longitudinal plane (change in the elevation of the rolling plane) and by a deflection of said track in the transverse plane or plane of arrangement (lateral deflection and/or misalignment), with a consequent alteration of the geometric characteristics of the track which is not compatible with the travel comfort and is correlated to the transit speed of modern trains. The operations for restoring and regenerating railroad ballasts must therefore be followed by one or more track stabilizing operations aimed at preventing the uncontrolled settling of the regenerated ballast produced by the passage of trains. Track stabilizing machines already exist for this purpose which act by vibration on said track but have several disadvantages, the main one being the generation of intense stresses on the systems for coupling the rail and the tie to each other and the more or less extensive modification of the track laying geometry. Moreover, these conventional machines are necessarily limited in their use, since the intensity of the shaking vibrations transmitted by said machines to the track causes stability problems for the static structures lying adjacent to the railroad, particularly to buildings, bridges, overpasses, underpasses, level crossings, and to the moving elements of tracks such as switches, junctions, and the like, so that said conventional machines are unable to perform adequate work over entire stretches of the railroad. FR-A-2 302 383, FR-A-2 155 420, and DE-A-2 114 282 each disclose a self-propelled machine for stabilizing tracks laid on ballast including a combination of features as set forth in the precharacterizing portion of the appended claim 1. A principal aim of the present invention is substantially to eliminate these and other drawbacks of conventional stabilization systems, and within the scope of this general aim said invention has the important object of providing a self-propelled machine which is capable of performing track stabilization by acting only on the ballast, therefore maintaining the laying geometry of the rail on the one hand and eliminating undesirable stresses on the rail-tie connecting systems on the other hand. The invention also has the purpose of providing a self-propelled stabilizing machine which can be used on any stretch of railroad and even close to buildings and structures adjacent to the railroad path. Another important object of the invention is to provide a track stabilizing machine which is reliable in operation, structurally simple, and capable of acting even in the presence of switches, track junctions, level crossings, etcetera. According to the invention, this aim and other important functional objects are achieved with a machine having the specific characteristics described in the appended claims. Substantially, the invention is based on the concept of using a self-propelled car which has a first hammering unit formed by pairs of vibrating hydraulic tools which are supported by a portal-shaped framework of the car and can be arranged so as to straddle each tie and at the heads of said ties. Said vibrating tools of the hammering unit are slidingly supported on corresponding inclined guides and by virtue of the action of movement jacks they move along respective advancement paths which intersect in an imaginary point which lies below the involved tie, in the above-mentioned tamping region A. With this arrangement, the hydraulic tools of the hammering unit produce, by means of their vibration, on the one hand the compaction of the crushed rock in the tamping region below the tie and, on the other hand, the migration of the excess crushed rock in the region B which lies between two consecutive ties, said region being the one which has the lowest crushed-rock density. In this manner, in said intermediate regions the crushed rock rises beyond the plane of arrangement of the ties and is subjected to subsequent compaction by means of a second compaction unit formed by vibrating plates, which are also supported by the portal-shaped framework of the self-propelled car. The hammering tools and the compaction plates can be spaced from each other by an extent which is a multiple of the spacing pitch of the ties installed in the specific stretch of track being treated, and the plates come after the tools with reference to the advancement motion of the car, so as to be able to compact the crushed rock lifted by the preceding action of the hammering tools. Further characteristics and advantages of the stabilizing machine according to the invention will become apparent from the following detailed description and with reference to the accompanying drawings, given by way of non-limitative example and wherein: figures 1 and 1a are schematic views of the crushed rock settling movement of a conventional non-stabilized railroad ballast when trains pass, taken respectively longitudinally with respect to the track and transversely thereto; figure 2 is a schematic elevation view of the stabilizing and compacting machine according to the invention; figure 3 is a top plan view of figure 2; figure 4 is a schematic partial perspective view of the hammering unit; figure 5 is a detail lateral elevation view of the first unit of figure 4; figure 6 is an enlarged-scale partial front sectional view, taken along the plane VI-VI of figure 3; figure 7 is a schematic view, similar to figure 1, of the distribution of the crushed rock of the ballast after the action of the hammering unit of figure 4; figure 8 is an enlarged-scale front elevation view of a detail of the second compacting unit; figure 9 is a plan view of the