The invention relates to a device for fixing and positioning a rail monitoring element on a rail web of a rail. The rail web of the rail is arranged between a rail foot and a rail head of the rail. The invention further relates to the use of the device for fixing and positioning a rail monitoring element on a rail web of a rail.
A device for fixing a rail monitoring element is known from DE 10 2015 209 721 B3 [3].
To make rail traffic safer, rail monitoring elements, e.g. sensor elements for axle counters, are used. Axle counters can be used in particular to check whether the location of the axle counter has been fully passed by a train, for example to determine whether the associated track sections are free or occupied. Such rail monitoring elements comprise sensor elements which are usually fastened to the rail.
Fiber optic sensors are becoming increasingly important in rail monitoring. One or more sensors, such as fiber Bragg gratings (FBGs), embedded in optical waveguides are used to detect expansion or compression of the optical fiber caused by a mechanical variable, and thus to detect the forces, torques, accelerations, loads, pressure states, etc.
A rail monitoring element having FBG sensors is known from DE 10 2017 216 811 A1 [2], for example. [2] proposes that the rail monitoring element be adhesively fastened, i.e. adhesively bonded, to the rail. However, the rail monitoring element must be positioned and fixed at the mounting site in order to do this.
Mounting a sensor element of an axle counter on a rail by means of a clamping device is known from [3]. The device known from [3] is used to receive a sensor on/fasten a sensor to the rail web and is designed for this purpose. This device is not designed to absorb horizontal forces. Furthermore, this device is adapted to a specific rail foot. A mounting tool should fit a large number of different rail profiles, however. The device from [3] also requires a certain amount of space under the rail, which is not always available.
An L-shaped elastic clamp for fixing an inductive heating device by means of which a planar inductor can be held on the rail web of a rail is known from EP 3 169 138 A1 [1]. A first leg of the clamp engages around the rail foot from below. A second leg of the clamp exerts a lateral preload on the inductor such that said inductor is pressed against the rail web of the rail.
The problem addressed by the invention is that of providing a device which makes fixing and positioning a rail monitoring element on a rail web of a rail more efficient, simpler, and more precise. The invention also addresses the problem of specifying a use of such a device.
This problem is solved by a device for fixing and positioning a rail monitoring element according to the claims and a use of the device according to the claims. The dependent claims specify advantageous embodiments of the invention.
The device according to the invention has a clamping device by means of which the device can be fastened to the rail. The clamping device is preferably designed in such a way that it can be driven over by a rail vehicle. The device also has a pressing ram for pressing the rail monitoring element against the rail web, as well as a force element. When the device is in the mounted state, the pressing ram can be pressed against the rail web by means of a force generated by the force element. The device preferably further comprises a holder for receiving the force element. The force element is connected to the pressing ram and is designed to exert pressure thereon.
In the mounted state, the device for fixing and positioning the rail monitoring element is fixed to the rail via the clamping device thereof. The clamping device thereby forms a receptacle for a rail part. This can be the rail foot or the rail head, for example. The clamping device can be braced against the rail web. The clamping device can be set to different rail widths and rail profiles.
The design of the device according to the invention allows the force element to generate pressure on the pressing ram in the mounted state, for example when the rail monitoring element is to be fixed on the rail for an adhesive bonding process and positioned. The pressing ram in turn presses the rail monitoring element against the rail web. The rail monitoring element is preferably arranged in the receptacle of the pressing ram. In this state, the pressure on the rail monitoring element is maintained, for example until a potential adhesive bonding process has been completed.
In one embodiment of the invention, the clamping device is a rail foot clamp via which the device can be fastened to the rail foot of the rail. The advantage of a design as a rail foot clamp is that the clamp can still be driven over by a rail vehicle. The rail foot clamp comprises a foot portion which, in the mounted state, engages under the rail foot of the rail and forms a rail foot receptacle. If the rail monitoring element needs to be fixed and positioned above a sleeper of the rail structure, the rail foot clamp can be two-part. Two-part means that a first part of the rail foot clamp can be mounted on one side of the sleeper and a second part of the rail foot clamp can be mounted on the other side of the sleeper.
In another embodiment of the invention, the clamping device is a rail head clamp. The device can be fastened to the rail via the rail head clamp, the rail head clamp engaging over the rail head and gripping the rail web on both sides in the mounted state. As a rule, this embodiment cannot be driven over by a rail vehicle, but has the advantage that no free space under the rail is required. The rail head clamp preferably has clamping jaws which grip the rail web. These clamping jaws can have bevels which are adapted to the shape of the rail web. This ensures that the rail head clamp always grips the rail at the same height, specifically preferably at the desired height. The clamping jaws can have recesses and form a so-called “C-shape” in order to reduce material consumption and the weight of the clamp. Devices having rail head clamps can be used e.g. in subways or third rail systems.
The force element can be mounted on the same side of the rail as the pressing ram. In this embodiment, the force element exerts the force directly on the pressing ram.
