This application claims priority to Patent Application No. EP 15305964.7 filed on Jun. 23, 2015, the disclosure of which including the specification, the drawings, and the claims is hereby incorporated by reference in its entirety.
The present invention concerns a railway bogie with a winterproof impact guard.
A railway bogie holds various kinds of operative components such as electrical and mechanical wiring and fluid piping, and many of them are exposed. Therefore, such equipment is likely to be damaged by chunks of ice, small stones, small animals etc. In particular, the wires and pipes under a railway bogie are easily damaged in winter or in a cold region due to the chunks of ice and accumulation of ice and snow. Accordingly, when railway vehicles operate under wintery conditions, their bogies must be winterised to prevent the bogie equipment from being damaged.
Conventionally, the applicant has used bent stainless steel sheets as winterproof impact guards for the bogies of its multiple units sold under the name Alstom Coradia Nordic. The steel sheets have high strength and are thereby suitable as impact guards. In addition, the steel sheets can be bent to appropriately cover otherwise exposed equipment under a railway bogie.
However, this known steel sheet solution is not very satisfactory. Indeed, upon impact, the steel sheets are prone to plastic deformation. Accordingly, they need to be replaced frequently. In addition, when a steel sheet is strongly deformed, it often damages or destroys the wires and pipes behind, which it is supposed to protect. That is to say, it is sometimes even necessary to replace not only the distorted steel sheet but also the wires, pipes and hoses after a collision. Due to the high stiffness of the folded steel sheets, the supporting secondary structure may also be damaged, which then needs to be repaired as well. Moreover, a metal fatigue fracture of the steel sheet may occur at its bend.
Therefore, it is an object of the present invention to provide a railway bogie with an improved impact guard for protecting bogie components such as wires and pipes under wintery conditions.
This object is achieved with a railway bogie comprising:
By using HDPE as the material for the impact guard, the affinity between snow or ice and the impact guard surfaces is reduced. Also, HDPE has a lower thermal conductivity than steel. Thus, there is less ice and snow accumulation on the impact guard. Furthermore, thanks to the good elasticity of the high density polyethylene (HDPE), the impact guard returns to its original shape after impacts of ice, snow, small stones and the like. Therefore, the damage in the secondary structure can be minimized. Overall, the invention reduces the costs for repairing damaged impact guards and damaged equipment such as wires, pipes and hoses.
The applicant surprisingly found out that HDPE can be successfully used in the construction of railway bogies. So far, bogie manufacturers always have refused to use plastics for railway bogies because of the purported inadequate properties of plastic compared to metal, and in particular steel.
According to other advantageous aspects of the invention, the railway bogie comprises one or more of the following features taken alone or according to all technically possible combinations:
The invention also relates to a diesel or electric multiple unit comprising at least one railway bogie as defined above.
The invention will be better understood when reading the following description, which is given solely by way of example and with reference to the appended drawings, in which:
The inventive impact guards are made of a particular plastic (synthetic resin). The plastic used for the impact guards must not become brittle and remain pliable at wintery temperatures, i.e. temperatures down to −50° C. The plastic must also have high impact strength and a low strain at yield stress. On top of that, the plastic must have low ice and snow adhesion. As a result of extensive testing, the applicant has found out that high density polyethylene (HDPE) meets these requirements. HDPE is therefore the material of choice for the impact guards according to the invention. Ultra-High-Molecular-Weight polyethylene (UHMW-PE or PE 1000) is a HDPE that is particularly well suited for making the inventive impact guards. The most preferred material for the impact guards is newly manufactured PE1000. However, reprocessed or recycled PE1000, sometimes referred to as PE1000R, may also be used. Preferably, black is chosen as the colour for the HDPE since black provides good protection against deterioration through ultraviolet (UV) radiation.
As shown in
The impact guard 1 includes a base 3 and at least one stiffening ridge 4 extending at a substantially right angle from the periphery P of the base 3. In
The impact guards 1, 5 and 6 of
The bogie frame 8 has two longitudinal side beams 9 and two transverse end beams 10 extending between the side beams 9. When the bogie frame 8 is in operation in a moving train, the end beams 10 are typically areas of air turbulence and thus snow accumulation in case of wintery conditions, and the end beams 10 are frequently hit by debris flying off the railway track. The end beams 10 and the operative components attached thereto are protected from these environmental stresses by several inventive impact guards 1a to 1e and 5a to 5d. The impact guards 1a to 1e are of the type shown in
More generally, the impact guards need only protect areas of the bogie that are exposed to flying debris, snow, ice or other risks. For example, in the case of a traction bogie, the parts close to the engine and gears do not normally need to be covered by the inventive impact guards since they are usually quite hot and located in the upper parts of the bogie.
The enlarged fragmentary bogie frame side view of
A conventional bogie with impact guards made of steel can be easily equipped with the improved impact guards of the present invention. Indeed, the holders and fastening means of the steel impact guards can be reused for fastening the new plastic impact guards to the bogie. This is done with the following procedure:
1. Take away the old steel impact guards, screws, washers and nuts. 2. Clean the impact guard receiving areas from rough dirt. 3. Install the new HDPE impact guards on the existing holders using the removed screws, washers and nuts. 4. Apply a lubricant such as Molykote® on the screws. 5. Tighten the screws until the washers slightly grab into the HDPE.
Number | Date | Country | Kind |
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15305964 | Jun 2015 | EP | regional |
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European Search Report dated Jan. 4, 2016 in corresponding EP application No. 15305964.7. |
Number | Date | Country | |
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20160375914 A1 | Dec 2016 | US |