compaction unit, taken in the direction of the arrows IX-IX of figure 8; figure 10 is a transverse sectional view, taken along the plane X-X of figure 9; figures 11, 12, and 13 are views, similar to figures 2, 8, and 9 respectively, of a constructive different embodiment of the machine according to the invention; figure 14 is a sectional view, taken along the plane XIV-XIV of figure 13. With reference to figures 2 to 10, the machine according to the invention is constituted by a self-propelled car 10, provided with pairs of wheels 11-12, at least one of said pairs being a driving pair, and with a powerplant 13 which provides the power required both for the movement of the car 10 and for the actuation of one or more hydraulic pumps 14 which supply the various fluid-actuated actuators described hereinafter. The self-propelled car 10 has a chassis 15 with a central portal-shaped raised portion 15a which supports a first hammering unit, shown schematically in figure 2 and generally designated by the reference numeral 16, and a second compacting unit, also shown schematically in figure 2 and generally designated by the reference numeral 17. Both units 16 and 17 are supported by the chassis 15 with the interposition of respective vertical movement devices. In particular, the unit 16 is supported with the interposition of a respective articulated frame 18 provided with at least one movement jack 20, in order to arrange it in a raised position (not shown) during the travel of the car 10, or in a lowered operating position (figure 2) in which said unit rests, with two of its own supporting wheels 16a, on the track BI. Likewise, the unit 17 is supported by an articulated structure which is subjected to a vertical movement jack 21 for the same purposes. With reference to figures 4, 5, and 6, it is noted that the hammering unit 16 is formed by mutually opposite sets of vibrating hydraulic tools 22, 23, and 24; the first two are formed, for example, by four tools each and are aligned transversely with respect to the track BI, and the third one is formed by two mutually opposite tools located at the head of each tie T. Each tool comprises a hammer 25 which has an end plate 25a and is moved in a reciprocating fashion by a corresponding double-action hydraulic jack 26 at a rate and with a stroke which can be adjusted by the operator or by programmable electronic control means. The hydraulic jacks 26 are powered by a hydraulic circuit (not shown) by means of electric distribution valves of the two-way type, the solenoids whereof are energized in a cyclic fashion by a variable-frequency oscillator or, as an alternative, by a rotary mechanical distributor which is driven by an adjustable-speed electric motor according to supply circuit arrangements which are both known and are disclosed in prior Italian patent no. 1,219,091 (EP-A-0 331 956) in the name of SO.RE.MA S.r.l. The hydraulic tools 22, which face each other transversely to the track, are arranged mutually opposite with respect to the hydraulic tools 23, which also face each other transversely to the track, so as to form mutually opposite pairs of tools 22 and 23, which are arranged so as to straddle each tie T during work. As clearly shown in the figures, the individual vibrating hydraulic tools 22, 23, and 24 are supported by respective sliders 27, 28, and 29 which can slide on corresponding supporting guides 30, 31, and 32 and are controlled by corresponding movement jacks 33, 34, and 35, which are capable of making the corresponding tool perform an advancement stroke, which sinks the vibrating hammer 25 into the crushed rock of the ballast, and a stroke for extracting said hammer from the crushed rock. Each tool can also be individually raised to temporarily exclude it from the operating cycle, for example at switches, level crossings, and the like. The guides 30 and 31 of the pairs of mutually opposite tools 22 and 23 are inclined in opposite directions with respect to the vertical, so that the advancement paths t1-t2 of said pairs of tools converge and intersect in an imaginary point P which lies below the tie T whereon the unit 16 acts in the tamping region A shown in figure 1. Likewise, the guides 32 of the pair of head tools 24 have mutually opposite inclinations, so that the advancement paths of the respective tools also meet in a point which lies below the ties but does not necessarily coincide with the point P. The inclination of the guides 30, 31, and 32 can vary in order to adapt the hammering unit 16 to ties T having a different thickness s. Likewise, the distance (in a longitudinal direction) between the guides 30 and 31 of at least the mutually opposite pairs of transverse tools 22 and 23 can be varied in order to adapt the unit 16 to ties T having a different width L. For these purposes, the guides 30 and 31 are articulated to respective sleeves 36 and 37 by means of pivots and are actuated by hydraulic jacks 38 and 39 which allow to rotate the respective guide about its own pivoting point and to rigidly couple it with the desired inclination. In order to allow to vary the distance between the mutually opposite pairs of guides 30 and 31, the respective pivoting sleeves 36 and 37 are slidingly supported on corresponding longitudinal connecting beams 40, and each pair of mutually opposite sleeves 36 and 37 is controlled by a kinematic movement system which moves them mutually closer or further apart, making them slide simultaneously in opposite directions on the corresponding connecting beam 40, which also acts as a guide for said pair of sleeves. According to a preferred embodiment, the