This is a national stage filing in accordance with 35 U.S.C. § 371 of PCT/EP2015/076766, filed Nov. 17, 2015, which claims the benefit of the priority of German Patent Application No. 102014117047.7, filed Nov. 21, 2014, the contents of each are incorporated herein by reference.
Cross member for rail vehicles for linking of a rail carriage body to its bogie
The invention relates to a cross member for a rail vehicle according to the respective generic term of claims 1, 12, 15 and 18.
Rail vehicles in the sense of the present invention are both rail-bound vehicles with and without their own drive. The special feature of such vehicles is their rail-bound control through the track, which when driving along curves entails relative movements of the landing gear to the carriage body due to the length of the rail vehicles. Simultaneously during a journey, rolling and snaking movements as well as braking and traction forces occur between chassis and carriage body, which require special structural measures in the connection area between chassis and carriage body.
Rail vehicles known for this purpose have, as a supporting component, a cross member made of aluminium casting mounted on the lower side of the carriage body or the box undercarriage, which is hinged to a chassis designed as a bogie. The connection is made via a steel pivot pin, which is fastened centrally to the underside of the cross member by means of a pivot plate which is likewise made of steel and is hinged to the bogie for force transmission in a pivot pin socket mount. The weight of the carriage body is thereby supported by springs disposed between the bogie and the carriage body.
This type of linking enables, on the one hand, a secure transmission of braking and traction forces, while on the other hand, the rotary and rolling movements of the carriage body caused by the driving operation are permitted against the bogie but these are limited for reasons of driving safety and comfort. For this purpose, it is known to counteract the rolling movements by means of a roll damping between the bogie and the cross member and the rolling motion by means of a roll damping between the bogie and the cross member.
Known cross members are cast from suitable aluminium alloys. They are designed as a pressure-resistant hollow body and have the shape of a plate with essentially flat tops and bottoms, on which all necessary structural elements for the connection of the carriage body to the bogie are mounted. The cavity inside the cross member is used as additional air reserve for air suspension. In known cross members, a distinction is made between head cross members, which are provided on the first and last bogie of a train formed by a plurality of rail vehicles, and base cross members, which are arranged at bogies lying in between. The present invention relates to both head cross members and base cross members.
In the case of known rail vehicles, the securing of pivot pin to the cross member has proved to be problematic. Due to the integration of the pivot pin into a pivot pin plate with side stops arranged on the side of the pivot pin, different thermal expansions occur due to the different material-specific coefficients of thermal expansion of steel and aluminium in case of large temperature fluctuations, which produce high shearing forces, especially in the contact surface between the cross member and the pivot pin plate. The fastening means, which are located in the edge region of the pivot plate are thus subjected to extreme loads at great temperature differences, which has already led to a failure of the fastening means for the pivot plate.
A further problem of the known cross members relates to the linking of the roll dampers and winder dampers to the cross member. On the underside of a cross member in the region of the transverse sides, winder damper brackets are screwed, the free ends of which support winder damper head each for linking a winder damper. Due to the geometrical conditions, forces from the winder damper generate high torques in the fastening region of the bracket, which must be absorbed by the screws there and must be taken into account by corresponding dimensioning.
The roll dampers are retained, via a roll bearing rod, at the roll bearings arranged on both sides to the cross-member transverse sides. Known roll bearings consist of an attachment cast on the cross member with a first bearing surface for including the roll bearing rod and a bearing shell with a second bearing surface. To form the roll bearing, the bearing shell is screwed to the attachment, whereby the joining surface extends approximately parallel to the plane of the cross member. The forces which are introduced into the roll bearing via the roll bearing rod from the roll damper lead to very high material stresses in the connection area of the attachment to the cross member, which requires suitable structural measures.
In the case of air-cushioned mounting of the carriage body, the air volume required for the suspension in known rail vehicles is set by the cross member designed as pressure vessel and by the cavity of the rubber-bellows-shaped air springs between the bogie and the cross member. It has been found that the size of the total air volume has a decisive influence on driving safety and driving comfort.
A rail vehicle is described in DE 10 2012 105 310 A1, in which a spring device is provided with a first and second contact element, which comprises a spring unit and is arranged kinematically in series between the carriage body and the running gear unit. DE 198 26 448 C2 also describes a running gear for a rail vehicle, in which the driven pair of wheels is mounted about a common vertical axis and the non-driven individual wheels are pivoted about their own vertical axis respectively; and in which the non-driven individual wheels are coupled with one another using a steering mechanism for a common equilibrium swivelling about their vertical axes. DE 197 51 742 C2 describes a rail vehicle, in which the linking devices are designed in such a way that the drive after exceeding the traction, braking and guide forces which are to be transmitted operationally by the linking device, makes contact at the main frame or frame-tight stops with the interposition of energy-absorbing end-stop elements. However, in terms of driving safety and driving comfort, these cross members can still be improved upon, particularly with regard to their use in areas with high temperature fluctuations.
