Frog for railway switches and / or railway crossings, and method for producing same

Abstract

The invention relates to a method for producing a frog (1) for railway switches and / or railway crossings, having a wedge-shaped frog tip (2), wherein the frog (1) is forged as a single piece in the forging die, and two connection surfaces (4) are formed on the end face (3) of the frog (1) opposite the frog tip (2) in order to directly attach a respective connection rail (5) to each connection surface. The invention also relates to a frog for railway switches and / or railway crossings.

Description

[0001] Core component for railway switches and / or railway crossings and methods for its manufacture

[0002] The present application claims priority from German patent application No. 102025 103276.9, the contents of which are incorporated herein in full by reference.

[0003] The invention relates to a method for manufacturing a frog for railway switches and / or railway crossings.

[0004] The invention also relates to a frog for railway switches and / or railway crossings.

[0005] Track systems or rail networks, e.g. for railways or trains, include, among other things, track switches and / or track crossings to allow rail vehicles such as locomotives to change the track or reroute them as needed.

[0006] A key component of railway switches and crossings are the so-called frogs. In this context, a frog is a wedge-shaped element that brings two rails, especially two rails coming from different directions, together at an acute angle, creating a break in the track. In conjunction with other components of the switch or crossing, particularly the wing rails, the frog forms a passage for the wheels of rail vehicles, thus enabling them to switch from one track to another. The wing rails are typically attached to the frog using bolts.

[0007] The frog is subjected to exceptionally high stress compared to ordinary rails due to the almost head-on impact of the rail vehicles' wheels, which, due to their weight and speed, generate a high momentum transfer. Furthermore, the tapered frog, particularly its tip, has a comparatively thin material thickness, meaning the material must exhibit disproportionately higher resistance to the mechanical stress from the wheels.

[0008] Core components and methods for their manufacture are known in a wide variety of designs from the state of the art.

[0009] Many of the previously known frogs are manufactured using casting processes. However, practical experience has shown that cast frogs cannot withstand the stress described above sufficiently.

[0010] German patent applications DE 1 176165 B and DE 3034184 A1 each disclose a two-part frog, which is composed of a front point section and a frog point, wherein the connecting piece is welded to the front point section or the frog point. Rails or connecting rails can in turn be welded to the connecting piece. Various manufacturing processes are described for the front point section and the connecting piece.

[0011] However, the transverse weld seam within the core has a very detrimental effect on the load-bearing capacity and service life of the core.

[0012] The same applies to other state-of-the-art solutions, in which two construction rails are welded together longitudinally to form a core component.

[0013] The present invention is therefore based on the objective of creating a method for manufacturing core components which is improved compared to the prior art and in particular results in a higher load-bearing capacity and service life of the manufactured core component, as well as being cost-effective.

[0014] According to the invention, this problem is solved by a method having the features mentioned in claim 1.

[0015] The present invention also aims to create a core component that is improved compared to the prior art and in particular has a higher load-bearing capacity and service life, as well as being cost-effective to manufacture.

[0016] According to the invention, this problem is solved by a core component with the features mentioned in claim 12.

[0017] Advantageous embodiments of the inventive method and the inventive core component are shown, among other things, in the respective dependent claims and in the following description.

[0018] The inventive method for manufacturing a frog for railway switches and / or railway crossings having a wedge-shaped frog point provides that the frog is forged in one piece in a die, wherein two connecting surfaces are formed on one end face of the frog opposite the frog point in order to attach a connecting rail directly to each of them.

[0019] In other words, according to the invention, the wedge-shaped frog point and a connecting element of the frog – referred to in the prior art as a “connecting piece” – which has the connecting surfaces, are forged in one piece in a die. The frog point and the connecting element are thus monolithic or manufactured in one piece and together form at least part of the frog. Compared to the prior art, the method according to the invention allows for the production of a frog with a significantly higher load-bearing capacity and service life. This applies to the intended use of the frog, for example, as part of a railway switch or crossing traversed by rail vehicles.

[0020] The inventive method or manufacturing process allows the advantages of forging processes over casting processes and the advantages of a one-piece or monolithic design of the core to be combined in a particularly advantageous way.

[0021] The increased load-bearing capacity results, among other things, from the fact that the frog itself no longer has any welds. The connecting rails can be attached directly to the connection surfaces of the monolithic or one-piece frog, without the need for a separate connecting piece between the frog tip and the connecting rails.

[0022] Furthermore, workpieces produced by die forging generally exhibit increased strength or hardness compared to cast workpieces due to the pressure exerted during the manufacturing process. A similar principle applies compared to workpieces produced by machining processes, as these processes disrupt the fiber orientation and the natural arrangement and alignment of crystallites.