kinematic system comprises a central rod 41 which can rotate about a pivot 42 and has diametrically opposite ends which are connected to a corresponding sleeve by means of respective articulated linkages 43 and 44. A hydraulic jack 45 is provided in order to move the central rod 41 so that it performs a controlled oscillation. In the plane which lies transversely to the track (figure 6), the beams 40 for the longitudinal connection of the mutually opposite pairs of guides 30-31 are in turn slidingly coupled to cross-members 46 and are subjected to respective pairs of movement jacks 47 which during work move the laterally adjacent guides of each transverse set of tools 30 and 31 towards each other or away from each other, allowing the hammers 25 of said tools to act over the entire transverse extension of the ballast. In turn, the cross-members 46 comprise telescopically sliding ends 46a which are controlled by jacks 47a (figure 4) that allow to vary the axial distance of the head tools 24. The effect of the action produced by the hammering unit 16 is shown schematically in figure 7, which shows that the excess crushed rock initially present in the tamping regions A of the ballast is transferred to the region B of said ballast which lies between two consecutive ties T1-T2, and that a uniform distribution of said crushed rock is achieved, together with a simultaneous compaction of said tamping region A. As a consequence of this transfer, the crushed rock rises, in the region B of the ballast, to a level Q which lies beyond the resting plane of he ties and is therefore subjected, in said region, to subsequent compaction by means of the unit 17. For this purpose, the unit 17 is also provided with vibrating hydraulic tools, which are constituted by a plurality of plates 50 which are supported by vertical supports 51 which are shaped like an inverted U and are adapted to be arranged so as to straddle each tie T, as shown in detail in figure 10. Each support 51 is provided with retaining uprights 52 which are slidingly guided in corresponding bushes 53 supported by a supporting cross-member 54, which is rigidly coupled to the vertical movement device described above. Each support 51 is subjected to the action of a corresponding vibrating hydraulic jack 55, which is interposed between said support and the supporting cross-member 54, and the plurality of jacks 55 is supplied by the same hydraulic circuit that supplies the set of vibrating tools of the hammering unit 16; the extent and rate of vibration of the jacks 55 can therefore be easily varied over a wide range, particularly by merely adjusting the manual oscillator or the electronic control, if said supply circuit is of the type with electric distribution valves. Moreover, with the described system provided with vibrating jacks 55 one also obtains a perfectly axial thrust on the plates 50 which cannot be obtained with the eccentric-mass vibrating systems of conventional compacting units. Preferably, two additional lateral plates 56a-56b are also arranged at the mutually opposite ends 54a-54b of the cross-member 54; each one of said plates is directly pivoted to the ends of the stems of corresponding pairs of vibrating jacks 57a-57b and is adapted to be arranged at an angle in order to compact the corresponding ballast slope. As an alternative, the vibrating jacks 57 can be supported by the cross-member 54 at an angle and their stem can be arranged at right angles to the plane of the respective ballast slope. According to the embodiment of figures 11 and 14, the arrangement of the hammering and compacting units 16' and 17' is reversed with respect to the chassis 15 of the car 10', so as to allow easier monitoring of the work of the hammering unit from the cabins of said car, which in this case travels in the opposite direction with respect to the car of figure 2. Moreover, according to this embodiment, each U-shaped support 51 of the unit 17' is subjected to the direct action of a corresponding vibrating hydraulic jack 55, which is articulated to the fork-like end of a corresponding arm 19a of the supporting structure 19', and each arm is subjected to a respective jack 21' for individual vertical movement. The ends of the individual arms 19a which Lie opposite to the ends provided with the jacks 55 are articulated to respective carriages 58 provided with mutually opposite wheels 58a and movable on guiding and supporting cross-members 59 in order to adjust their transverse position, the carriages 58 being subjected to individual transverse adjustment jacks 60. The cross-members 59 are in turn supported, so that they can move longitudinally, by pairs of mutually opposite longitudinal members 61, which allow both the longitudinal adjustment of the unit 17' with respect to the chassis 15 and a limited steering of said unit about a contrast pivot 62. The longitudinal adjustment and the steering of the entire unit are performed by means of a pair of jacks 63 which are actuated simultaneously or respectively in a differentiated manner. On the side lying in front of the arms 19a, the structure 19' continues with a subvertical central rigid beam 64, and two telescoping arms 65 are articulated to the lower end of said beam; said arms have, at their respective ends, mutually opposite vibrating jacks 66a-66b which are directly connected to corresponding vibrating plates 67a-67b which are arranged at an angle in order to compact the corresponding ballast slope. The length of the arms 65 can be adjusted through respective hydraulic jacks 68 and their inclination can be adjusted by means of