Inverted pantograph for a charging device for electric vehicles

Abstract

The invention relates to an inverted pantograph (1) for a charging device for electric vehicles and to a charging device having an inverted pantograph (1) of this kind. The inverted pantograph (1) has an actuator (2) which has a suspension (3) at a first end and a contact head (6), for making contact with the electric vehicle, at a second end, which is situated opposite the first end. The suspension (3) serves here for mounting on a supporting structure such as a mast or a hall ceiling. The actuator (2) is designed to lower the contact head (6) from an inoperative position into a charging position and to exert a pressing force on the contact head (6) in the charging position in order to charge the electric vehicle, and to raise the contact head (6) into the inoperative position after a charging process. According to the invention, the actuator (2) comprises a telescopic shaft (4) which has at least two partial shafts (5), which are axially slidable one into the other.

Description

[0001] Description

[0002] Inverse pantograph for an electric vehicle charging device

[0003] Technical area

[0004] The invention relates to an inverse pantograph for a charging device for electric vehicles and a charging device with such an inverse pantograph.

[0005] Technical background

[0006] Electric commercial vehicles such as buses or trucks can be charged using a cable / plug, similar to a car. This is problematic, however, because it usually requires direct human interaction, which is often not possible, particularly in the case of opportunity charging, such as charging at a bus stop during scheduled service while passengers are boarding and alighting. To automate this process, such vehicles are preferably charged using external power sources. For this purpose, there are exposed or automatically exposed contacts on the roof of the vehicles. Contact for charging is established using a lowering contact device connected to the charging device, so that the vehicle is contacted from above and out of reach of people.

[0007] In known applications, a conventional pantograph from rail vehicle technology is used as the current source, which is mounted upside down (inverse pantograph). Unlike in rail vehicles, contact between the charging device and the vehicle is established on the supply side, with the inverse pantograph lowering itself from top to bottom onto the electric vehicle. In certain previously known inverse pantographs, this performs a pivoting movement, so that both a lowering and a lateral movement are performed in a rotary motion.

[0008] In order to make a loading device equipped with an inverse pantograph usable for vehicles of different heights such as single-decker and double-decker buses, a large working stroke of the inverse pantograph is desirable.

[0009] The invention therefore has for its object to provide an improved inverse pantograph and an improved charging device for electric vehicles.

[0010] The invention solves this problem by an inverse pantograph according to claim 1 and a loading device according to claim 10. Advantageous embodiments of the invention form the subject matter of the subclaims.

[0011] Summary of the invention

[0012] A first aspect of the invention introduces an improved inverse pantograph for a charging device for an electric vehicle. The inverse pantograph has an actuator which has a suspension at a first end and a contact head for contacting the electric vehicle at a second end opposite the first end. The suspension is used for attachment to a supporting structure such as a mast or a hall ceiling. The actuator is designed to lower the contact head from a rest position into a charging position for charging the electric vehicle and to exert a contact force on the contact head in the charging position and to raise the contact head into the rest position after a charging process. According to the invention, the actuator comprises a telescopic shaft which has at least two partial shafts which can be pushed axially into one another.The inverse pantograph according to the invention enables a large working stroke, but requires little free space due to the use of the telescopic shaft. Unlike in the prior art, a holding shaft with the contact head does not have to be positioned in the space above the rest position of the contact head or pivoted sideways, thus occupying a correspondingly large space. Thus, the inverse pantograph according to the invention allows, for example, a lower ceiling height (logistics depot, bus station, etc.) with a constant working stroke and prevents the contact head from pivoting sideways, which requires correspondingly unobstructed and secured space to the side of the inverse pantograph.

[0013] Where directional terms and conditions such as "sideways", "above", "lower", "raise" etc. are used, these refer to a device that is installed and ready for operation.