[0023] In terms of open-die forging, die forging is more scalable in terms of manufacturing technology in order to achieve higher production volumes in a reasonable time, and reduces the cost per core piece after the investment costs for the dies have been amortized.

[0024] Finally, the time required to manufacture a core piece is also significantly less in die forging, especially compared to machining processes and open-die forging.

[0025] Furthermore, the inventive method significantly reduces downtime in the field due to rework and / or maintenance measures, resulting in cost savings. In particular, the one-piece or monolithic design of the core eliminates the need for inspections or testing of the additional weld seam within the core after certain operating times in the field.

[0026] The frog can be, in particular, a frog designed as a switch frog for railway switches and / or a frog for level crossings. Railway switches and crossings serve on certain track sections to guide rail vehicles from one rail to another, in particular selectively to different rails or tracks running in different directions. Within the scope of the invention, a track or track section can be understood to mean, in particular, a pair of parallel rails.

[0027] The frog has at least one frog point. A frog for rail crossings may preferably have two frog points, which are further preferably arranged and aligned such that the respective points are opposite each other or point towards each other.

[0028] Both the frog and the frog point have an elongated basic shape, which, when used as intended, are aligned in the direction of the connecting rails or the track sections.

[0029] The wedge shape of the frog point is understood to mean a shape that tapers to a point at least substantially in the longitudinal direction of the frog. Preferably, two opposing side faces of the frog point can converge, so that, viewed from above, the side faces form an acute angle, preferably from 0.5° to 10°, and particularly from 1° to 5°. More preferably, the two side faces can also converge obliquely upwards. For further specific embodiments, reference is made to the exemplary embodiments.

[0030] Die forging is a variant of pressure forming. Within the scope of the invention, this can involve hot forming, semi-hot forming, or other forms of die forging.

[0031] In contrast to open-die forging, die forging is typically characterized by the use of a usually two-part forming tool, the die, which shapes the workpiece.

[0032] Die forging or die forming must also be distinguished from mold casting or casting processes.

[0033] The material for the workpiece, here the core component, can be any metal or metal alloy suitable for forging, especially for drop forging.

[0034] The core component is designed to be one-piece, i.e., monolithic, and in particular to have no welds.

[0035] The two connection surfaces located on the front face of the frog can optionally be formed by a single, continuous surface. A connecting rail or a track rail can be attached or welded to each of these two connection surfaces to connect the turnout or rail crossing to the rail network or tracks. The connecting rails are generally conventional rails or turnout rails. Attaching the connecting rails is not part of the inventive method. Within the scope of the inventive method, the frog to be manufactured, in particular its front face with the connection surfaces, is merely designed such that it is suitable for the direct attachment, preferably by welding, of the connecting rails.

[0036] In particular, the invention does not provide for the use of a separate connecting piece between the frog or frog point and the connecting rails. An advantage of the present invention lies precisely in the fact that such a connecting piece and the resulting additional welds can be dispensed with.

[0037] It has proven particularly suitable when the heart is normalized.

[0038] It has also proven particularly suitable when the core is finely perlited.

[0039] It has also proven particularly suitable when the core is bainitic.

[0040] Normalizing, fine pearlitizing, and bainitic treatment are types of heat treatment used to positively influence the microstructure of the material. Experts can refer to relevant DIN standards such as DIN 17022-2 (1986-06) or similar standards concerning the heat treatment and / or hardening of iron or steel materials.

[0041] After heat treatment, the material or metal may exhibit at least a partial pearlite or bainite structure. This may also be a mixed structure, such as the core of the component. Preferably, after heat treatment, the material or metal exhibits a pure pearlite or pure bainite structure.

[0042] A pearlite structure, also known as a pearlite phase, is a specific mixture of ferrite and cementite. A microstructure characterized by fine or ultra-fine striations can be described as fine pearlite.

[0043] A bainite structure or bainite step also refers to a specific phase mixture of ferrite and cementite, which differs from that of the pearlite structure, for example, in the shape, size and distribution of the crystallites.

[0044] The microstructure achievable through fine perlitizing or bainitic finishing increases the load-bearing capacity and service life of the workpiece, particularly through increased hardness or Brinell hardness (HBW) and / or increased tensile strength, preferably without impairing the material's toughness. This increased load-bearing capacity is especially important for frogs, particularly frog points, as these are subjected to exceptionally high loads and simultaneously exhibit areas with significantly reduced material thickness compared to the rails.

[0045] For fine perlitizing or bainitic treatment, normalizing heat is preferably utilized, as will be explained in more detail below. This approach is particularly advantageous because it can be carried out on the raw part itself and not only on the finished workpiece or frog. Furthermore, this allows the microstructure to be improved throughout the entire frog, and not just in a head area or on the running surface.

