Current collector for a road vehicle, and road vehicle equipped with a current collector of this type

Abstract

The invention relates to a current collector (2) for a non-track-bound, electrically or hybrid-electrically driven road vehicle (1) for feeding electrical energy from a two-pole overhead line system having one contact wire (3, 3') per contact pole. The current collector comprises an articulated support linkage (4) which can be put upright and which supports two mutually spaced contact rockers (8). On each contact rocker (8), at least one contact strip (9) for contacting the contact wire (3, 3') assigned to the contact pole in question is resiliently mounted. A rocker bridge (12) which connects the contact rockers (8) is disposed and designed such that a contact wire (3') running between the contact bridges (8) is prevented from sagging below the contact strips (9) by lying on the rocker bridge (12). According to the invention, a contact wire sensor (22) for sensing a contact wire (3') lying on the rocker bridge (12) is designed to sense mechanical vibrations induced by a contact wire (3') lying on the rocker bridge (12).

Description

[0001] Description

[0002] Pantograph for a road vehicle and road vehicle equipped with such a pantograph

[0003] The invention relates to a current collector for a non-rail-bound, electrically or hybrid-electrically powered road vehicle according to the preamble of patent claim 1.

[0004] Such a pantograph is known from the published patent application DE 10 2018 215 593 A1. This pantograph is intended for a non-track-bound, electrically powered vehicle for feeding in electrical energy from a two-pole overhead line system with two contact wires. The fed-in energy is primarily used to directly supply traction to a vehicle drive, but can also be fed to an on-board energy storage device. The contact wires of the overhead line system are stretched above a carriageway usable by road vehicles, for example a lane of a multi-lane motorway. The pantograph comprises an articulated support rod which, on the contact wire side, carries two contact rockers with collector strips arranged next to one another and, on the vehicle side, has a base joint for linking to the vehicle.It further comprises a lifting drive coupled to the support rod for generating a torque in the base joint that lifts the contact rockers. This allows the contact rockers to be raised from a lower rest position to an upper contact position, so that their sliding strips are brought into electrical contact with the respective contact wire. To maintain the sliding contact that develops while the road vehicle is moving, the sliding strips are pressed against the contact wires with a predetermined pressure force by means of the lifting device.

[0005] Compared to rail traffic, where the rail vehicle is guided along the track and the pantograph must maintain contact with just one contact wire due to the single-pole overhead line system, it is much more difficult in road traffic to guide a road vehicle in such a way that contact between the contact strips and the contact wires is always maintained. In order to compensate for a certain tolerance in the contact wire positions and in the steering-related lane accuracy, the contact strips have a working area of ​​a certain width transverse to the longitudinal direction of the vehicle. This width is, however, limited by the mutual spacing of the contact wires in order to avoid a contact wire short circuit.For example, crosswinds, road topology, rolling movements of the road vehicle, inattention of the driver, as well as overtaking or evasive maneuvers can cause a contact wire to leave the working area of ​​a contact strip laterally or even to threaten to slip completely off the contact strip via the run-off horns provided for this purpose. Due to the pressure force exerted by the lifting device, there is a risk in such a case that a contact wire in the space between the contact rockers becomes caught under the.

[0006] The contact strips get caught and become caught, which could cause serious damage to the pantograph and overhead line system.

[0007] For this purpose, the pantograph known from DE 10 2018 215 593 A1 comprises a rocker bridge which connects the contact rockers and is designed as an immersion protection device and prevents a contact wire running laterally between the contact rockers from sinking below the contact strips. The rocker bridge is attached to the contact rockers and is shaped in such a way that, viewed in the longitudinal direction of the vehicle, the contact strips and rocker bridge form a continuous, smooth support curve for the contact wires. This means that lateral contact wire movement can be diverted into the rocker structures without any significant transverse forces. For safety reasons, however, it is still necessary to lower the pantograph in such a case. For this purpose, the rocker bridge of this known pantograph has two electrically conductive bridge brackets which are connected to a contact wire sensor for detecting contact between a contact wire and the bridge brackets.The contact wire sensor is designed as an electrical conductivity sensor that detects when a contact wire rests on both bridge brackets, thereby creating a conductive connection. The conductivity sensor can have a resistance circuit between the bridge brackets that is detuned when a low-resistance contact wire touches both bridge brackets. A resulting drop in voltage level is registered by a pantograph control system and can trigger a lowering of the support rods to dewire the pantograph.

