Contact rail arrangement and charging method

Abstract

The invention relates to a contact rail arrangement 1 of a charging device for transmitting electrical energy to a current-carrying conductor of a vehicle, comprising a contact rail carrier 2 on which a contact rail 3 is arranged, wherein at least one electrical heating element 14 of a contact rail heater is arranged between the contact rail carrier 2 and the contact rail 3.

Description

The invention relates to a contact rail arrangement having the features of claim 1 and to a charging method according to claim 11.Electrically driven vehicles, such as buses, can be stationary, i.e. can be charged when stationary, by a displaceable contact rail of a charging device being brought up to vehicle-side electrical conductors in particular from above at a charging station. A weathering-related icing of the charging station and in particular of the contact rail can make charging more difficult or even impossible.The invention is based on the object of demonstrating a contact rail arrangement of a charging device which can be used reliably even at lower temperatures, in particular in the case of ice-forming weathering. A suitable charging method is to be shown which uses such a contact rail arrangement.The invention achieves this object by a contact rail arrangement having the features of patent claims 1 and 10, respectively.The contact rail arrangement according to the invention comprises a contact rail carrier on which a contact rail for making contact with a vehicle-side current-carrying conductor is arranged. The contact rail is a wear part. The contact rail arrangement is designed such that the contact rail can be exchanged regularly. This is therefore a releasable connection between the contact rail carrier and the contact rail.According to the invention, at least one electrical heating element of a contact rail heater is arranged between the contact rail carrier and the contact rail. The electric heating element is heated via its own heating circuit. The contact rail heater therefore includes a power source which is connected to the heating element and a corresponding control for the power source. The heating element is in contact with the contact rail and serves to keep the contact rail free of ice to ensure that ice adhering does not lead to interruption of electrical contact with a vehicle-side current-carrying conductor.The at least one heating element is advantageously designed as a heating film. In particular, only a single heating element and thus also only a single heating film is provided. A heating film has the advantage that it is particularly light and only insignificantly increases the weight of the contact rail arrangement. Heating foils are very thin and only a few millimeters thick, and generally thinner than 3 mm. They can be self-adhesive. They are bendable and can easily be adapted to bent contact rails in their course.The heating foil is arranged to be in contact with the contact rail, so that the heat emitted from the heating element as a heat source is directly introduced into the contact rail and prevents ice formation on the contact rail. It is important here that there is contact over as large a surface area as possible between the heating foil and the contact rail. The larger the contact surface between the heating surface and the contact rail, the more readily heating foils with lower heating power can be used.In order to produce the tight and as full-surface contact as possible, the heating element or the heating foil can preferably be arranged in the region of a contact surface of the contact rail carrier for the contact rail. In a first embodiment of the invention, a depression is formed in an abutment surface of the contact rail carrier, in which depression the at least one heating element is arranged. The heating element or the heating foil can protrude slightly beyond the contact surface, so that it is pressed firmly against the contact rail during the assembly of the contact rail. The contact rail thus bears as flat as possible against the heating element or the heating film. The depression can also be used to install thicker or more powerful heating elements or heating foils or else more pressure-sensitive heating elements. The contact surface or the encircling edge region outside the depression serves as a contact surface between the contact rail carrier and the contact rail. In all embodiments, an insulator for thermal insulation of the at least one heating element can be arranged on the contact rail carrier, so that the heat is transferred to the contact rail and not to the contact rail carrier. An insulator may be disposed in the recess. The contact rail carrier may itself be made of a thermally insulating material.The heating element can alternatively be held clampingly between the contact surface and the contact rail without a depression in the contact rail carrier. In this case, the contact rail does not bear directly on the contact surface, but rather on the heating element. This type of fastening has the advantage that the heating element or the film is held extremely securely and firmly and at the same time is in intimate contact with the contact rail, so that particularly good heat transfer is ensured.The effect of the heating element is maximized if the heat flow can be introduced into the contact rail over the largest possible surface. Therefore, the heating element should extend over at least 90% of the length of the contact rail, preferably over the entire length of the contact rail. In the same way, the heating element should extend over at least 50% of the width measured transversely to the length of the contact rail, in particular over 70 to 80, preferably 100%, of the width of the contact rail, insofar as this is technically possible.For mounting the contact rail on the contact rail carrier, fastening elements are required, which are typically formed by screw bolts, which pass through the contact rail. Accordingly, in the case of large-area heating elements, it is expedient to provide openings for receiving fastening elements, by means of which openings the contact rail is fastened to the contact rail carrier. If the fastening elements, in particular screws, also pass through the openings in the heating elements, they also fix the heating elements, so that they are always held on the contact rail arrangement such that they are captive and correctly positioned. In addition, the heating elements are always protected from damage and external influences because of their arrangement between the contact rail and the contact rail carrier.Depending on the configuration of the contact rail carrier, the contact rail can protrude with a narrow side opposite the contact rail carrier. The contact with the current-carrying conductor then takes place over the protruding region of the narrow side. Such a contact rail usually has an essentially rectangular cross section. The maximum heat input can be effected via the broad side, which preferably faces the front side of the contact rail carrier. Accordingly, the at least one heating element, in particular a heating film, is arranged between the front side of the contact rail carrier and the broad side of the contact rail. Due to this arrangement, the heating foil cannot be damaged even when the wear limit of the contact rail has been reached.In a further development of the invention, the contact surface against which the contact rail abuts can spring back with respect to the front side of the contact rail carrier to such an extent that a pocket is formed in which the contact rail is arranged. In this way, lighter and more compact contact rail supports can be used. The recessed contact surface again increases the protection of the at least one heating element against external influences, since the heating element itself is likewise arranged in the pocket. If a narrow side of the contact rail protrudes with respect to the contact rail carrier, this is preferably an arrangement in which the contact surface runs vertically. The contact surface of the contact rail with an electrical conductor is perpendicular to