[0046] In particular, fine perlitizing can alternatively or additionally be carried out by induction and / or flame. This can further increase the hardness, especially in a head area or on the running surface. Similarly, this process can be repeated after a certain period of use or operation in the field for reconditioning.

[0047] In comparison to the general state of the art, where the running surface is hardened exclusively by induction or flame, fine perlitization or bainitic treatment offers a number of advantages.

[0048] Among other things, the result of fine perlitization or bainiticization according to the invention is more reproducible with regard to material properties than with fine perlitation of the surface by induction or flame. In particular, subsequent changes in the carbon content in the area of ​​the later rail surface or running surface, as well as in the microstructure, are avoided. This contributes to a longer service life of the core component.

[0049] It can preferably be provided that the core, in particular in a head area or on the running surface, has a Brinell hardness between 200 HBW and 500 HBW and / or a tensile strength between 680 N / mm² at the end of the manufacturing process.2 and 1600 N / mm 2 exhibits.

[0050] This can be achieved in a particularly advantageous way by fine perlitizing or bainiticizing.

[0051] Preferably, the core component is forged or manufactured from steel. This steel may preferably conform to DIN standard EN 13674-1 (2017-07) or similar standards. For example, steel grades R200, R220, R260, R260Mn, R320Cr, R350HT, R350LHT, R370CrHT, or R400HT can be used as the material or starting material. R350HT is particularly preferred.

[0052] It can be particularly advantageous if the core is forged from C-Mn steel.

[0053] C-Mn steel is steel with carbon and manganese doping, or with a comparatively high carbon and manganese content. Preferably, a core piece forged from C-Mn steel can be normalized or finely pearlitized.

[0054] It can also be advantageous if the core is forged from Cr-Mo steel, preferably 35CrMo.

[0055] Cr-Mo steel is steel with Cr and Mo doping, or with a comparatively high chromium and molybdenum content.

[0056] 35CrMo can refer specifically to 35CrMo 11-3. The number 35 refers to the carbon content, while the further numbers 11 and 3 refer to the chromium and molybdenum content, respectively.

[0057] Preferably, a core forged from Cr-Mo steel, in particular 35CrMo or 35CrMo 11-3, can be bainiticized.

[0058] The choice between fine pearlitizing or bainitic finishing can depend in particular on the carbon content of the chosen steel.

[0059] Compared to cast iron frogs, steel frogs generally have a higher load-bearing capacity and lifespan or durability.

[0060] Preferably, the core can be manufactured with a length of at least 80 cm, preferably at least 1 m, in particular from 1 m to 5 m, preferably from 1 m to 4 m, further preferably from 1.5 m to 3 m, even more preferably from 2 m to 3 m, particularly preferably from 2.5 m to 3 m.

[0061] The length is the total length of the frog. The specified preferred length values ​​include, in particular, the frog tip, as well as the "connecting piece" or connecting element so designated in the prior art, which, according to the invention, is formed integrally with the rest of the frog, in particular the frog tip, and is not separate.

[0062] It has proven advantageous to provide a plurality of fastening elements on two opposite longitudinal sides of the frog, preferably 1 to 7, in particular 5 fastening elements per longitudinal side, which are forged in one piece with the frog in the die.

[0063] The fastening elements can serve, in particular, to fasten the frog to railway sleepers and / or to connect it to wing rails, especially by means of conventional sleeper screws, clamps, and angle guide plates. In a further development of the invention, the frog can be forged in one piece together with at least one, preferably two, wing rails in a die.

[0064] This reduces the subsequent effort required to connect the frog to the wing rails, for example, using screws or bolts. Furthermore, the one-piece design allows for simultaneous machining, enabling the frog and wing rails to be manufactured to tighter tolerances. Additionally, the one-piece design can result in a further increase in load-bearing capacity and thus service life.

[0065] In a preferred embodiment of the method, at least the following steps are provided for die forging:

[0066] - If necessary, heating of semi-finished steel products;

[0067] - If necessary, forming a preform from the steel semi-finished product;

[0068] Heating of semi-finished steel products or, if necessary, heating or reheating of the preform;

[0069] Inserting the semi-finished product or preform into a die with an upper die and a lower die, which together form a negative mold of the core to be produced;

[0070] Pressure forming of the semi-finished product or preform into a core piece by pressing the upper die and the lower die together;

[0071] - Optional removal of burrs on the core; and

[0072] - Tempering and / or heat-treating the core, in particular by normalizing, wherein the resulting normalizing heat is preferably used for fine perlitizing or bainiticizing.