[0008] A disadvantage of the current collector is that if the contact wire, which is designed as the positive pole, touches the overhead line, the high overhead line voltage can damage the pantograph control and other electronic components. Furthermore, especially in winter, there is a risk that the electrical conductivity of the contact wires is significantly reduced due to ice formation on their undersides, which can delay or even prevent detection of contact with the contact wire.

[0009] The invention is therefore based on the object of providing a current collector of the type mentioned at the outset which overcomes the disadvantages described.

[0010] The invention is based on a current collector for a non-rail-bound, electrically or hybrid-electrically powered road vehicle, for example for a heavy commercial vehicle. The current collector is provided for feeding in electrical energy from a two-pole overhead line system having a contact wire for each contact pole. The contact wires, designed as positive pole and negative pole, are preferably stretched centrally and parallel above a lane of a roadway that is thereby electrified, using infrastructure components known per se, such as masts, side supports, supporting cables, hangers, tensioning devices, and the like. The current collector comprises an erectable, articulated support rod that carries two contact rockers arranged at a distance from one another.The support rod can be designed like a pantograph and have a lower arm, an upper arm, a pull rod and a guide rod which are connected to one another by joints. By means of a lifting device on the pantograph, for example an air bellows, the support rod can be erected and the contact rockers can be raised. One of the contact rockers is assigned to each contact pole. At least one contact strip is spring-mounted on each of the contact rockers for contacting the contact wire assigned to the respective contact pole. Preferably, two contact strips are mounted on a contact rocker, arranged one behind the other in the longitudinal direction of the vehicle and parallel to a transverse direction of the vehicle. However, only a single contact strip can be mounted on each contact rocker. Downwardly curved run-off horns can be arranged on the lateral ends of the contact strips.The pantograph also comprises a contact bridge connecting the contact bridges, which is arranged and designed such that a contact wire running between the contact bridges is protected from sinking below the contact strips by resting on the contact bridge. This prevents a contact wire sliding towards the center of the vehicle from falling below a contact strip level and becoming caught there. To detect a contact wire resting on the contact bridge, the pantograph comprises a contact wire sensor.

[0011] According to the invention, the contact wire sensor is designed to record mechanical vibrations caused by a contact wire resting on the cantilever bridge. If, while the road vehicle is moving, a contact wire slides from a contact strip onto the cantilever bridge and rests on it in a sliding manner, or if a cantilever bridge strikes a contact wire when the current collector is being wired up, parts of the cantilever bridge or the entire cantilever bridge are set into vibration. The amplitudes and frequency patterns of such mechanical vibrations are characteristic of a given design of the cantilever bridge. By designing the contact wire sensor as a vibration sensor, this phenomenon can be used to detect the event of “detection of a contact wire resting on the cantilever bridge”. For this purpose, the recorded vibrations can be fed to an evaluation unit of the contact wire sensor and digitally evaluated there.For example, the currently recorded vibration patterns can be compared for similarity or agreement with vibration patterns provided in the evaluation unit that correspond to a detection event. Suitable vibration sensors include acceleration sensors, which usually determine the inertial force acting on a test mass. Depending on the setting, the acceleration sensor can briefly measure the amplitude and direction of acceleration experienced by a part of the rocker bridge connected to it, or it can continuously measure and record these accelerations over a predefined period of time. Acceleration sensors for road vehicles are tested and approved based on several measuring principles. This means that the problems of an electrical contact wire sensor described at the beginning, particularly with regard to susceptibility to errors due to weather or electromagnetic compatibility, can be avoided.Furthermore, the cabling, which is complex to install with the known contact wire sensor, is considerably simplified and the electrical insulation of the two bridge brackets of the rocker bridge can be omitted.

[0012] In an advantageous embodiment of the pantograph according to the invention, the contact wire sensor has a vibration sensor. The vibration sensor can, for example, piezoelectrically record vibrations of the part of the rocker bridge connected to it. A so-called seismic mass is preloaded in the vibration sensor, which strikes the piezoceramic due to the vibrations. Accelerations, speeds or regular vibrations can be measured. The measurable frequency range is between 0.2 and 20,000 Hz. The operating temperature is between -50 °C and +85 °C and is therefore well suited for road operation of the pantograph according to the invention. From a recorded accelerogram it can be concluded whether the rocker bridge moving in the direction of travel is vibrating due to a contact wire resting on it or whether the vibration pattern is not typical for this.