the contact surface and accordingly extends horizontally transversely to the direction of travel of the vehicle.In an alternative embodiment of the invention, the contact surface itself extends horizontally, wherein the contact rail is arranged adjacent in the vertical direction. The advantages described above also apply to this embodiment in the transferred sense. The planar heating element, preferably a heating foil, is located in a horizontal orientation between the contact rail and the contact rail carrier. In the same way, such a heating element can also have openings for receiving fastening elements. In the case of horizontal contact surfaces as well, the heating elements should extend over the largest possible surface of the contact rail, i.e. over preferably at least 90% of the length and at least 50%, preferably 80% of the width, wherein the heating element should assume as much as possible the same surface as the contact rail in order to maximize the surface for the heat transfer.The charging method according to the invention is based on the use of the contact rail arrangement described above. The stationary charging device has the said contact rail arrangement for transmitting electrical energy to a current-carrying conductor of a vehicle. The lading device is in particular a lowering unit, such as a pantograph, which is lowered from above in the direction of roof-side current-carrying conductors of a vehicle and thereby brings the contact rail arrangement into electrically conductive contact with the vehicle in order to charge its energy store. Even before charging, it is ensured that charging is not hindered by ice formation by the electrical heating element of the contact rail heater heating the contact rail before the contact is made. The heating may be initiated by a temperature sensor that measures the ambient temperature. Once the temperature falls below freezing, a controller may cause the contact rail to be heated. The heating can be time-controlled or approach-controlled, i.e. when a vehicle approaches or announces for charging, or movement-controlled, e.g. when the contact rail is displaced or else takes place at regular intervals or at specific times of day. It is also possible that by means of a visual detection of the icing or an ice load monitoring taking into account the weight, optionally in conjunction with weather data and / or with the aid of empirical values or with the aid of an AI, an adaptive adaptation of the switch-on times and switch-on time takes place, so that the charging device is ready for use at the desired point in time of use. The manual switching on and off of the contact rail heating is likewise possible.The invention is explained in more detail below with reference to exemplary embodiments illustrated in schematic drawings. The following are shown: FIG. 1 is a perspective view of a contact rail arrangement; FIG. 2 shows the contact rail arrangement of FIG. 1 in a front view; FIG. 3 shows the contact rail arrangement of FIG. 1 and in a section along the line III-III in FIG. 2 ; FIGS. 4 to 6 show variants of a contact rail arrangement in a view corresponding to the section line III-III in FIG. 2 ; FIG. 7 shows a further embodiment of a contact rail arrangement in cross section.FIG. 1 shows a contact rail arrangement 1 of a charging device, not shown in detail, for charging an electrically driven vehicle. The charging device is designed to bring the contact rail arrangement 1 into electrically conductive contact with conductors on the vehicle. The contact rail arrangement 1 is mounted on the charging device in such a way that the current-carrying conductor on the vehicle side runs substantially perpendicularly to the contact rail arrangement 1.The contact rail arrangement 1 has a contact rail carrier 2 which is connected to the charging device, and a contact rail 3 which is provided for contact with the current-carrying conductor on the vehicle side and is connected to the contact rail carrier 2 in a manner which is not shown in more detail, in particular is screwed via a plurality of screw elements. FIGS. 2 and 3 show the contact rail arrangement 1 in a front view and in section.The contact rail 3 is rectangular in cross section and has a narrow side 4 which projects downwardly beyond the contact rail carrier 2 in the plane of the drawing. The contact rail 3 is just as long as the contact rail carrier 2. the contact rail 3 is also located in a pocket 5, so that the contact rail 3 does not protrude beyond a front side 6 of the contact rail carrier 2. The contact rail 3 terminates at the front side with the front side 6 of the contact rail carrier 2. In an alternative embodiment, the contact rail 3 can protrude beyond the front side 6. The contact rail 3 has a front side 7 which is designed as a broad side. Opposite the front side 7 is the rear side 8 of the contact rail 3, which is arranged on a recessed contact surface 9 within the pocket 5. In the vertical direction, the contact rail 3 is supported with its upper narrow side 10 on a web 11 of the pocket. The pocket 5 is, to a certain extent, a notch or corner recess of the contact rail carrier 2, so that the pocket 5 is open toward the front side 6 of the contact rail carrier 2 and toward the lower side 12 thereof, which is situated at the bottom in the image side.FIGS. 4 to 6 show different embodiments of such contact rail arrangements 1 corresponding to the sectional plane III-III in FIG. 2, and in FIG. 4 there is additionally a depression 13 inside the contact surface 9. The term contact rail heating includes the means for controlling and supplying energy to the electric heating element. The electric heating element 14 can be switched on and off as required. More or less electrical energy can be supplied as required in order to set different heating powers depending on the weathering.FIG. 4 shows an exemplary embodiment in which the heating element 14 is protected to the maximum and is not exposed to any environmental influences.In an alternative embodiment according to FIG. 5, the depression 13 has been dispensed with. The heating element is held in a clamping manner between the rear side 8 of the contact rail and the contact surface 9. In a manner not shown in more detail, the respective heating element 14 extends substantially over the entire length of the contact rail 3 or the length of the contact rail holder 2.The exemplary embodiment of FIG. 6 differs from that of FIGS. 4 and 5 in that the design of a pocket within the contact rail carrier 2 has been dispensed with. As a result, the contact rail carrier 2 is substantially narrower overall and thus also lighter. The dimensions of the contact rail 3 have remained identical. The heating element 14 is also identical. It is again clampingly located between the rear side 8 of the contact rail and the contact surface 9, which in this case does not spring back but rather coincides with the front side 6 of the contact rail carrier 2.Whereas in the exemplary embodiments of FIGS. 1 to 6 the contact surface 9 is always oriented vertically, an alternative embodiment according to FIG. 7 provides that the contact rail carrier 2 is arranged horizontally at the top in the plane of the drawing with a horizontal contact surface 8, wherein the rear side 9 of the contact rail 3 is likewise arranged horizontally and is oriented parallel to the contact surface 8. The contact rail 3 has the same width and length as the contact rail carrier 2. Between the rear side 9 of the contact rail 3 and the contact surface 8 of the contact rail carrier 2 there is again a planar heating element 14, in particular in the form of a heating film. Functionally, this design corresponds to that of FIGS. 5 and 6, only the dimensioning of the contact rail 3 is a different one, and the fastening direction between the contact rail carrier 2 and the contact rail 3.Reference Number:1 Contact rail arrangement 2 Contact rail carrier 3 Contact rail 4 Narrow side of 3 5 Pocket in 2 6 Front side of 2 7 Front side of 3 8 Rear side of 3 9 Contact surface of 2 10 Upper narrow side of 3 11 Web 12 Underside of 2 13 Depression in 9 14 Heating element