[0073] This leads directly to at least the following two variants. Firstly, the procedure can be carried out with the following steps:

[0074] Heating of semi-finished steel products;

[0075] Inserting the semi-finished product into a die with an upper die and a lower die, which together form a negative mold of the core to be manufactured;

[0076] Pressure forming of the semi-finished product into a core piece by pressing the upper die and the lower die together;

[0077] - Optional removal of burrs on the core; and

[0078] - Tempering and / or heat-treating the core, in particular by normalizing, wherein the resulting normalizing heat is preferably used for fine perlitizing or bainiticizing.

[0079] This variant can be particularly suitable if the semi-finished product already has a shape that matches the die. Alternatively, the process can be carried out using the following steps:

[0080] - If necessary, heating of semi-finished steel products;

[0081] Forming a preform from the steel semi-finished product; - If necessary, heating or reheating the preform;

[0082] Inserting the preform into a die with an upper die and a lower die, which together form a negative mold of the core to be produced;

[0083] Pressure forming of the preform into a core piece by pressing the upper die and the lower die together;

[0084] - Optional removal of burrs on the core; and

[0085] - Tempering and / or heat-treating the core, in particular by normalizing, wherein the resulting normalizing heat is preferably used for fine perlitizing or bainiticizing.

[0086] However, the method according to the invention is not limited to the two variants listed above.

[0087] Preferably, the steps can be carried out in the order given. Further steps and / or sub-steps may be provided.

[0088] Semi-finished products generally refer to raw materials or pre-products. The material is preferably steel. Examples of semi-finished products include profiles or structural steel, slabs, billets, bars, tubes, and plates.

[0089] It is preferable to form the semi-finished product into a preform that resembles the shape of the core to be manufactured. The semi-finished product may be preheated for this purpose. The preform or forged blank is preferably slightly larger in all dimensions than the core to be manufactured. This procedure serves to limit the excess material during pressure forming and thus ensure effective forming of the core in the die. Creating a preform from the semi-finished product can be omitted, in particular, if the semi-finished product is already in a shape that fits the die.

[0090] Preferably, the material is heated at least once, i.e., before and / or after the optional forming of the preform from the semi-finished product. In other words, the material, regardless of whether it is in the form of a semi-finished product or a preform, is preferably heated at least once before being placed in the die and subjected to pressure forming.

[0091] The semi-finished product or preform can preferably be heated or reheated to a temperature above the recrystallization temperature of the material before or for pressure forming or die forming. However, the forming process can also be carried out at lower temperatures.

[0092] If necessary, the semi-finished product or preform is held at the desired temperature for a certain period of time. The die or mold contains at least a partial negative of the shape of the core part to be produced. A flash gap may be provided between the upper and lower dies. It may also be designed so that the upper and lower dies completely enclose the workpiece being manufactured when closed.

[0093] The upper and lower dies are movable relative to each other. Preferably, both the upper and lower dies are movable, and in particular, they are movable towards each other. Alternatively, the upper die can be lowered, while the lower die can remain stationary. It has proven advantageous if the semi-finished product or preform is placed on the lower die during insertion.

[0094] The die can preferably be operated mechanically, for example by an eccentric press, a forging hammer, a counter-hammer, a screw press or a hydraulic press, to press the upper and lower dies together. Within the scope of the invention, "pressing together" can be understood as either squeezing or a hammering motion.

[0095] If necessary, any burrs present on the frog may be removed before further processing. This can be done in particular by deburring and / or drilling.

[0096] Normalizing, also known as normalizing or refining, involves austenitizing at least the austenitizing temperature followed by cooling. Cooling can be carried out in still air or ambient air, or in a liquid bath.

[0097] In addition to changing the microstructure itself, as described elsewhere, normalization can also reduce irregularities in the microstructure in order to achieve a uniform microstructure with reproducible properties, especially grain sizes.

[0098] For perlitizing or fine perlitizing, it may be particularly possible to accelerate the cooling of the core after austenitizing the material, so that a pearlitic, especially fine-pearlitic, structure is produced.

[0099] For bainitic transformation, the isothermal conversion to the banite stage, it may be particularly possible to accelerate the cooling or quenching of the core after austenitizing the material to a temperature above the martensite start temperature and then to hold it there for a certain time, so that a bainitic microstructure is produced.

[0100] To control the cooling rate or cooling curve, i.e., the time-dependent temperature change, a preferably temperature-controlled liquid bath can be used. The core can, for example, be immersed in a salt water bath. Alternatively, immersion of the core in an oil bath, preferably an oil bath containing tempering oil, has proven suitable. This offers potential cost savings.

[0101] Temperatures and cooling rates should be selected to suit the desired microstructure. During bainitic treatment, the cooling values ​​should lie specifically between those for the formation of pearlite and martensite.