Against this background, the object of the invention is to further improve known cross members, in particular with regard to their influence on driving safety and driving comfort of rail vehicles equipped therewith, as well as their use in areas with large temperature fluctuations. This object is achieved by means of a cross member having the features of patent claims 1, 12, 15 and 18.
Preferred embodiments are derived from dependent claims.
A first basic idea of the invention is manifested in the concentration of the load-bearing connecting and fastening elements in the narrower circumference region around the axis of the pivot pin. In doing so, thermal expansions between the fastening points as a result of temperature differences have only a small effect such that these can be trapped with tolerances. Rail vehicles with cross members according to the invention are, therefore, usable in areas with large temperature fluctuations of, for example, 50° to −55°.
In a preferred embodiment of the invention, it is provided to assign different load-bearing means to the different stresses acting simultaneously on the connecting area. Thus, braking and pulling forces are removed by a form-fit in the area of the joining surfaces between the pivot plate and the cross member, with the advantage that material stresses are limited by the enlarged force transmission surfaces despite the concentrated load transmission in the pivot post axis. On the other hand, forces from lifting and lowering movements are absorbed in the pivot axis by means of tensioning screws, which are grouped at a narrow radial distance about the axis of the pivot pin. Advantageously, the radial spacing of the clamping screw axes relative to the pivot axis is an optimum distance, which stems from the results of the FEM-calculations. In the present exemplary embodiment, this distance amounts to maximum 80 mm. In a preferred manner, the tensioning screws are arranged within the cross-section of the form-locking means, in order to keep the restraints due to different thermal expansion as low as possible.
In the case of such a connection of the pivot plate to the cross member, tensioning screws are only axially stressed, while bending stresses and shear forces are absorbed via the form-fit. The clamping force of the tensioning screws can, therefore, be used to the maximum extent.
The tensioning screws are advantageously anchored via an abutment plate, on which the screw heads are supported. In this way, point load concentrations on the cross member are avoided in the area of the screw heads. The abutment plate distributes these point loads over the entire contact surface on the cross member.
In the case of an exceptionally high load on the connecting region, for example in the case of an impact or accident, an embodiment of the invention is preferred, in which the pivot plate is additionally supported on the side of the pivot pin on the underside of the cross member. Due to geometric conditions, an improved leverage effect takes place in such a load case, whereby it is possible to absorb even acceleration forces in an order of magnitude of five times the acceleration force.
In the case of such a lateral support, the pivot plate remains functional even at high temperature fluctuations, in a further embodiment of the invention, the lateral support is provided in the mounting areas floating on the underside of the cross member. A preferred embodiment of the invention provides for the use of spacer bushings, which are arranged in oblong holes on the pivot plate and below the intermediate connection of a sliding layer into the pivot plate and are penetrated by fastening screws which, in turn, engage in the underside of the cross member.
An additional fixing of the pivot plate against a displacement in the longitudinal axis of the cross member is effected according to a preferred embodiment of the invention by the arrangement of skirting boards along the longer sides of the pivot plate. Advantageously, the skirting boards are cast on the underside of the cross member and pass monolithically into the side stops, so that the pivot plate made of steel can be kept as small as possible, with the further advantage of reducing the weight compared to known cross members.
A further basic idea of the invention is to embed function components, such as, for example, the winder damper bracket or the side stops, which are screwed onto the flat underside of the cross member in the case of known cross members, from now on monolithically to the cross member. This initially has the considerable advantage that, when designing the winder damper bracket and/or the side stops as hollow bodies, whose cavity supplements the air volume provided by the cross member for the air suspension, which positively affects the driving safety and the driving comfort of a rail vehicle.
With regard to the connection of the winder damper bracket to the cross member, it is also preferred that fasteners, which were subjected to high stress in known cross members due to unfavourable lever ratios, are now no longer necessary because of the monolithic design.
A further basic idea of the invention relates to the roll bearings, the known cross-members of which have a two-part design with horizontal separation to extremely high material stresses in the transition region of the roll bearing to the cross member. As a result of the path of the joining surfaces according to the invention transverse to the plane of the lower or upper cross member side, an enlarged cross-section for the load introduction of the bearing forces into the cross member is provided in an astonishingly simple way, with the result that stress peaks in this area are significantly reduced.