Claims

Contact rail arrangement (1) of a charging device for transmitting electrical energy to a current-carrying conductor of a vehicle, having a contact rail carrier (2) on which a contact rail (3) is arranged, wherein at least one electrical heating element (14) of a contact rail heater is arranged between the contact rail carrier (2) and the contact rail (3).Contact rail arrangement (1) according to Claim 1, characterized in that the at least one heating element (14) is designed as a heating film which is in contact with the contact rail (3).Contact rail arrangement (1) according to Claim 1 or 2, characterized in that the contact rail carrier (2) has a contact surface (9) for the contact rail (3), wherein a depression (13), in which the at least one heating element (14) is arranged, is formed in the contact surface (9).Contact rail arrangement (1) according to Claim 1 or 2, characterized in that the contact rail carrier (2) has a contact surface (9) for the contact rail (3), wherein the at least one heating element (14) is held in a clamping manner between the contact surface (9) and the contact rail (3).Contact rail arrangement (1) according to one of Claims 1 to 4, characterized in that the at least one heating element (14) extends over at least 90% of the length of the contact rail (3).Contact rail arrangement (1) according to one of Claims 1 to 5, characterized in that the at least one heating element (14) extends over at least 50% of the width measured transversely with respect to the length of the contact rail (3).Contact rail arrangement (1) according to one of Claims 1 to 6, characterized in that the at least one heating element (14) has openings for receiving fastening elements, by means of which the contact rail (3) is fastened to the contact rail carrier (2).Contact rail arrangement (1) according to one of Claims 1 to 7, characterized in that the contact surface (9) jumps back with respect to a front side (6) of the contact rail carrier (2) to such an extent that a pocket (5) is formed in which the contact rail (3) is arranged.Contact rail arrangement (1) according to one of Claims 1 to 8, characterized in that the contact surface (9) runs vertically.Contact rail arrangement (1) according to one of Claims 1 to 8, characterized in that the contact surface (9) runs horizontally, the contact rail (3) being located adjacent to the contact rail carrier (2) in the vertical direction.Charging method using a contact rail arrangement (1) according to one of Claims 1 to 10 at a charging device for transmitting electrical energy to a current-carrying conductor of a vehicle, wherein the electrical heating element (14) of the contact rail heater heats the contact rail (3) before the contact rail (3) is brought into contact, coming from above by the charging device, with a current-carrying conductor arranged on the roof side.

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