In a further embodiment of the invention, the force element can be mounted on the side of the rail opposite the pressing ram. In this embodiment, the force element is designed to generate a pressure against the rail web by means of which the holder of the force element is pulled away from the rail. The side of the holder located on the opposite side of the rail is moved in the same way in the same direction, so that the pressing ram, which is located on the side of the rail opposite the force element, is pressed against the rail web. Depending on the environment where the rail monitoring element is to be mounted, this embodiment may be advantageous, e.g. if there is not enough space available on the side of the rail on which the rail monitoring element is to be mounted. However, it requires space on the side of the rail that is opposite the rail monitoring element.
The force element can be a pneumatic or hydraulic force element, i.e. a pneumatic cylinder or a hydraulic cylinder, for example. The pneumatic cylinder or the hydraulic cylinder preferably has a piston rod which is in operative connection with the pressing ram and is able to transmit the force generated by the force element to the pressing ram. The piston rod is preferably mechanically connected to the pressing ram.
In one embodiment of the invention, the pressing ram can be tilted relative to the at least one piston rod. The pressing ram can thus be moved relative to the axis of the pressure cylinder. This is intended to compensate for when the sensor element cannot be pressed toward the piston rod in a straight line and the plane against which the rail monitoring element is to be pressed is slightly inclined relative to the pressure direction of the piston rod instead.
In a preferred embodiment of the invention, the at least one piston rod is designed to be non-rotatable relative to the pressing ram. In this context, non-rotatable means that no unintentional rotation with an axis of rotation in the direction of the at least one piston rod can take place. This can be achieved, for example, by the at least one piston rod having an angular or oval cross section, by the piston rod being guided by means of a guide groove, or, for example, by two parallel piston rods being provided which transfer the pressing pressure to the pressing ram. Non-rotatability of this kind, which prevents rotation with an axis of rotation in the pressure direction of the at least one piston rod, has the advantage that it is possible to ensure that the rail monitoring element is applied to the rail in a straight line relative to the rail course.
In one embodiment of the invention, the stroke of the pneumatic cylinder or the hydraulic cylinder can be set. In this way, the device can be set to different requirements and rail geometries and/or different geometries of rail monitoring elements.
According to a preferred embodiment of the invention, a control unit is provided which displays and/or sets the pressure exerted on the pressing ram. It is also possible to limit the pressure by means of e.g. a pressure relief valve of which the trigger threshold can be permanently preset. If a pneumatic cylinder is used as a force element, the control unit can have a pressure gauge or interact with a pressure gauge, for example. The pressure exerted by the pneumatic cylinder can also be displayed via the pressure gauge.
In one embodiment of the invention, the pressing ram has a receptacle for the rail monitoring element, the pressing ram having the receptacle being designed in such a way that it can be pressed flat onto the rail web. Such a shape of the pressing ram is particularly advantageous for bringing about a reliable adhesive bonding process of the rail monitoring element to the rail, since flat pressing with a predetermined pressure is particularly advantageous for an adhesive bonding process.
In one embodiment of the invention, the holder is adjustable relative to the clamping device. The adjustment takes place in the mounted state perpendicularly to the underside of the rail, which allows the height at which the rail monitoring element is pressed against the rail to be set. This means that different rail dimensions and rail geometries can be covered.
In a preferred embodiment of the invention, the force element is designed as a magnet which generates a compressive force via an attractive force between the rail and the magnet. Magnets are arranged, for example, in the clamping jaws of an overhead clamp and preferably abut the rail web.
The device is particularly suitable for adhesively bonding a rail monitoring element to a rail web of a rail. The adhesive bonding process usually requires flat pressing with a predetermined pressure. Such an effect can ideally be achieved using the device according to the invention. Use of the device for adhesive bonding is therefore particularly advantageous.
Further advantages of the invention can be found in the descriptions and the drawings. Likewise, according to invention, the aforementioned features and those explained below can each be used individually or together in any desired combination. The embodiments shown and described should not be understood as an exhaustive list; rather, they describe the invention by way of example.
In the drawings:
In
In
The magnets 54 hold the entire device on the rail web 52. The pressure cylinder 20 cannot “push away” the device when it is actuated. The magnets 54 and the pressure cylinder 20 are therefore preferably matched to one another in such a way that the following applies: force generated by magnets>force generated by pressure cylinder 20. As a rule, the pressing force of the magnets 54 is greater than the pressing force of the pressure cylinder 20. Due to the greater pressing force, this embodiment is particularly suitable, for example, for fixing adhesive bonds in which the adhesive has to be heated.
Number | Date | Country | Kind |
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19192517.1 | Aug 2019 | EP | regional |
This continuation application claims priority to PCT/EP2020/072881 filed on Aug. 14, 2020 which has published as WO 2021/032627 A1 and also the European patent application number 19192517.1 filed Aug. 20, 2019, the entire contents of which are fully incorporated herein with these references.
Number | Date | Country | |
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Parent | PCT/EP2020/072881 | Aug 2020 | US |
Child | 17651411 | US |