Finally, a further basic concept is contained in a cross member according to the invention, correspondingly the cast contours in the regions between the bearing surfaces, the pivot post plate and the embed anti-rolling damping brackets are designed at a higher level than the bearing surfaces. For example, the level difference between the bearing surfaces and the raised regions can be 30 mm and more, preferably 50 mm and more. This leads initially to the fact that the increased overall height of the cross-member forces can be better absorbed and derived due to greater internal lever action. This allows the design of cross members with significantly lower wall thickness, which in turn is advantageous when the cross member is cast, since the finished aluminium casting has a finer grain structure and is, therefore, characterized by a better material quality.
Since the surface contours are also marked on the inner side of the cross member, which delimits the cavity, an additional air volume for the air suspension is provided with the raised areas, which, as described, brings about driving safety and the driving comfort of a rail vehicle equipped with a cross member according to the invention. At the same time, the raised areas on the underside of the cross member form a border for the seat of the air springs and thus provide improved support and secure seating of the air springs on the cross member. The invention is explained in detail below with reference to an exemplary embodiment shown in
Ways of Working the Invention and Commercial Usability:
Further,
The linking of the carriage body 3 to the bogie 4 is such that a pivot pin 11 extending centrally from the underside of the cross member 1 in the direction of the bogie 4 engages in the pivot pin socket on the bogie 4, in order to be able to transfer the braking and tensile forces between the bogie 4 and the vehicle body 3, without having to hinder the relative movements in the form of turning, lifting, lowering, tilting and rolling movements.
In order to dampen the relative movements mentioned between the bogie 4 and the carriage body 3, as shown in
The two roll dampers 13 are linked by means of a roll bearing rod 17, the ends of which are supported on both sides in roll bearings 18 fixed on the cross member 1. The connection between the roll bearing rod 17 and the roll dampers 13 is done in each case via a rotary lever 19, which sits torque-proof on the roll bearing rod 17 and the roll damper 23 is connected to its free end.
In the case of such a connection of a carriage body 3 to a bogie 4, braking and pulling forces are thus introduced into the bogie 4 via the pivot pin 11, forces from a lifting and lowering movement via the air springs 10, forces from a rolling movement via the roll dampers 13 and forces from a rolling movement via the winder dampers 14.
The precise setup of a cross member 1 according to the invention is shown in
The cross member 1 has a longitudinal axis 20 and a transverse axis 21 running perpendicular thereto. The transverse longitudinal sides 22 run parallel to the longitudinal axis 20, the cross-member transverse sides 23 parallel to the transverse axis 21. The upper side assigned to the carriage body 3 bears the reference numeral 24, the lower side facing the bogie 4 bears the reference numeral 25. On the upper side 24, the cross-member transverse sides 23 each have a fastening surface 26 for rigid connection to the carriage body 3. On the other hand, the components for the hinged connection to the bogie 4 are arranged on the underside 25. Inside, a cross member 1 according to the invention has a pressure-tight cavity, which is penetrated by a multiplicity of reinforcing ribs. The partial cavities between the reinforcing ribs are interconnected, thus forming a communicating system so that the air can flow through the entire cavity of the cross member 1.
A first subassembly for transmitting the braking and pulling forces comprises a rectangular pivot pin plate 27 made of steel, whose pivot pin 11 protrudes centrally and monolithically from the underside 28 of the latter, whose axis is designated with 29. The pivot pin 11 has a conical shape, which tapers towards the free end, with which it engages in the pivot pin socket on the bogie 4. As can be particularly seen from
For form-close mount of the pivot plate 27, the cross member 1 has a circular cylindrical clamping channel 41 extending from the upper side 24 to the lower side 25, whose inner diameter corresponds to the outer diameter of the second longitudinal section 34 of the attachment 31. In the immediate vicinity of the upper side 24 and the lower side 25, the clamping channel 41 widens to a larger diameter and thus forms a cylindrical expanded first longitudinal section 42 and second longitudinal section 43. In the region of the expanded second longitudinal section 43, the inner diameter corresponds to the outer diameter of the first longitudinal section 38 of the attachment 31, so that the pivot pin plate 27 with its attachment 31 is positively engaged by the clamping channel 41, taking into account the thermal expansion. Thereby, the annular collar 36 of the attachment 31 rests against the cross member 1, under contact to an annular bearing surface 43, formed by the radial setback of the expanded second longitudinal section 43. A play-free bearing on the annular bearing surface 43 is ensured by the fact that the first longitudinal section 32 of the attachment 31 has a larger axial extent than the expanded second longitudinal section 43, which leads to the fastening sections 38 and 39 of the pivot pin plate 27 with a slight clear distance from the underside 25 of the cross member 1.