[0014] The contact pressure is particularly preferably caused by a weight of the contact head and at least one partial shaft of the telescopic shaft. Or in other words, the contact pressure has no force component in the direction of the contact pressure other than the weight of the contact head and at least one partial shaft of the telescopic shaft. With this embodiment, a defined contact pressure can be caused in a simple manner, without the contact pressure having to be measured and, if necessary, a motor or the like having to be controlled. This simple measure also makes it possible to maintain a constant contact pressure, even if the contact height changes after contact has been made due to the electric vehicle being lowered in order to simplify the boarding and disembarking of passengers or unloading on a bound basis (often referred to as “kneeling”).

[0015] The contact force can, however, result from several acting forces. In particular, the contact force can be a difference between the weight of the contact head and at least one partial shaft of the telescopic shaft, and a counterforce. The counterforce can, for example, be a restoring force that is increased after the completion of a charging process to raise the contact head to the rest position.

[0016] The actuator can comprise a control unit and a cable drive connected to the contact head, which is designed to move the contact head between the rest position and the charging position in response to control signals from the control unit. The use of a cable drive allows the power transmission to be redirected to the side, thus enabling a low-profile arrangement. In this context, the term "cable drive" does not necessarily refer to a drive using a cable; similarly effective power transmissions such as chains, belts, and the like can, of course, also be used. The cable drive preferably has an electric motor.

[0017] The contact head is particularly preferably connected to the telescopic shaft via a spring bearing. The inverse pantograph has a first sensor which is designed to measure a first measured variable which is dependent on a force acting on the spring bearing and to output it to the control unit as a first measured signal. The control unit is also designed to stop the cable drive if the first measured signal exceeds a predetermined first threshold value. This makes it possible to lower the contact head in a controlled manner until the first sensor indicates that the contact head has touched the mating contacts of the electric vehicle, so that the force acting on the spring bearing exceeds the first threshold value. This makes more complex measures for position and distance detection unnecessary.

[0018] In versions of the inverse pantograph with a cable drive, a second sensor can be provided which is designed to measure a second measured variable that is dependent on a tensile force acting on the cable drive and to output it to the control unit as a second measurement signal. In this case, the control unit is also designed to stop the cable drive if the second measurement signal exceeds a predetermined second threshold value. This prevents the cable (chain, belt, etc., see above) from breaking if the contact head becomes caught or another mechanical problem occurs when lifting the contact head.

[0019] An energy storage device connected to the control unit and the cable drive can also be provided. In this case, the control unit is additionally designed to detect a supply voltage failure and, if a supply voltage failure is detected, to output a reset control signal to the cable drive. The cable drive is designed to raise the contact head into the rest position in response to the reset control signal. The energy storage device can be an electrical or electrochemical storage device, for example, but also a spring storage device or similar mechanical storage device. The energy storage device ensures that the contact head can be raised into the secured rest position and thus outside the area accessible to people and machines, despite a serious malfunction.

[0020] A second aspect of the invention relates to a charging device for charging an electric vehicle, wherein the charging device has an inverse pantograph according to the first aspect of the invention.

[0021] Short description of the characters

[0022] The invention is explained in more detail below with reference to exemplary embodiments. They show:

[0023] Figure 1 shows an embodiment of an inverse pantograph according to the invention in a rest position; Figure 2 shows the embodiment of the inverse pantograph according to the invention in a loading position;

[0024] Figure 3 shows a further embodiment of an inverse pantograph according to the invention; and

[0025] Figure 4 shows a third embodiment of an inverse pantograph according to the invention.

[0026] From detailed character description

[0027] Figure 1 shows an embodiment of an inverse pantograph 1 according to the invention in a rest position. The inverse pantograph 1 has an actuator 2 which is provided for lowering a contact head 6 arranged at one end of the actuator 2 - during normal operation the lower end of the actuator 2 - from the illustrated rest position into a charging position. The contact head 6 serves to establish electrical contacts with a mating contact arrangement arranged on the roof of an electric vehicle via contact rails 7. For this purpose, the contact head 6 is lowered onto the mating contact arrangement and pressed onto the mating contact arrangement by the gravity of the contact head 6 and parts of the actuator 2 connected to it.