corresponding hydraulic jacks 69 which are arranged vertically. According to the described second embodiment, in the unit 17', too, each pair of compacting plates 50 can be raised easily and individually through the actuation of the corresponding jack 21' in order to temporarily exclude it from the working cycle according to the different operating requirements. The hammering unit 16 and the compacting unit 17, arranged one in front of the other, with reference to the motion of the car 10-10' indicated by the respective arrows in figures 2 and 11, are spaced one from the other by an extent which is a multiple of the different spacing pitch of the ties T of the track, so that the compacting unit can act after the hammering unit in order to compact the crushed rock moved by said hammering unit. Without altering the concept of the invention, the details of execution and the embodiments may of course be altered extensively with respect to what has been described and illustrated by way of non-limitative example without thereby abandoning the scope of the invention as defined in the claims. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims: A self-propelled machine for stabilizing tracks laid on ballast, comprising a self-propelled truck (10, 10') which comprises a first hammering unit (16, 16') and a second compacting unit (17, 17'); the first unit comprising mutually opposite sets (22, 23, 24) of inclined vibrating hydraulic tools which can be arranged so as to straddle each tie and are adapted to limit the migration of crushed rock from the tamping regions (A) )f the ballast, below each tie, to the intermediate ballast regions (B) between two consecuti ve ties; and the second unit (17) being constituted by vibrating plates (50-56a- 56b), which are also actuated hydraulically and are adapted to compact the crushed rock placed in the layer above the laying plane of the ties in said intermediate ballast regions (B) and on the heads of the ties (C), characterized in that the individual vibrating hydraulic tools (22, 23, 24) of the hammering unit (16) are each supported by respective sliders (27) which can slide on inclined guides (30) and are subjected to the action of corresponding movement jacks (33); and in that said vibrating tools are movable along respective advancement paths (t1-t2) which are inclined in opposite directions with respect to the vertical such that said paths mutually intersect below each track tie (T) in an imaginary point (P) variable at will. A machine according to claim 1, characterized in that said first and second units (16, 17) are supported by a portal-shaped chassis (15-15a) of the car (10), are mutually spaced by an extent which is a multiple of the different pitches used in railroad, subway, and tram lines for spacing the ties (T) of the track (BI), and are arranged so that during the working motion of the self-propelled truck (10) the first unit (16) precedes the second unit (17). A machine according to claim 2, characterized in that said first and second units (16, 17) are supported by said portal-shaped chassis (15-15a) with the interposition of respective vertical movement devices (18, 19, 19') which are adapted to arrange said units in a raised transfer position or in a lowered working position. A machine according to claim 3, characterized in that said movement devices (18, 19) are constituted by articulated frames, can be deformed by means of corresponding movement jacks (20, 21), and can be locked mechanically in a raised position. A machine according to claim 1, characterized in that said hammering unit comprises at least two sets (22-23) of mutually opposite vibrating tools which are arranged transversely to the track and can be arranged so as to straddle each tie (T) regardless of the size of said tie and of the presence of large ties and/or double ties, and two mutually opposite tools (24) arranged at the heads of said ties. A machine according to any of claims 1 to 5, characterized in that each vibrating hydraulic tool comprises a hammer (25) which is moved in a reciprocating manner by a corresponding double-action hydraulic jack (26) at a rate, and with a stroke, which can be adjusted directly by the operator or be adjusted automatically by programmable electronic control means. A machine according to claim 6, characterized in that the double-action hydraulic jacks (26) of said vibrating hydraulic tools (22, 23, 24) are supplied by a hydraulic circuit, which comprises two-way electric distribution valves energized by an adjustable-frequency oscillator or comprises a single rotary distributor actuated by an adjustable-speed motor. A machine according to claim 1, characterized in that it comprises means (38, 39) for varying the inclination of the guides (28) for the sliding of the vibrati ig hydraulic tools (22, 23, 24), means (36, 37, 40, 41, 42) for varying the longitudinal distance between the pairs of tools (22, 23, 24), and means (46, 47, 47a) for varying the mutua transverse axial distance between the tools of each set. A machine according to claim 8, characterized in that the guides (28) for the sliding of the pairs of mutually opposite vibrating hydraulic tools (22, 23) are articulated to respective sleeves (36, 37) and are subjected to hydraulic jacks (38-39) which allow to rotate said guides about the respective pivoting point and to rigidly couple them to the respective sleeve with the desired inclination. A machine according to claim 9, characterized in that the pairs of mutually opposite sleeves (36, 37) for the pivoting of the guides (28) can slide on respective longitudinal beams (40) and are subjected to a kinematic movement system which moves them mutually closer or further apart, making them slide simultaneously in opposite directions on said beam (40). A machine according to claim 10, characterized in that said kinematic movement system comprises a central rotating rod (41) the diametrically opposite ends whereof are connected, by means of respective articulated linkages (43, 44), to a corresponding sleeve (36, 37), a hydraulic jack (45) being provided in order to move said central rod (41) by controlled oscillation. A machine according to claim 9, characterized in that said longitudinal beams (40) are in turn slidingly rigidly coupled to cross-members (46) and are subjected to hydraulic jacks (47) adapted to vary the axial distance between the laterally adjacent guides of each set (22, 23) of vibrating hydraulic tools, allowing the hammers (25) of said tools to act on the entire transverse extension of the ballast. A machine according to claim 12, characterized in that the cross- nembers (46) have telescoping ends (36a) subjected to actuation jacks (47a) which allow to vary the axial distance of the pairs of end tools (24). A machine according to claim 1, characterized in that the second compaction unit (17) comprises a plurality of vibrating toothed plates (50) supported by supports (51) which are shaped like an inverted U and are adapted to straddle each tie (T) of the track (BI). A machine according to claim 14, characterized in that each support (51) is provided with uprights (52) which are slidingly guided in corresponding bushes (53) supported by a supporting cross-member (54) which is rigidly coupled to the vertical movement device (19). A machine according to claim 15, characterized in that each support (51) is subjected to the action of a respective vibrating hydraulic jack (55), which is interposed between said supporting cross-member (54) and said support; and in that the plurality of jacks (55) which act on said supports (51) is supplied at rates and with strokes which can be adjusted by the same distribution circuit that supplies the vibrating tools of the hammering unit (16). A machine according to claim 14, characterized in that said second compaction unit comprises additional head plates (56a, 56b), each plate being pivoted directly to the end of the stem of a corresponding vibrating head jack (57a, 57b) and being adapted to be arranged at an angle in order to compact the corresponding ballast slope. A machine according to claim 17, characterized in that the head plates (56a, 56b) are rigidly supported by the respective head jack stem (57a, 57b), and in that said head jacks are inclined with respect to the normal with respect to the plane of the corresponding ballast slope to be compacted. A machine according to claim 1, characterized in that the hammering ing unit (16') is arranged adjacent to the control cabin of the self-propelled truck (10'), which moves in a working direction in which the hammering unit (16') precedes the compactin unit (17'). A machine according to claim 1, characterized in that the compacting unit (17') comprises compacting plates (50) which are supported by corresponding sup ports (51) shaped like an inverted U; in that each support is subjected to the direct actio of a corresponding vibrating jack (55); in that each one of said vibrating jacks (55) is articulated to the fork-like end of a corresponding movable arm (19a); and in that each arm (19a) is subjected to a respective jack (19') for vertical movement. A machine according to claim 20, characterized in that the arms (19a) which are provided with the vibrating jacks (55) at one end are articulated, at their opposite ends, to respective carriages (58) which are provided with mutually opposite wheels (58a) and are movable, in order to adjust the transverse position of each individual arm (19a), along guiding and supporting cross-members (59); said carriages (58) being subjected to the action of individual corresponding transverse movement jacks (60). A machine according to claim 21, characterized in that the guiding and supporting cross-members (59) are in turn supported, so that they can move ongitudinally, by pairs of mutually opposite longitudinal members (61) which allow both the longitudinal adjustment of the compacting unit (17') and a limited steering of said compacting unit with respect to the chassis (15) of the self-propelled truck (10'); and in that said longitudinal adjustment and/or steering are performed by means of two jacks (63) which ire actuated simultaneously or respectively in a differentiated manner. A machine according to claim 21, characterized in that the cross-member (59) for supporting the arms (19a) which bear the compacting plates (50) comprises a subvertical central rigid beam (64), two telescoping arms (65) being articulated to the lower end of said beam, said arms having, at their respective ends, mutually opposite vibrating jacks (66a, 66b) which are directly connected to corresponding vibrating plates (67a, 67b) which are arranged at an angle in order to compact the corresponding ballast slope. A machine according to claim 23, characterized in that respective pairs of hydraulic jacks (68, 69) are provided to adjust the length and inclination of the telescoping arms (65).

Inventors: MAULI ENZO, ROSSANIGO CESARE, MAULI, ENZO, ROSSANIGO, CESARE
Applicants: FERROVIE DELLO STATO SOCIETA D, SO RE MA BR FERROVIARIA S R L, FERROVIE DELLO STATO SOCIETA DI TRASPORTI E SERVIZI PER AZIONI, SO.RE.MA.<BR>FERROVIARIA S.R.L.
Application year: 1997
Main classification: E01B27
IPC codes: E01B27