POSITIONING UNIT AND METHOD FOR CONTACTING

Description

[0001] The invention relates to a positioning unit according to claim 1 and a method according to claim 8.

[0002] Such positioning units and methods are known from the prior art and are regularly used in electrically powered vehicles that travel between stops. These can be electric buses, but also, in principle, other vehicles, such as trains or trams, that are not permanently electrically connected to an overhead wire or similar structure. In these vehicles, an electrical energy storage device is recharged at a charging station when the journey is interrupted at a stop. The vehicle is electrically connected to the charging station at the stop, whereby the energy storage device is charged at least sufficiently for the vehicle to reach the next stop with a charging station.To establish an electrical connection between the vehicle and the charging station, a positioning unit is used, which can be mounted on the vehicle roof or alternatively above the vehicle, for example on a mast. The positioning unit can then connect a charging contact to a charging contact surface, so that the vehicle or the energy storage device can be charged at the charging station.

[0003] A key aspect of merging a charging contact and a charging contact surface is that the charging contact is pressed onto the charging contact surface with a defined contact force to establish a reliable electrical connection. A positioning unit positioned above a vehicle is known from DE 202014007218 U1, wherein the positioning unit comprises an articulated arm device and a drive device. The drive device includes an adjustment drive and a spring assembly, which serve to move the articulated arm device relative to the vehicle's charging contact surface. In particular, an upward movement of the articulated arm device requires an adjustment force from the adjustment drive.

[0004] A persistent disadvantage of known positioning units is that they must be designed or arranged for a defined contact height, meaning a specific distance between the positioning unit in its retracted position (for securing the charging contact) and the contact position for power transmission to the vehicle. This means that the relative distance between the contact position and the retracted position is not variable and must be regularly adjusted or modified through design changes, otherwise the necessary or desired contact force cannot be applied to the charging contact surface. Particularly when vehicle types and thus vehicle heights change, the relative distance between the retracted position and the contact position can fluctuate significantly due to differing heights of the vehicles' contact surfaces above the road surface.The same applies to uneven vehicle loads or lowering a vehicle or bus at a stop to facilitate access for people with disabilities, for example. When the vehicle is lowered, the charging contact moves vertically relative to the charging contact surface if the contact force can no longer be maintained.

[0005] Another disadvantage is that the extension of the charging contact is relatively slow. If a vehicle needs to be charged during a stop at a bus stop, the vehicle's stop time should be used as effectively as possible for charging. However, extending the charging contact as quickly as possible, and thus ensuring rapid contact between the charging contact surface and the charging contact, is not easily achievable, as the charging contact or the charging contact surface could then be damaged or wear out relatively quickly during the contacting process. Furthermore, the contact and charging contact surface coming into contact can generate an undesirable noise that could disturb or unsettle residents near the bus stop or passengers.

[0006] CN 101 531 141 A shows a positioning unit for establishing an electrically conductive connection between a stationary charging station and an electrically powered vehicle. The positioning unit comprises an articulated arm device for positioning a charging contact and a drive device for driving the articulated arm device. Furthermore, the drive device has a sensor device and a control device by means of which the position of the charging contacts can be detected and adjusted.

[0007] DE 10 2010 027670 A1, US 2013 / 076902 A1, WO 2009 / 039406 A1, WO 2015 / 126320 A1 and US 2014 / 0360832 A1 as well as GB 2 518 129 A concern further positioning units of the aforementioned type.

[0008] It is therefore an object of the invention to propose a positioning unit and a method for forming an electrically conductive connection between a vehicle and a charging station, which enables a safe contact with the vehicle during an extended charging time.

[0009] This problem is solved by a positioning unit having the features of claim 1 and a method having the features of claim 8.

[0010] The positioning unit according to the invention for forming an electrically conductive connection between a stationary charging station and a vehicle, in particular an electric bus or the like, is designed such that an electrical charging contact, which the positioning unit has, is movable relative to a charging contact surface and can be made contact with it by means of the positioning unit, wherein the positioning unit has an articulated arm device and a drive device for driving the articulated arm device, wherein the charging contact can be positioned by means of the articulated arm device between a contact position for current transmission and a retraction position for current interruption, wherein the drive device has an adjustment drive for generating an adjustment force acting on the articulated arm device, and wherein the drive device has a control device by means of which the adjustment drive can be controlled.wherein the drive device has a sensor device by means of which the charging contact surface can be detected, wherein the sensor device is coupled to the control device, wherein a speed of the charging contact during a movement of the charging contact from the insertion position to the contact position can be controlled as a function of a relative distance of the charging contact and the charging contact surface from the control device, wherein the drive device has a spring device that mechanically interacts with the adjustment drive, wherein the positioning unit comprises a holding device for attaching the positioning unit above a vehicle to a mast or underpass, wherein the spring device comprises at least one return spring for generating a return force on the articulated arm device, wherein the return force is greater than a weight force of the articulated arm device acting opposite to the return spring.