The widened first longitudinal section 42 of the cross member 1 helps the form-fit mount of a complementarily formed abutment plate 45, which extends with a stump-shaped coaxial attachment 46 on its underside into the tensioning channel 41. The abutment plate 45 has through-holes, whose hole pattern corresponds to that of the threaded bores in the end face 37 of the attachment 1. Using the clamping screws 47, which are grouped in a narrow radial distance within the clamping channel 41 around the pivot pin axis 29 and are supported by their screw heads on the abutment plate 45, the pivot plate 27 is tightened against the cross member 1.
Such a connection of the pivot pin plate 27 to the cross member 1 concentrates the force transmission region on a small region around the pivot pin axis 29, whereby the forces in the driving mode are transferred to the cross member 1, transverse to the pivot pin axis 29 through the form closure by the first circumferential surface 33 and second circumferential surface 35, and forces in the direction of the pivot pin axis 29 are absorbed by the annular bearing surface 44 or the threaded bolts 47.
The relative position of the pivot pin plate 27 to the cross member 1 is such that the fastening sections 38 and 39 are aligned in the transverse axis 21 of the cross member 1. This has the advantage that the fastening sections 38 and 39 contribute to the force transmission in the case of extraordinary shock loads, for example, during an impact or accident. In order to prevent damage to the pivot pin plate 27 as a result of high special loads, even under the conditions of low temperature factors, the fastening sections 38, 39 are fastened floatingly to the cross member 1, which means that a support of the fastening sections 38, 39 is perpendicular to the underside 25 of the cross member 1, while relative movements of the pivot pin plate 27 opposite the cross member 1 are possible in the plane of the underside 25.
As can be seen especially from
On both sides of the pivot pin plate 27, skirting boards 56 run parallel to the transverse axis 21 of the cross member 1. The skirting boards 56 extend monolithically from the underside 25 of the cross member 1 and include the pivot pin plate 27 in a positive-locking manner in the space formed in between (
In the middle region of the skirting boards 56 at the level of the pivot pin 11, a side stop 57 is in each case cast monolithically on the skirting board 56. The two side stops 57 are thus extended on both sides of the pivot pin 11 and run parallel to this from the underside 25 of the cross member 1 and are ran thus separated from the pivot pin plate 27. As is particularly evident from
In the area of the two transverse sides 23, at the underside 25 of cross member 1 one winder damper bracket 16 each is cast, with a wide base that tapers towards the free end and a flat bearing surface 58 is available there for mounting a winder damper head 15. The winder damper bracket 16 is designed similar to the side stop 57 as a hollow body, whereby the cavity of the cross member 1 and the cavity of the winder damper bracket 16 merge again into each other and result in a total void.
At the ends of the cross-member transverse sides 23 opposite the winder damper brackets 16, a roll bearing 18 is arranged in each case, in which one end of the roll bearing rod 17 is pivoted. The roll bearing 18 is divided and includes an attachment 59 cast onto the cross member 1 with a first bearing surface, and a loose bearing shell 60 with a second bearing surface, which is stretched for forming the roll bearing 18 by means of screws against the attachment 59. It can be seen from
The cross member regions between the side stops 57 and the winder damper bracket 16 and roll bearing 18 form the respective bearing surfaces 62 for the air springs 10. The bearing surfaces 62 have a circular shape and are provided with port openings 63 to the cavity of the cross member 1. The area of the cross member 1 lying between the bearing surfaces 62 is designed raised relative to the bearing surfaces 62, whereby a border 64 of the bearing surfaces 62 is formed. Inside the cross member 1 the raised regions lead to a cavity enlargement.
Number | Date | Country | Kind |
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10 2014 117 047 | Nov 2014 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/076766 | 11/17/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2016/079090 | 5/26/2016 | WO | A |
Number | Name | Date | Kind |
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763278 | Green | Jun 1904 | A |
1114209 | Westlake | Oct 1914 | A |
20020158381 | Foerster | Oct 2002 | A1 |
Number | Date | Country |
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19751742 | Nov 1999 | DE |
19826448 | Jul 2001 | DE |
102012105310 | Dec 2013 | DE |
0775621 | May 1997 | EP |
Number | Date | Country | |
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20180141572 A1 | May 2018 | US |