[0013] In a further advantageous embodiment of the current collector according to the invention, the contact wire sensor has a shock sensor. A shock sensor comprises electronic components that can change the initial state of their circuits due to shocks or vibrations that occur. This can be used to detect an impact of a contact wire on the rocker bridge, in particular if the current collector is incorrectly wired. Impacts and vibrations are continuously recorded using integrated MEMS (Micro Electro Mechanical System) technology. The evaluation unit integrated in the shock sensor differentiates between regular accelerations that occur when the current collector is raised and lowered and when the contact rockers deflect, and an impact event resulting from an impact of a contact wire on the rocker bridge.As soon as a preset limit is exceeded, an output signal is sent to a higher-level controller. The sensors can be attached directly to a component of the rocker bridge, for example, to one or both bridge brackets.

[0014] In a further advantageous embodiment of the pantograph according to the invention, the contact wire sensor has a microphone. The mechanical vibrations caused by the impact of a contact wire on the cantilever bridge and by the grinding of the cantilever bridge by a contact wire resting on it cause characteristic sound emissions from the vibrating parts of the cantilever bridge. A microphone with a suitable frequency range can record such sound events and, using an evaluation unit, monitor them for the presence of a detection event "detection of a contact wire resting on the cantilever bridge."

[0015] In a further advantageous embodiment, the current collector according to the invention further comprises a control device which is designed to trigger a lowering of the support rod with contact rockers, wherein the control device is connected to the contact wire sensor and triggers a lowering when the contact wire sensor has detected a contact wire resting on the rocker bridge. In order to avoid consequential damage after a contact wire has been rested on the rocker bridge, a rapid lowering of the current collector is triggered. This can be done, for example, by the dead weight of the support rod and the contact rockers, if the lifting device designed as an air bellows is deactivated and an air path with a large discharge cross-section is switched.

[0016] The invention also relates to an electrically or hybrid-electrically powered road vehicle with a current collector according to one of the preceding claims.

[0017] Further advantages and features of the invention will become apparent from the following description of an embodiment with reference to the drawings, in which

[0018] FIG 1 shows a current collector according to the invention, viewed in the longitudinal direction of the vehicle, and

[0019] FIG 2 is a perspective view of a rocker bridge of the pantograph from FIG 1. According to FIG 1 and FIG 2, an electrically or hybrid-electrically powered road vehicle 1, for example a truck or bus, comprises a pantograph 2, via which electrical energy can be fed in from an overhead line system even while the vehicle is in motion. The overhead line system is of two-pole design and comprises, stretched over a lane, a contact wire 3 for each contact pole to provide electrical energy. The pantograph 2 shown is designed as a half-scissor pantograph and comprises an articulated support rod 4 with a lower arm 5 and two upper arms 6, each of which is pivotally connected to the lower arm 5 via a knee joint 7.Each of the two upper arms 6 carries a contact rocker 8 on the contact wire side with two parallel collector strips 9 which are arranged one behind the other parallel to a vehicle transverse direction Y and with respect to a vehicle longitudinal direction X. In order to link the current collector 2 to the road vehicle 1, the lower arm 5 is pivotally connected to the road vehicle 1 on the vehicle side via a base joint 11 and is supported on a rod base 10. A lifting device which is known per se and is therefore not shown in detail is coupled to the support rod 5 in such a way that the contact rockers 8 can be raised. The lifting device can be designed as an air bellows which, when pressurized, generates a torque in the base joint 11 via suitable mechanical coupling means which lifts the contact rockers 8.

[0020] In a lower rest position of the contact rockers 8, the support rod 5 of the unwired pantograph 2 is folded together, so that the road vehicle 1 does not exceed the maximum permissible vehicle dimensions to be observed for operation outside electrified routes and the pantograph 2 is in an electrically secured state. When the pantograph 2 is wired, the lower arm 5 is straightened up, with pull rods (not shown) forcing the upper arms 7 to be straightened up until the contact rockers 8 have reached their upper contact position shown in FIG 1, in which electrical contact is established between the contact strips 9 and the contact wires 3. For this to happen, the road vehicle 1 must be sufficiently central in the electrified lane so that the contact points of the contact wires 3 lie within a working range of the contact strips 9.