[0011] The positioning unit can therefore be part of a stationary charging station for an electric vehicle or part of an electric vehicle itself. Its function is to move the charging contact of the charging station or the vehicle onto a charging contact surface of the vehicle or the charging station and establish electrical contact with it. This allows the vehicle to be supplied with electrical energy during a break in driving at the charging station and for this energy to be stored in the vehicle. The movement of the charging contact to and from the charging contact surface is performed by the articulated arm and the drive mechanism of the positioning unit. The charging contact is located at one end of the articulated arm.The drive unit serves to move the charging contact, and thus the articulated arm assembly, from a retracted position for storing the charging contact to a contact position for current transfer, i.e., contacting the charging contact surface with the charging contact. The adjusting force is exerted on the articulated arm assembly by the drive unit's actuator. During movement of the charging contact, the adjusting force depends on the mechanics of the articulated arm assembly or the gear ratio of the actuator and therefore changes very little.

[0012] The drive unit also includes a control unit, which can, for example, be control electronics for the actuator. The control electronics can be integrated directly into the actuator, the vehicle, or the charging station. Furthermore, the drive unit's sensor unit can detect or measure the charging contact surface and determine its position. Since the sensor unit is coupled to the control unit, it is possible to determine or calculate the relative distance between the charging contact and the charging contact surface. It is essentially irrelevant whether the sensor unit is directly connected to the control unit via electrical wiring or whether the connection is wireless.By determining the relative distance, it becomes possible to regulate the speed of the charging contact during its movement from the retraction position to the contact position, depending on the relative distance between the charging contact and the charging contact surface. This allows for an almost arbitrarily high speed initially, as long as the charging contact is sufficiently slow in the final phase of its movement from the retraction position to the contact position to prevent damage to the charging contact or the charging contact surface and / or undesirably high noise emissions during the contacting process. This regulation of the extension movement, or speed, of the charging contact makes it possible to contact the charging contact surface comparatively faster, thus advantageously extending the charging time of a vehicle during a stopover at a bus stop.Simultaneously, noise generation during contact between the charging contact and the charging contact surface can be advantageously influenced. Optionally, the movement of the charging contact from the contact position to the retracted position can be controlled in a consistent manner by the control device.

[0013] The positioning drive can generate a contact force on the charging contact surface. The drive may include a control unit and an electric motor that can be controlled by the control unit. In the contact position, the positioning unit can thus generate a defined contact force on the charging contact surface. In the retracted position, however, no or only a very small adjustment force can act on the articulated arm device, so that no movement of the articulated arm device or the charging contact can occur. When the charging contact and the charging contact surface make contact, the adjustment force can be increased by the positioning drive, resulting in the generation or increase of the contact force on the charging contact surface.The control unit can, in particular, detect the torque of the electric motor via, for example, the energy input, and regulate the electric motor so that the defined contact force is generated by the electric motor, via the articulated arm device and the charging contact, onto the charging contact surface. It is then possible to actively adjust the direct force applied to the articulated arm device and, if applicable, to the charging contact, optionally also depending on various influencing factors. Thus, regardless of the relative distance between the charging contact surface and the positioning unit, or the vehicle height, a consistently high contact force can be generated on the charging contact surface.

[0014] If the positioning drive uses a brushless electric motor, a particularly high number of motion cycles can be performed. A brushless electric motor requires significantly less and longer maintenance intervals than a brushed electric motor with the same mechanical performance data. This makes it possible to design a positioning unit with extended maintenance intervals and a longer service life. For example, a three-phase asynchronous machine with a squirrel-cage rotor, a synchronous machine with electronic rotating field generation, or a brushless DC motor can be used as a brushless motor, or an electric motor without sliding contacts between the rotor and stator.

[0015] The adjustment drive can be a linear drive, preferably a spindle drive, and most preferably a self-locking spindle drive. The spindle drive can then have a corresponding spindle with a pitch that prevents self-locking. The linear drive can cause the articulated arm device to move from the retracted position to the contact position and vice versa. The spindle can, in particular, be a ball screw or a trapezoidal screw, which can be coupled to the electric motor.

[0016] The sensor device can include at least one sensor, which can be a mechanical switch, an inductive sensor, a capacitive sensor, a magnetic sensor, an ultrasonic sensor, a radar sensor, and / or an optical sensor. The sensor device can also optionally include several sensors of the same or different types. This ensures that in the event of a sensor failure or under varying environmental conditions, at least one sensor can detect the charging contact area. In a simple embodiment, the sensor can be a mechanical switch that contacts the charging contact area before the charging contact itself and is thus triggered. Inductive and capacitive proximity sensors are particularly advantageous when only a short switching distance is required. Larger switching distances can be achieved with a magnetic sensor.An ultrasonic sensor has a sufficient range and is relatively robust. A radar sensor can also measure the distance to the charging contact surface even if it is covered with a layer of dirt or snow. Optical sensors are particularly well-suited for distance measurement and are relatively independent of environmental conditions. An optical sensor can be designed using infrared light, lasers, or simple LEDs.