[0102] It has been shown that it is advantageous to rework the frog after die forging, in particular to rework a head area of ​​the frog to form a running surface for rail vehicles.

[0103] For example, the head area can be reshaped and / or smoothed.

[0104] The tread should be designed and shaped to be suitable for the wheels of the respective rail vehicles or train wheels. Rail vehicles could include, for example, locomotives or trains.

[0105] It may preferably be provided that the core is at least partially machined after die forging, preferably by milling and / or drilling.

[0106] Other methods and / or further processing steps may be required for post-processing.

[0107] The invention also relates to a frog for railway switches and / or rail crossings having a wedge-shaped frog point, wherein it is provided that the frog is manufactured by means of die forging, preferably by a method according to the invention as described above, and is formed in one piece, wherein two connecting surfaces are formed on one end face of the frog opposite the frog point in order to attach a connecting rail directly to each of them.

[0108] The method according to the invention is particularly suitable for producing a core component according to the invention. However, the core component according to the invention can also be produced in another way.

[0109] The core component according to the invention is characterized, due to its manufacture by die forging, by increased strength compared to casting processes, while maintaining the same or even lower weight. This results, among other things, in increased load-bearing capacity and service life of the core component. The one-piece or monolithic design of the core component according to the invention, and in particular the elimination of welds within the core component, also increases its load-bearing capacity and service life.

[0110] These and other advantages of the core component according to the invention result analogously from the advantages of the method according to the invention already described.

[0111] A particularly suitable embodiment has proven to be one in which the core is made of steel, preferably C-Mn steel or Cr-Mo steel, which further preferably has a microstructure with at least partial pearlite and / or bainite structure.

[0112] If the core is made of steel, preferably C-Mn steel or Cr-Mo steel, further preferably with a pearlite and / or bainite structure, a comparatively high load-bearing capacity and service life of the core can be ensured.

[0113] It can be advantageous if the core has a length of at least 80 cm, preferably at least 1 m, in particular from 1 m to 5 m, preferably from 1 m to 4 m, more preferably from 1.5 m to 3 m, even more preferably from 2 m to 3 m, and most preferably from 2.5 m to 3 m.

[0114] Preferably, the frog has a plurality of fastening elements on two opposite longitudinal sides of the frog, the fastening elements preferably being formed integrally with the rest of the frog.

[0115] Preferably 1 to 7, more preferably 3 to 7, particularly preferably 4 to 6, and especially exactly 5, fastening elements are provided on each longitudinal side.

[0116] The fastening elements are preferably designed and configured such that the frog can be fastened to railway sleepers, in particular by means of conventional sleeper screws, clamps, and angle guide plates. For this purpose, the fastening elements may preferably have upward-facing projections.

[0117] Furthermore, the fastening elements are preferably designed and configured such that the core can be connected to the wing rails by friction and / or positive locking. For this purpose, the fastening elements may have holes, which are preferably open to the side.

[0118] It has proven advantageous if the frog has at least one, preferably two, wing rails formed integrally with the frog. In a particularly preferred embodiment, the integral frog consists at least of the frog point, a connecting element having the connecting surfaces, the fastening elements, and / or the wing rails. The frog point, the connecting element with the connecting surfaces, the fastening elements, and / or the wing rails are therefore preferably formed as a single monolithic workpiece.

[0119] Further embodiments of the core element according to the invention result analogously from the method according to the invention.

[0120] Features described in connection with one of the subject matter of the invention, in particular those provided by the inventive method for manufacturing a frog or the inventive frog for railway switches and / or railway crossings, can also be advantageously implemented for the other subject matter of the invention. Likewise, advantages mentioned in connection with one of the subject matter of the invention can also be understood to relate to the other subject matter of the invention.

[0121] It should also be noted that terms such as "comprehensive," "exhibiting," or "with" do not exclude other characteristics or steps. Furthermore, terms such as "a" or "the," which indicate a singular number of steps or characteristics, do not exclude a plurality of characteristics or steps—and vice versa.

[0122] In a purist embodiment of the invention, however, it may also be provided that the features introduced in the invention with the terms "comprising," "comprising," or "with" are exhaustively listed. Accordingly, one or more lists of features within the scope of the invention may be considered complete, for example, for each claim. The invention may, for instance, consist exclusively of the features mentioned in claim 1.

[0123] It should be noted that designations such as "first" or "second" etc. are primarily used for the purpose of distinguishing between the respective device or process features and are not necessarily intended to indicate that features are mutually dependent or related to each other.

[0124] Exemplary embodiments of the invention are described in more detail below with reference to the drawing.