[0021] The pantograph 2 comprises a rocker bridge 12 which is designed as an immersion protection for a contact wire 3' running laterally between the adjacent contact rockers 8. A contact wire 3 can get into the position of the contact wire 3' indicated in FIG 1 both when the pantograph 2 is being wired up and when the pantograph 2 is still wired up, if the vehicle 1 and thus the pantograph 2 are steered too far laterally from the center of the electrified lane. The rocker bridge 12 prevents the contact rockers 8 from rising due to the lifting force of the contact rockers 8 imparted by the lifting drive and thus prevents the contact wire 3' from penetrating the space between the contact rockers 8, which could otherwise lead to serious damage to the pantograph 2 and other components of the overhead line system.The rocker bridge 12 is fastened to the contact rockers 8 in order to achieve mutual alignment of the contact rockers 8 when a contact wire 3' is pressed against the rocker bridge 12. The rocker bridge 12 is shaped and arranged in such a way that, viewed in the vehicle's longitudinal direction X, the contact strips 9 and the rocker bridge 12 form a continuous, smooth support curve 13 for the contact wires 3 and 3' respectively. This results in a smooth transfer of a contact wire 3' between the adjacent contact rockers 8 without the movements of the contact rockers 8 being influenced by the rocker bridge 12 during normal operation.

[0022] 2, the rocker bridge 12 has two bridge brackets 14 which run parallel to the vehicle transverse direction Y and are arranged one behind the other with respect to the vehicle longitudinal direction X. The tubular bridge brackets 14 are curved and slope downwards at the sides. Approximately in the middle, the bridge brackets 14 are connected by a rod-shaped longitudinal control arm 16 via clamp elements 17 which engage around the bridge brackets 14 from below. Each clamp element 17 is coupled to one end of the longitudinal control arm 16 via a pivot joint 18 with a vertical axis of rotation. The rocker bridge 12 also has support elements 19, via which the bridge brackets 14 are supported on the adjacent contact rockers 8. The end sections 15 of the bridge brackets 14 are mounted in ball joints 20 which are arranged in the support elements 19. Thin-shafted ends of the bridge brackets 14 are guided longitudinally displaceably by the ball joints 20 .Due to its articulated connections and degrees of freedom of movement, the rocker bridge 12 allows relative movements of the contact rockers 8 and ensures their mutual alignment. Each of the two contact rockers 8 has two sliding strips 9 arranged one behind the other in the vehicle's longitudinal direction X, at the lateral ends of which downwardly bent discharge horns 21 are arranged, of which only the inner discharge horns 21 are visible in FIG. 2.

[0023] 1 and 2, the current collector 2 further comprises a contact wire sensor 22 which detects when the vehicle 1 with the current collector 2 wired on deviates from the track center to such an extent that a contact wire 3' has left the working range of a contact strip 9 and is resting on the bridge brackets 14 of the rocker bridge 12. According to the invention, the contact wire sensor 22 is designed to record mechanical vibrations which are excited by a contact wire 3' resting on the rocker bridge 12. If, while the road vehicle 1 is traveling, a contact wire 3' slides from a contact strip 9 onto the rocker bridge 12 and rests on it in a sliding manner, or if a rocker bridge 12 strikes a contact wire 3' when the current collector 2 is being wired on, parts of the rocker bridge 12 or the entire rocker bridge 12 are set into vibration.Amplitudes and frequency patterns of such mechanical vibrations are characteristic of a given design of the cantilever bridge 12. By designing the contact wire sensor 22 as a vibration sensor, this phenomenon can be used to detect the event “detection of a contact wire 3' resting on the cantilever bridge 12”. For this purpose, the recorded vibrations can be fed to an evaluation unit of the contact wire sensor 22 and digitally evaluated there. For example, the currently recorded vibration patterns can be compared for similarity or agreement with vibration patterns provided in the evaluation unit that correspond to a detection event. Suitable vibration sensors include, for example, acceleration sensors that determine the inertial force acting on a test mass.Depending on the setting, the acceleration sensor can briefly measure the acceleration in terms of amplitude and direction experienced by a part of the rocker bridge 12 connected to it, or it can continuously measure and record these accelerations over a predefined period of time.