[0017] The sensor can be arranged on the articulated arm device, particularly adjacent to the charging contact. It is essential that the sensor is positioned so that it can detect the relative distance between the charging contact surface and the charging contact. The sensor can be arranged at a distal end of the articulated arm device near the charging contact. In a non-inventive embodiment of the positioning unit, the sensor can also be arranged on the charging contact surface, provided that the sensor can then detect the charging contact or the relative distance. The sensor arranged on the charging contact surface can then, for example, wirelessly transmit distance information to the control unit. This makes it possible to equip charging stations with corresponding sensors, even if the control unit is mounted on the vehicle, or vice versa.

[0018] The actuator and / or the articulated arm can be equipped with a displacement sensor and / or a position sensor. Using the displacement sensor allows for setting a range within which the articulated arm can be moved by the actuator. An incremental or absolute encoder, for example, can be used as the displacement sensor. This also makes it possible to always determine a precise working position of the actuator or the charging contact. The actuator can also have position-dependent limit switches and / or force-dependent pressure switches. Furthermore, the magnitude of the contact force can be limited by restricting the actuator's extension to a specific end position. Pressure switches can also be used to limit the contact force, either alone or in conjunction with the limit switches.A pressure switch can be located directly at the charging contact, or alternatively at the articulated arm or the adjustment drive. However, these sensors are not part of the sensor assembly and are therefore not suitable for directly determining the relative distance between the charging contact and the charging contact surface.

[0019] According to the invention, the drive device has a spring assembly that interacts mechanically with the adjustment drive. The spring assembly can have at least one tension spring or one compression spring that can exert a spring force on the articulated arm device. Preferably, a tension spring can be used, since a tension spring can be connected to the articulated arm device particularly easily. It is also possible for the spring assembly to have a plurality of springs, and for the spring force to act permanently on the articulated arm device. The spring can therefore be pre-tensioned in any position of the articulated arm device. Alternatively, it is also possible to use a compression spring to generate the spring force. Such a spring assembly is particularly robust and can be manufactured simply and cost-effectively.

[0020] A spring in the spring assembly can be mechanically coupled to the articulated arm assembly via a lever in the spring assembly's mechanism. The effective length of the lever can be variable depending on the position of the articulated arm assembly. The lever can therefore be directly attached to the articulated arm assembly, allowing the spring force to be directly transmitted to it. Depending on the position and direction of the spring force, and the lever's position on the articulated arm assembly, the effective length of the lever can be shortened if the angle between the direction of the spring force and the lever's extension is less than or greater than 90°. The effective length of the lever can also be varied by attaching the spring to a stop on the articulated arm assembly via a return mechanism, such as a cam or a pull rod.The cam disc then forms the lever of the return mechanism. Depending on the cam disc's position relative to the spring, the effective length of the lever can be influenced. This makes it possible to apply the same return force to the articulated arm regardless of its position, or to increase or decrease the return force as required depending on the articulated arm's position. The return force can also be adjusted to the adjustment force and the contact force. It is advantageous if the return force is dimensioned such that, in any position of the articulated arm, if the adjustment drive fails (for example, due to a power outage), the charging contact retracts automatically as a result of the return force. This ensures particularly reliable operation of the positioning unit.

[0021] According to the invention, the positioning unit comprises a mounting device for attaching the positioning unit to a mast or underpass above a vehicle. The spring assembly includes at least one return spring to generate a return force on the articulated arm device, wherein the return force is greater than the weight of the articulated arm device acting in the opposite direction to the return spring. The mounting frame can, for example, provide or have fixed bearings for the articulated arm device and the adjustment drive. In particular, the return spring or the adjustment drive can be directly attached to a fixed bearing on the mounting frame. The mounting frame can also be attached particularly easily to the mast or underpass, as well as to a canopy of a bus stop, a tunnel, or similar structures that a vehicle can pass under.Because the positioning unit can be located above a vehicle, the adjustment drive can be designed as a lowering drive for lowering the contact element and interact mechanically with the spring assembly or the return spring. After the charging contact surface makes contact with the charging contact, returning the charging contact to its retracted position at the positioning unit above the vehicle is easily accomplished if the spring assembly, at least with its one return spring, exerts a restoring force on the articulated arm assembly. Since this restoring force can then be greater than the opposing force of the articulated arm assembly's weight acting on the return spring, the articulated arm assembly can be moved from the contact position to the retracted position without the adjustment drive being active or receiving power.Even when the charging contact is in the retracted position, the restoring force counteracts the weight force and is preferably slightly greater than it to prevent the charging contact from sinking or extending when the articulated arm device is not subjected to any further force.