[0125] The figures each show preferred embodiments in which individual features of the present invention are combined with one another. Features of an embodiment can also be implemented independently of the other features of the same embodiment and can therefore be readily combined by a person skilled in the art to form further meaningful combinations and subcombinations with features of other embodiments. In the figures, functionally identical elements are provided with the same reference numerals.

[0126] The figures represent the invention only as an example and in a highly schematic way.

[0127] They show:

[0128] Figure 1 shows a schematic view from above of an embodiment of a core element according to the invention;

[0129] Figure 2 shows a general view of Figure 1 from the side;

[0130] Figure 3 is a basic perspective view based on Figures 1 and 2;

[0131] Figure 4 shows a basic perspective view based on Figures 1, 2 and 3 after post-processing of the core piece;

[0132] Figure 5 shows a schematic view from above of a further embodiment of the frog according to the invention with wing rails; and

[0133] Figure 6 shows a schematic view of a track section with a rail switch and a frog located therein.

[0134] Figures 1 to 5, described below, show various embodiments of a core element 1 according to the invention. The core element 1 is preferably manufactured using a method according to the invention. Figures 1 to 5 thus serve to disclose both the core element 1 and the method according to the invention.

[0135] In the inventive method for manufacturing a frog 1 for railway switches and / or railway crossings, which has a wedge-shaped frog point 2, the frog 1 is forged in one piece in a die, wherein two connecting surfaces 4 are formed on one end face 3 of the frog 1 opposite the frog point 2 in order to attach a connecting rail 5 directly to each of them.

[0136] The frog 1 according to the invention for railway switches and / or rail crossings, comprising a wedge-shaped frog point 2, is manufactured by die forging, preferably by a method according to the inventive process as described above and below, and is formed in one piece, wherein two connecting surfaces 4 are formed on one end face 3 of the frog 1 opposite the frog point 2, in order to attach a connecting rail 5 directly to each of them. It may be provided that the frog 1 is made of steel, preferably C-Mn steel or Cr-Mo steel, which further preferably has a microstructure with at least partial pearlite and / or bainite structure.

[0137] Accordingly, the frog 1 can preferably be forged from C-Mn steel according to the manufacturing process, wherein it is further preferably provided that the frog 1 is normalized or finely pearlitized. The frog 1 can also be forged from Cr-Mo steel, preferably 35CrMo, even more preferably 35CrMo 11-3, wherein in this variant it is preferably provided that the frog 1 is bainiticized.

[0138] It may be particularly suitable if the core 1 has a length of at least 80 cm, preferably at least 1 m, in particular from 1 m to 5 m, preferably from 1 m to 4 m, further preferably from 1.5 m to 3 m, even more preferably from 2 m to 3 m, particularly preferably from 2.5 m to 3 m, or if the core 1 is manufactured with such a length.

[0139] It should be noted that the frog point 2 preferably does not extend over the entire length of the frog 1. Preferably, the frog point 2 terminates in particular before an end of the frog 1 facing away from the connecting surfaces 4.

[0140] The manufacturing process may preferably include at least the following steps for die forging:

[0141] If necessary, heating of semi-finished steel products;

[0142] If necessary, form a preform from the steel semi-finished product;

[0143] Heating of semi-finished steel products or, if necessary, heating or reheating of the preform;

[0144] Inserting the semi-finished product or preform into a die with an upper die and a lower die, which together form a negative mold of the core to be produced;

[0145] Pressure forming of the semi-finished product or preform into a core 1 by pressing the upper die and the lower die together;

[0146] - Optional removal of burrs on the core; and

[0147] - Tempering and / or heat-treating the core 1, in particular by normalizing, wherein the normalizing heat generated is preferably used for fine perlitizing or bainiticizing.

[0148] The material, whether in its original semi-finished form and / or as a preform, is preferably heated at least once before being placed in the die and subjected to pressure forming. This can occur before and / or after the optional forming of the preform from the semi-finished product.

[0149] The process, as well as the semi-finished product, the preform or forged blank and the die with the upper and lower dies, are not shown in detail in the figures. Figure 1 shows a basic top view of a particularly advantageous embodiment of the core element 1 according to the invention.

[0150] In this embodiment, the frog 1 and the wedge-shaped frog tip 2 of the frog 1 each taper to a point when viewed from above. In particular, two longitudinal sides 8 of the frog 1 and two obliquely angled side surfaces 9 of the frog tip 2 converge towards each other, so that the longitudinal sides 8 and the side surfaces 9, respectively, form an acute angle when viewed from above.

[0151] Furthermore, the side surfaces 9 of the frog point 2 of the exemplary embodiment slope upwards towards each other in an imaginary cross-section. In other words, the frog point 2 widens in cross-section from top to bottom. An upper longitudinal edge 10 of the frog point 2 may be slightly rounded or flattened.