[0024] The contact wire sensor 22 can also have a vibration sensor which, for example, piezoelectrically records vibrations of the part of the rocker bridge 12 connected to it. A so-called seismic mass is prestressed in the vibration sensor and strikes the piezoceramic due to the vibrations. Accelerations, speeds or regular vibrations can be measured. The measurable frequency range is between 0.2 and 20,000 Hz. The operating temperature is between -50 ° C and + 85 ° C and is therefore suitable for road operation of the pantograph 2 according to the invention. From a recorded accelerogram it can be concluded whether the rocker bridge 12 moving in the direction of travel is vibrating due to a contact wire 3' resting on it or whether the vibration pattern is not typical for this.

[0025] The contact wire sensor 22 can also have a shock sensor. A shock sensor comprises electronic components that can change the initial state of their circuits due to shocks or vibrations that occur. This can be used to detect an impact of a contact wire 3' on the rocker bridge 12, in particular when the current collector 2 is incorrectly wired. Impacts and vibrations are continuously recorded using integrated MEMS technology (Micro Electro Mechanical System). The evaluation unit integrated in the shock sensor differentiates between regular accelerations that occur when the current collector 2 is raised and lowered and when the contact rockers 8 deflect, and an impact event resulting from an impact of a contact wire 3' on the rocker bridge 12. As soon as a preset limit is exceeded, an output signal is sent to a control device 23 of the current collector 2.The sensors can be attached directly to a component of the rocker bridge 12, for example to one or both bridge brackets 14.

[0026] The contact wire sensor 22 may also include a microphone. The mechanical vibrations caused by the impact of a contact wire 3' on the cantilever bridge 12 and by the grinding of the cantilever bridge 12 by a contact wire 3' resting thereon cause characteristic sound emissions from the vibrating parts of the cantilever bridge 12. A microphone with a suitable frequency range can record such sound events and, by means of an evaluation unit, monitor for the presence of a detection event "detection of a contact wire 3' resting on the cantilever bridge 12".

[0027] In any case, a control device 23 of the pantograph 2 is designed to trigger a lowering of the support rod 4 with contact rockers 8, wherein the control device 23 is connected to the contact wire sensor 22 and triggers a lowering when the contact wire sensor 22 has detected a contact wire 3' lying on the rocker bridge 12. In order to avoid consequential damage after a contact wire 3' has been placed on it and / or after a grinding piece has broken, despite the rocker bridge 12, a rapid lowering of the pantograph 2 is triggered. This can be done, for example, by the dead weight of the support rod 4 and the contact rockers 8, driven by gravity, when the lifting device designed as an air bellows is deactivated and an air path with a large discharge cross-section is opened.

Claims

Patent claims 1. Current collector (2) for a non-track-bound, electrically or hybrid-electrically powered road vehicle (1) for supplying electrical energy from a two-pole overhead contact line system having a contact wire (3, 3') for each contact pole, comprising - a steerable, articulated support rod (4) which carries two contact rockers (8) spaced apart from each other, wherein at least one contact strip (9) for contacting the contact wire (3, 3') assigned to the respective contact pole is spring-mounted on each contact rocker (8), - a rocker bridge (12) connecting the contact rockers (8), which is arranged and designed such that a contact wire (3') running between the contact bridges (8) is protected from sinking below the contact strips (9) by resting on the rocker bridge (12), and - a contact wire sensor (22) for detecting a contact wire (3') resting on the rocker bridge (12), characterized in that the contact wire sensor (22) is designed to detect mechanical vibrations excited by a contact wire (3') resting on the rocker bridge (12).

2. Current collector (2) according to claim 1, - wherein the contact wire sensor (22) has a vibration sensor .

3. Current collector (2) according to any of the preceding claims, - wherein the contact wire sensor (22) has a shock sensor.

4. Current collector (2) according to any of the preceding claims, - wherein the contact wire sensor (22) has a microphone.

5. Current collector (2) according to any of the preceding claims, - furthermore comprising a control device (23) which is designed to trigger a lowering of the support linkage (4) with contact rockers (8), - wherein the control device (23) is connected to the contact wire sensor (22) and triggers a lowering when the The contact wire sensor (22) has detected a contact wire (3') resting on the rocker bridge (12).

6. Electrically or hybrid-electrically powered road vehicle (1) with a pantograph (2) according to one of the preceding claims.

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