[0022] In a non-inventive embodiment, the positioning unit can include a mounting device for attaching the positioning unit to the roof of a vehicle. The spring assembly can include at least one lifting spring to generate a lifting force on the articulated arm assembly, whereby the lifting force can then be less than the weight force of the articulated arm assembly acting in the opposite direction to the lifting spring. The mounting frame can also form or have fixed bearings for the articulated arm assembly and the drive unit, but is then attached to the roof of the vehicle. The mounting frame can be easily installed on the roof using dampers, feet, and / or insulators. This also makes the positioning unit particularly easy to replace. When the positioning unit is attached to the roof of the vehicle, the adjustment drive can be a lifting drive for extending the charging contact, which can mechanically interact with the spring assembly.Here too, contact between the charging contact surface and the charging contact can be easily achieved by extending the charging contact into the contact position, provided the spring assembly includes at least the lifting spring to generate the lifting force that, together with the adjusting force of the actuator, acts on the articulated arm device. This lifting force can be less than the weight of the articulated arm device acting against the lifting spring. Thus, the weight of the articulated arm device and the charging contact arranged on it can cause the articulated arm device to move from the contact position to the retracted position without being initiated by the actuator. The lifting force opposing the weight is preferably slightly less than the weight to ensure that the charging contact retracts in the event of, for example, a power failure.However, the lifting force also supports the adjustment drive when it exerts the adjustment force on the articulated arm device during an extension of the articulated arm device, so that only a small adjustment force needs to be applied.

[0023] The articulated arm device can be designed as a single-arm system, a scissor system (preferably with a parallelogram linkage), or a pantograph. This allows the articulated arm system to enable parallel movement of the charging contact from its retracted position to its contact position on the charging contact surface. Damping elements can also be arranged on the articulated arm device to ensure smooth movement.

[0024] The drive unit can be designed to connect to a vehicle's data bus. For example, the adjustment drive can be controlled directly via the data bus. The sensor unit can also be connected to the data bus, allowing the control unit to be located anywhere in the vehicle.

[0025] In the inventive method for forming an electrically conductive connection between a stationary charging station on a vehicle, in particular an electric bus or the like, an electrical charging contact, which the positioning unit has, is moved relative to a charging contact surface by means of the positioning unit and contacted with it, wherein an articulated arm device of the positioning unit is driven by a drive device of the positioning unit, wherein the charging contact is positioned by means of the articulated arm device between a contact position for current transmission and a retraction position for current interruption, wherein an adjusting force is generated by means of a locking drive of the drive device which acts on the articulated arm device, and wherein the adjusting drive is controlled by means of a control device of the drive device.wherein a sensor device of the drive unit detects the charging contact surface, wherein the sensor device is coupled to the control device, wherein the speed of the charging contact during a movement of the charging contact from the retraction position to the contact position is controlled by the control device as a function of a relative distance between the charging contact and the charging contact surface, wherein a further sensor device of the drive unit detects the charging station or the vehicle, wherein the control device determines a relative distance of the charging contact in the retraction position and in the contact position, wherein the control device initiates the movement of the charging contact out of the retraction position before the vehicle stops at the charging station. For the advantageous effects relating to the method according to the invention, reference is made to the description of the advantages of the positioning unit according to the invention.

[0026] During its movement from the insertion position to the contact position, the charging contact can initially experience positive acceleration and later negative acceleration. The negative acceleration can then act on the charging contact, particularly after detection of the charging contact surface or the charging contact itself, at a predetermined relative distance between the charging contact and the contact surface.

[0027] During the movement of the charging contact from the retracted position to the contact position, the charging contact can be moved at a constant and / or maximum speed in a first phase of movement, and at a relatively reduced speed in a second phase before reaching the contact position. This means that the charging contact is initially extended as quickly as possible from the retracted position and then decelerated just before reaching the contact position, thus making contact with the charging contact surface. This controlled extension of the charging contact allows for faster contact between the charging contact and the charging contact surface than before, thereby advantageously extending the charging time. Furthermore, the charging contact can be decelerated or its speed reduced before reaching the charging contact surface so that contact between the charging contact and the charging contact surface occurs only relatively slowly.This reduces the likelihood of mechanical damage to the charging contact and contact surface, as well as wear and tear. Furthermore, it virtually eliminates any disruptive noise during contact.

[0028] The constant or maximum speed can be ≥ 100 mm per second, preferably ≥ 360 mm per second, particularly preferably ≥ 500 mm per second.