[0152] On each of the two opposite longitudinal sides 8 of the frog 1, fastening elements 11 (1 to 7, preferably 3 to 7, more preferably 4 to 6, and in particular exactly 5) can be provided to fasten the frog 1 to rail sleepers 12 and / or to connect it to wing rails 6, for example by means of conventional sleeper screws, clamps and angle guide plates. For this purpose, the fastening elements 11 can preferably have upwardly projecting projections 13 and / or holes 18, which are more clearly visible in Figures 2 and 3, which are described in more detail below.

[0153] For an illustration of an exemplary use of a frog 1 within a track section with a rail switch 14, reference is made to Figure 6, which is described in more detail below.

[0154] Figure 2 shows a basic side view based on Figure 1.

[0155] A front tip 15 of the frog point 2 can preferably be concavely rounded when viewed from the side in order to guide the wheels of rail vehicles running onto it as gently and with as little vibration as possible onto the frog 1 and the connecting rails 5 adjoining it.

[0156] The frog 1 can have two levels when viewed from the side, as can be seen in Figure 2. The frog point 2 is essentially located in an upper level 16a. The frog 1 can optionally project beyond the front tip of the frog point 2 on a lower level 16b. This results in a projection 17, which can serve, for example, for the stable support of the frog 1 in the track bed and / or for the secure fastening of the frog 1. The projection 17 is located, in particular, lower than the front tip 15 of the frog point 2.

[0157] Figure 3 shows a general perspective view according to Figures 1 and 2. Among other things, the projections 13 of the lateral fastening elements 11 for fastening the frog 1 to railway sleepers 12, for example by means of conventional sleeper screws, clamping clamps and angle guide plates, are particularly visible in this view.

[0158] Figure 4 shows a general perspective view according to Figures 1, 2, and 3 after post-processing of the frog 1, which is preferably carried out after die forging and heat treatment during manufacturing. In particular, a head region 7 of the frog 1 can be post-processed to form a running surface for rail vehicles or train wheels. Preferably, the post-processing of the frog 1 is carried out at least partially by machining, preferably by milling and / or drilling.

[0159] In comparison to Figure 3, a reshaping of the head area 7 towards the end face 3 of the frog 1 is particularly evident, in order to ensure the smoothest possible transition between the running surface of the frog 1 and the running surface of the connecting rails 5 attached to it during intended use. Furthermore, laterally open holes 18 have been added to the fastening elements 11 for the force-fit and / or form-fit connection of the frog 1 to wing rails 6, for example by means of screws or bolts.

[0160] Figure 5 shows a schematic top view of a further embodiment of the frog 1 according to the invention, comprising two wing rails 6 formed integrally with the frog 1. For this purpose, the frog 1 can preferably be die-forged together with at least one, preferably two, wing rails 6, analogous to the above description.

[0161] The core 1 is thus formed in one piece with at least one, preferably both, wing rails 6.

[0162] The embodiment of the frog 1 according to Figure 5, unlike that of Figures 1 to 4, does not have fastening elements 11 with projections 13. Instead, the frog 1 according to Figure 5 has a substantially flat base surface which, among other things, connects the frog point 2 and the wing rails 6 and forms a projection 17. The base surface can optionally be provided with holes for fastening to rail sleepers 12 (not shown).

[0163] Aspects not described in detail with regard to Figures 2 to 5 are analogous to Figure 1.

[0164] The embodiments of the frog 1 shown in Figures 1 to 4 and Figure 5 can be combined in any way. Furthermore, many other embodiments with differing features are conceivable. The embodiments shown are not to be understood as limiting. Figure 6 shows a schematic view of a track section with a rail switch 14 and a frog 1 arranged therein. This can be, in particular, a frog 1 as already described above with reference to Figures 1 to 5.

[0165] Figure 6 serves to illustrate a preferred use of the frog 1 according to the invention, or the frog 1 manufactured according to the invention, for a railway switch 14. Similarly, the frog 1, possibly with appropriate modifications to its design, can also be used for a railway crossing. This is not shown in the drawing.

[0166] The rail switch 14 typically comprises at least the frog 1, two wing rails 6, two switch blades 19, and two guide rails 20, wherein the frog 1 may preferably be formed integrally with the wing rails 6, analogous to Figure 5. The general operating principle of rail switches 14 is known to those skilled in the art and will not be explained in detail here.

[0167] The aforementioned components of the rail switch 14, like rails in general, are fastened in the track bed on rail sleepers 12 oriented transversely to the direction of travel or rail.