[0029] The reduced speed upon reaching the contact position can be at least 70%, preferably 50%, and particularly preferably 30% of the constant and / or maximum speed, or 0 mm per second. This ensures that the charging contact does not strike the charging contact surface at maximum speed. By determining the relative distance, the control device can also reduce the speed to such an extent that it is 0 mm per second upon reaching the contact position, or that the charging contact is stopped.

[0030] The speed can be reduced before reaching the contact position at a relative distance of ≤ 150 mm, preferably ≤ 100 mm, and particularly preferably ≤ 50 mm. This relative distance is still within the detection range of a wide variety of sensors and can therefore be easily determined by the sensor device. The charging contact can then also be moved at high speed over a large portion of its path towards the charging contact surface.

[0031] It is particularly advantageous if the speed can be reduced before reaching the contact position according to a linear or approximation function. The control device can include a control element that regulates this reduction in speed, for example, based on a signal from the sensor device when the relative distance through the charging contact falls below a defined threshold.

[0032] At least one sensor of the sensor system can continuously transmit a distance value or a defined threshold value of the relative distance to the control system. For example, the sensor can be configured to continuously transmit the relative distance or an actual value of the relative distance to the control system. Alternatively, the sensor can transmit a signal to the control system only once, if the previously defined relative distance is undershot. After receiving the signal, the control system can then reduce the speed of the charging contact.

[0033] The adjustment drive can exert a contact force on the charging contact surface, whereby an electric motor of the adjustment drive can be controlled by means of the control device.

[0034] The control device can detect the torque of the electric motor, and the contact force can be regulated by the control device depending on the torque of the electric motor.

[0035] The contact force can be generated independently of the relative distance between the charging contact surface or the contact position and the entry position of the positioning unit. This makes it possible to contact vehicles of different heights relative to a road surface with the positioning unit.

[0036] In the contact position, the contact force can remain constant even when the relative distance between the charging contact surface or the contact position and the insertion position of the positioning unit changes. A change in the relative distance of a vehicle to a road surface always results in a change in the relative distance between the contact position and the insertion position. This change in relative distance can be caused by lowering the vehicle via its suspension or by loading the vehicle. Because the contact force is relatively large compared to the adjustment force, it can remain essentially constant even when the relative distance changes. Maintaining a constant contact force, independent of the relative distance, is even simpler if the control unit regulates the contact force based on the torque of the electric motor.If the relative distance increases due to lowering the vehicle, the contact force decreases, and consequently, so does the torque of the electric motor. This torque is then increased again by the control unit, resulting in a constant contact force. Conversely, a reduction in the relative distance leads to an increase in the contact force and thus the torque, which the control unit can counteract by reducing the torque.

[0037] The control unit allows the torque of the electric motor to be adjusted depending on the position of the articulated arm or the actuator. This makes it possible to optimally adapt the direct force applied to the articulated arm and, if applicable, the contact element to the respective position of the articulated arm, thus ensuring that the force applied to the charging contact surface remains essentially constant regardless of the position of the articulated arm. For example, a position sensor can detect the position of the articulated arm, and the control unit can adjust the torque accordingly, eliminating the need for large torque jumps when regulating the contact force.

[0038] The control unit can also detect when the contact position is reached by means of a torque limit that is exceeded. In the contact position, the charging contact makes contact with the charging contact surface, which significantly increases the torque of the electric motor. This increase in torque can be detected by the control unit as the reaching of the contact position. For example, any existing speed control of the electric motor can then be deactivated, since only a fine-tuning of the electric motor's torque in the contact position is then necessary. Furthermore, in the contact position, the control unit can then, for example, send a release signal for energy transfer from a charging station. Therefore, no additional sensors are required to detect the contact position.

[0039] The control unit allows the electric motor's torque to be limited and maintained at a constant level once a target torque value is reached. Limiting the torque prevents the electric motor from being overloaded. Furthermore, it also ensures a constant contact force. The same applies to the extension and retraction speed of the charging contact, which can then be increased to a limited extent.

[0040] The control unit allows the target torque value to be regulated within a tolerance range of + / - 10%. This tolerance range is perfectly adequate for generating a substantially constant contact force, thus eliminating the need for particularly precise torque measurement of the electric motor by the control unit. This also makes the control unit more cost-effective to design.

[0041] The control device allows the electric motor to reach its maximum speed after a running time of 0 to 7 seconds, preferably 1 to 3 seconds. This prevents or reduces immediate force and vibrations in the adjustment drive and the articulated arm assembly. This controlled start-up of the electric motor also extends the service life of the positioning unit.

[0042] The control device can regulate the speed of the electric motor in such a way that the charging contact is moved at a constant speed, at least in certain sections. For example, it can be designed so that the charging contact is extended from its retracted position with an initial positive acceleration and retracted with a negative acceleration, but that a majority of the movement of the charging contact into the contact position occurs at a constant speed.

[0043] According to the invention, the charging station or the vehicle is detected by means of a further sensor device of the drive unit, wherein the control device determines a relative distance of the charging contact in the retracted position and in the contact position, wherein the control device initiates the movement of the charging contact from the retracted position before the vehicle stops at the charging station. Thus, a horizontal distance between the vehicle and the charging station can be determined by means of the further sensor device, whereby if a threshold value of the distance is undershot, the charging contact can be extended from the retracted position in a controlled manner, so that when the vehicle is under the charging station in the position intended for charging, the charging contact is already close to the charging contact surface, or vice versa. In this way, the charging time can be advantageously extended even further.Conversely, the charging station can also have the charging contact, and the vehicle the charging contact surface. The additional sensor device can also have at least one of the aforementioned sensors. If necessary, the additional sensor device can also be integrated into the sensor device.

[0044] The control unit can determine the relative height of the charging contact and / or the contact position above a vehicle, and can also determine the vehicle's height above a travel path. It is advantageous to know the vehicle's height above the travel path, especially since this height can vary significantly depending on the vehicle's load. The height can be determined, for example, via the vehicle's chassis or via sensors specifically designed for this purpose. From the vehicle's height above the travel path and the charging contact's position relative to the vehicle in the entry position, the control unit can calculate the charging contact's height relative to the travel path. If the height of the charging contact surface above the travel path is known, for example, in the case of a charging station, an exit speed or...The maximum speed of the charging contact when extending from the entry position can be regulated before the vehicle reaches the charging station.

[0045] Further advantageous embodiments of the method are set out in the dependent claims relating to device claim 1.

[0046] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

[0047] They show: Fig. 1 a first embodiment of a positioning unit in a retracted position in a side view; Fig. 2 the positioning unit in a contact position in the side view; Fig. 3 a second embodiment of a positioning unit in a contact position in a perspective view; Fig. 4 a detailed view from Fig. 3 ; Fig. 5 the positioning unit Fig. 3 in an entry position in a perspective view; Fig. 6 the positioning unit Fig. 3 in the contact position in a perspective view.

[0048] A summary of Fig. 1 und 2 Figure 1 shows a first embodiment of a positioning unit 10 in various positions. The contacting of a charging contact surface 11 is only symbolically illustrated here. The positioning unit 10 comprises an articulated arm device 12 and an adjustment drive 13 for driving the articulated arm device 12. The articulated arm device 12 is designed as a single-arm system 14 and comprises an upper scissor 15 with an upper scissor arm 16 and an upper coupling rod 17, as well as a lower scissor 18 with a lower scissor arm 19 and a lower coupling rod 20. An upper coupling element 21 is pivotably attached to the upper scissor arm 16, so that a holder 22 of the positioning unit 10 for an electrical charging contact (not shown) of the positioning unit 10 can always be moved parallel to a horizontal plane 23. For this purpose, the upper coupling element 21 is connected to the upper coupling rod 17 via an axis 38.The lower scissor arm 19 and the lower coupling rod 20 are each pivotably mounted on fixed bearings 24 and 25, respectively, of a support frame 26 of the positioning unit 10. The lower scissor arm 19 is pivotably connected to the upper scissor arm 16 via an axis 27. A pivoting movement of the upper scissor arm 16 consequently results in a parallel movement of the support frame 22 relative to the horizontal plane 23.

[0049] The adjustment drive 13 is designed as a linear drive 28. A spring assembly 29 of the positioning unit 10 is designed with a return spring 30, which is designed as a tension spring 31. The tension spring 31 is attached to a fixed bearing 32 on the mounting frame 26 and to an axle 33 of a lever 34. The lever 34, together with the axle 33 and the tension spring 31, forms a return mechanism 35. Depending on the position of the articulated arm device 12, the lever 34, which is rotationally fixed to the lower scissor arm 19, is pivoted relative to the tension spring 31, so that the effective length of the lever 34 is shortened or lengthened. In a retracted position 36 and in a contact position 37 of the positioning unit 10, the tension spring 31 acts directly on the axis 33. If the articulated arm device 12 is extended further downwards, the effective length of the lever 34 is significantly shortened by pivoting it.This makes it possible to adjust the tension spring 31, or rather its effective restoring force, to a position of the positioning unit 10. The articulated arm device 12, together with the adjustment drive 13, has a design-related weight force, including a charging contact (not shown), which acts on the charging contact or the holder 22. The tension spring 31 generates a spring force, or a restoring force, that exceeds the weight force, so that, regardless of the position of the positioning unit 10, even in the event of a power failure, the positioning unit 10 always returns to the retracted position 36.