[0168] In the exemplary embodiment, the illustrated rail switch 14 divides a track into two tracks or merges two tracks into one, depending on the intended direction of travel. Connecting rails 5 are attached to the rail switch 14 on both sides, downwards and upwards in Figure 6, and in particular to the frog 1. A rail vehicle (not shown) traveling from bottom to top in Figure 6 would be directed onto the upper right track when the switch blades 19 are in the depicted position.

[0169] The use of the present invention is not limited to the embodiment shown in Figure 6. List of reference numerals:

[0170] 1 Centerpiece

[0171] 2 Heart tip

[0172] 3 Front side (of core 1)

[0173] 4 Connection area

[0174] 5 connection rail

[0175] 6 wing rail

[0176] 7 Head area (of the core 1)

[0177] 8 Long side (of the core 1)

[0178] 9 Side surface (of the core tip 2)

[0179] 10 Upper longitudinal edge (of the core tip 2) 11 Fastening element

[0180] 12 rail sleepers

[0181] 13 Overhang

[0182] 14 rail switch

[0183] 15 Front tip (of the core tip 2) 16a Upper level

[0184] 16b Lower Level

[0185] 17 lead

[0186] 18 holes

[0187] 19 Switch tongue

[0188] 20 Wheel guide rail

Claims

Patent claims 1. Method for manufacturing a frog (1) for railway switches and / or railway crossings comprising a wedge-shaped frog point (2), characterized by the fact that The frog (1) is forged in one piece in a die, wherein two connecting surfaces (4) are formed on one end face (3) of the frog (1) opposite the frog tip (2) in order to attach a connecting rail (5) directly to each of them.

2. Method according to claim 1 , characterized by the fact that the core (1) is normalized.

3. Method according to claim 1 or 2, characterized by the fact that the core (1) is finely pearlitized.

4. Method according to claim 1, 2 or 3, characterized by the fact that the center (1) is bainiticized.

5. Method according to any one of claims 1 to 4, preferably according to claim 3, characterized in that the core (1) is forged from C-Mn steel.

6. Method according to any one of claims 1 to 5, preferably according to claim 4, characterized in that the core (1) is forged from Cr-Mo steel, preferably 35CrMo.

7. Method according to any one of claims 1 to 6, characterized by the fact that the core (1) is manufactured with a length of at least 80 cm, preferably at least 1 m, in particular from 1 m to 5 m, preferably from 1 m to 4 m, further preferably from 1.5 m to 3 m, even more preferably from 2 m to 3 m, particularly preferably from 2.5 m to 3 m.

8. Method according to any one of claims 1 to 7, characterized by the fact that the core (1) together with at least one, preferably two, wing rails (6) is forged in one piece in a die.

9. Method according to any one of claims 1 to 8, characterized by the fact that The following steps are at least required for drop forging: If necessary, heating of semi-finished steel products; If necessary, form a preform from the steel semi-finished product; Heating of steel semi-finished products or, if necessary, heating or reheating of the preform; placing the semi-finished product or preform into a die with an upper die and a lower die, which together form a negative mold of the core to be produced; pressure forming of the semi-finished product or preform into a core (1) by pressing the upper die and the lower die together; Optional removal of burrs on the core; and - Tempering and / or heat-treating the core (1), in particular by normalizing, wherein the normalizing heat generated is preferably used for fine perlitizing or bainiticizing.

10. Method according to any one of claims 1 to 9, characterized by the fact that the frog (1) is reworked after die forging, in particular a head area (7) of the frog (1) is reworked to form a running surface for rail vehicles.

11. Method according to claim 10, characterized by the fact that the core (1) is at least partially machined after drop forging, preferably by milling and / or drilling.

12. Frog (1) for railway switches and / or railway crossings having a wedge-shaped frog point (2), characterized by the fact that the core (1) is manufactured by die forging, preferably by a method according to one of claims 1 to 11, and is formed in one piece, wherein two connecting surfaces (4) are formed on one end face (3) of the core (1) opposite the core tip (2) in order to attach a connecting rail (5) directly to each of them.

13. Core component (1) according to claim 12, characterized by the fact that The core (1) is made of steel, preferably C-Mn steel or Cr-Mo steel, which further preferably has a microstructure with at least partial pearlite and / or bainite structure.

14. Core (1) according to claim 12 or 13, characterized by the fact that the core (1) has a length of at least 80 cm, preferably at least 1 m, in particular from 1 m to 5 m, preferably from 1 m to 4 m, more preferably from 1.5 m to 3 m, even more preferably from 2 m to 3 m, particularly preferably from 2.5 m to 3 m.

15. Core (1) according to claim 12, 13 or 14, characterized by the fact that the center (1) has at least one, preferably two, wing rails (6) formed integrally with the center (1).

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