[0050] A lever 39 is fixed to the articulated arm 12, or the lower scissor arm 19, and forms an actuating mechanism 40 for the articulated arm 12. The linear drive 28 is pivotally mounted on an axis 42 of the lever 39. The linear drive 28 is further fixedly connected to the mounting frame 26 via an axis 41. The linear drive 28 is driven by an electric motor 43 and is not self-locking. Thus, in the event of a power failure, for example, the tension spring 31 can automatically move the articulated arm 12 from the contact position 37 to the retracted position 36, thereby retracting the linear drive 28. The linear drive 28 therefore also serves to dampen movement of the articulated arm 12. Furthermore, the positioning unit 10 includes a control device, which is not shown in detail here, to which the electric motor 43 is connected.The control device detects the torque of the electric motor 43, and adjusts the torque of the electric motor 43 as a function of a contact force exerted by the charging contact (not shown) on the charging contact surface 11. The contact force is sufficiently high to establish an electrical contact and can be maintained at a substantially constant level in contact position 37 and in any other desired contact position by regulating the torque of the electric motor 43.

[0051] The actuator 13 or the electric motor 43 can be controlled by means of the control device (not shown here). A sensor 61 of a sensor device 62 is arranged on the holder 22 of the lower scissor arm 19, by means of which a relative distance between the sensor 61 and the plane 23 or charging contact surface 11 can be detected. Thus, a relative distance between the charging contact (not shown here) and the charging contact surface 11 can also be determined. Since the sensor device 62 is coupled to the control device, the speed of the charging contact during a movement of the charging contact from the retraction position 36 to the contact position 37 can be controlled by the control device as a function of a measured or detected relative distance between the charging contact and the charging contact surface 11.

[0052] A summary of Fig. 3 bis 6 Figure 1 shows a second embodiment of a positioning unit 44, which is mounted on the roof of an electrically powered vehicle (not shown). The positioning unit 44 essentially comprises an articulated arm 45, at the end of which 46 charging contacts 47 and 48 are arranged for contacting a charging contact surface (not shown in detail) located above the vehicle. The positioning unit 44 further comprises an adjustment drive 49, a spring assembly 50, and a mounting frame 51. The articulated arm 45 is designed as a single-arm system 52, similar to the single-arm system described above. The spring assembly 50 comprises two tension springs 53, which are designed as lifting springs 54 and exert a lifting force on the articulated arm 45.The lifting force is dimensioned such that the weight of the articulated arm device 45 together with the charging contacts 47 and 48 is greater than the lifting force, so that in the event of a power failure, for example, the articulated arm device 45 always lowers from a working position 55 or a contact position (not shown) to a retracted position 56. The adjustment drive 49 therefore comprises a non-self-locking linear drive 57 with an electric motor 58 which is connected to and controlled by a control unit (not shown) of the positioning unit 44. The control unit detects a torque of the electric motor 58 and regulates the torque of the electric motor 58 so that a defined contact force is generated at the charging contacts 47 and 48.The linear drive 57 comprises a trapezoidal threaded spindle (not shown here), which is housed in a casing 59 of the linear drive 57 and acts on a drive rod 60 via a nut. By moving the drive rod 60, the articulated arm device can thus be moved into the contact position or into the retracted position 56.

[0053] The positioning unit 44 also has a sensor 63 of a sensor device 64, wherein the sensor 63 is attached to the single-arm system 52 adjacent to the charging contacts 47. In particular in the Fig. 3The positioning unit 44, or the single-arm system 52, is shown in a working position 55. The working position 55 is located at a distance from a contact position 65 such that the charging contacts 47 and 48 are still at a relative distance A from a charging contact surface (not shown in detail here). The charging contact surface is indicated by a line 66, and the working position 55 by a line 67 arranged parallel to it. The charging contact surface is located within a detection range 68 of the sensor 63, so that the speed of the charging contacts 47 and 48 during a movement from the insertion position 56 to the contact position 65 can be controlled by the control device as a function of the relative distance A between the charging contacts 47 and 48 and the charging contact surface or line 66.

Claims

1. A positioning unit (10) for forming an electrically conductive connection between a stationary charging station and a vehicle, in particular an electric bus or similar, wherein an electrical charging contact of the positioning unit can be moved relative to a charging contact surface (11) and contacted with the same by means of the positioning unit, wherein the positioning unit has an articulated arm device (12) and a drive device for driving the articulated arm device, wherein the charging contact can be positioned between a contact position (37) for power transmission and a retracted position (36) for power interruption by means of the articulated arm device, wherein the drive device has an adjustment drive (13) for forming an adjustment force acting on the articulated arm device, wherein the drive device has a control device by means of which the adjustment drive can be actuated, wherein the drive device has a sensor device (62) by means of which the charging contact surface can be detected, wherein the sensor device is coupled with the control device, wherein a speed of the charging contact during movement of the charging contact from the retracted position into the contact position can be controlled by the control device in accordance with a relative distance (A) between the charging contact and the charging contact surface, wherein the drive device has a spring device (29) mechanically cooperating with the adjustment drive, wherein the positioning unit comprises a holding device (26) for fastening the positioning unit above a vehicle on a pole or an underpass, wherein the spring device has at least one restoring spring for forming a restoring force acting on the articulated arm device, wherein the restoring force is greater than a gravitational force of the articulated arm device acting on the restoring spring in the opposite direction.

2. The positioning unit of claim 1, characterized in that a contact force acting on the charging contact surface (11) can be formed by the adjustment drive (13), wherein the adjustment drive has the control device and an electric motor (43), which can be actuated by the control device.

3. The positioning unit of claims 1 or 2, characterized in that the adjustment drive (13) is a linear drive (28), preferably a spindle drive, particularly preferably a spindle drive without self-locking.

4. The positioning unit of any one of the preceding claims, characterized in that the sensor device has at least one sensor (61), the sensor being a mechanical switch, an inductive sensor, a capacitive sensor, a magnetic sensor, an ultrasonic sensor, a radar sensor and / or an optical sensor.

5. The positioning unit of claim 4, characterized in that the sensor (61) is disposed on the articulated arm device (12), in particular adjacent to the charging contact.

6. The positioning unit of any one of the preceding claims, characterized in that the adjustment drive (13) and / or the articulated arm device (12) has a displacement sensor and / or a position sensor.

7. The positioning unit of any one of the preceding claims, characterized in that the drive device is configured for coupling with a data bus of a vehicle.

8. A method for forming an electrically conductive connection between a stationary charging station and a vehicle, in particular an electric bus or similar, wherein an electrical charging contact (47, 48) of a positioning unit (10, 44) is moved relative to a charging contact surface (11) and contacted with the same by means of the positioning unit, wherein an articulated arm device (12, 45) of the positioning unit is driven by a drive device of the positioning unit, wherein the charging contact is positioned between a contact position (37, 65) for power transmission and a retracted position (36, 56) for power interruption by means of the articulated arm device, wherein an adjustment force acting on the articulated arm device is formed by means of an adjustment drive (13, 49) of the drive device and wherein the drive device of the adjustment drive is actuated by a control device, wherein a sensor device (62, 64) of the drive device detects the charging contact surface, wherein the sensor device is coupled with the control device, wherein a speed of the charging contact during movement of the charging contact from the retracted position into the contact position is controlled by the control device in accordance with a relative distance (A) between the charging contact and the charging contact surface, characterized in that another sensor device of the drive device detects the charging station or the vehicle, wherein the control device determines a relative distance of the charging contact in the retracted position and in the contact position, wherein the control device initiates the movement of the charging contact out of the retracted position before the vehicle stops at the charging station.

9. The method of claim 8, characterized in that during movement of the charging contact from the retracted position (36, 56) into the contact position, the charging contact (47, 48) is positively accelerated at first and negatively accelerated at a later point.

10. The method of claim 8 or 9, characterized in that during movement of the charging contact (47, 48) from the retracted position (36, 56) into the contact position (37, 65), the charging contact (47, 48) is moved at constant and / or maximum speed in a first movement section and is moved at a relatively reduced speed in a second movement section before reaching the contact position.

11. The method of claim 10, characterized in that the constant or maximum speed is ≥ 100 mm / s, preferably ≥ 360 mm / s, particularly preferably ≥ 500 mm / s.

12. The method of claim 10 or 11, characterized in that upon arrival in the contact position, the reduced speed is at least 70 %, preferably 50 %, particularly preferably 30 % of the constant and / or maximum speed or 0 mm / s.

13. The method of any one of claims 8 to 12, characterized in that the speed is reduced prior to arrival in the contact position (37, 65) at a relative distance (A) of ≤ 150 mm, preferably ≤ 100 mm, particularly preferably ≤ 50 mm.

14. The method of any one of claims 8 to 13, characterized in that the speed is reduced according to a linear function or an approximation function prior to arrival in the contact position (37, 65).

15. The method of any one of claims 8 to 14, characterized in that at least one sensor (61, 63) of the sensor device (62, 64) continuously transmits a distance value or a defined threshold of the relative distance (A) to the control device.

16. The method of any one of claims 8 to 15, characterized in that a contact force is exerted on the charging contact surface (11) by the adjustment drive (13, 49), wherein an electric motor (43, 58) of the adjustment drive is actuated by the control device.

17. The method according to claim 16, characterized in that a torque of the electric motor (43, 58) is detected by the control device, wherein the contact force is controlled by the control device in accordance with the torque of the electric motor.

18. The method according to any one of claims 8 to 17, characterized in that the control device determines a relative height of the charging contact (47, 48) and / or of the contact position (37, 65) above a road, wherein the control device determines a height of the vehicle above the road.