[0028] The other end of the actuator 2 - the upper end during normal use - is connected to a suspension 3 which serves to connect the actuator 2 to a hall ceiling, a holding bridge, a laterally positioned mast or the like. In the exemplary embodiment shown, the actuator 2 partially projects upwards beyond the suspension 3. Depending on the location of use, however, any suitable relative arrangements of the end of the actuator 2 connected to the suspension 3 and the suspension 3 can be provided. Within the scope of the invention, attaching the suspension to an end of the actuator 2 other than the end at which the contact head 6 is arranged is considered to be implemented if actuation of the actuator 2 during normal operation changes the relative vertical distance between the suspension 3 and the contact head 6.

[0029] Figure 2 shows the exemplary embodiment of the inverse pantograph 1 according to the invention from Figure 1 in a charging position. In the charging position, the contact head 6 is lowered compared to the rest position, so that an electric vehicle positioned below the inverse pantograph 1 is contacted for a charging process. In the charging position, the actuator 2 is extended compared to the rest position to overcome the height difference between the two positions. As a result, a telescopic shaft 4 provided according to the invention is visible in Figure 2, which comprises at least two (exactly two in the exemplary embodiment shown) partial shafts 5 which can be pushed axially one inside the other. The number of partial shafts 5 can be increased in order to increase the height difference between the rest and charging positions relative to the overall height of the inverse pantograph 1 in the rest position.

[0030] In the embodiment of Figures 1 and 2, spring mounts 12 are also provided, which connect a base of the contact head 6 to the contact rails 7, so that the contact rails 7 are spring-mounted on the base. This allows for a certain degree of height compensation if the electric vehicle positioned under the inverse pantograph 1 is not aligned exactly horizontally.

[0031] Figure 3 shows a further exemplary embodiment of an inverse pantograph 1 according to the invention, the inverse pantograph being shown in the rest position. The objects designated by the same reference numerals designate identical or similar objects as those explained in the other figures. For ease of illustration, the inverse pantograph of Figure 3 has been shown without one of the side walls of a housing of the actuator 2. This makes the telescopic shaft 4 arranged inside the housing in the rest position visible. Also visible is a cable guide 16 which is composed of members which can be pivoted relative to one another and on which cables 17 for conducting electrical power and control signals to the contact rails 7 of the contact head 6 are guided. The cable guide 16 can follow movements of the telescopic shaft 4 and in the process compensate for changes in the height of the contact head 6.When the contact head 6 is lowered from the rest position shown in Figure 3 into the loading position, the cable guide 16 extends downward out of the housing of the actuator 2. When the contact head 6 is raised back into the rest position, the cable guide 16 is lifted back into the housing in a bending movement, so that it finally assumes the inverted U-shape shown.

[0032] Figure 4 shows a third exemplary embodiment of an inverse pantograph 1 according to the invention, which structurally corresponds at least largely to the example in Figure 3. Thus, the exemplary embodiment in Figure 4 also has a cable guide 16, as explained above. The actuator 2 of the inverse pantograph 1 in Figure 4 is equipped with a cable drive 11, which is designed, for example, with deflection pulleys 9 and a cable 8, for example a wire rope. The actual drive here is an electric motor 10, which is designed to wind the cable 8 onto a spindle or unwind it from there in order to move the contact head 6 between the rest and charging positions. Of course, other configurations of a cable drive than the one shown can be selected. Also, the term "cable" here does not necessarily have to be understood as a cable in the true sense; belts or chains can also be used.

[0033] A first sensor 13 and a second sensor 14 are arranged on the contact head 6 of the inverse pantograph of Figure 4, with the first sensor 13 being arranged on one of the spring bearings 12. Several first sensors 13 can also be provided, for example, one on each spring bearing 12.

[0034] The first sensor 13 serves to directly or indirectly measure a force acting on the spring bearing 12 and to output a measurement signal representing this force to a control unit 15. The control unit 15 can be arranged anywhere and does not have to be located at the mounting location of the actuator 2. A remote arrangement of the control unit 15, for example, in a server, is also possible. For this reason, the representation of the control unit and the signal lines connected to it should also be understood as purely schematic.

[0035] The control unit 15 can use the measurement signal received from the first sensor 13 to detect when the contact head 6 is placed on the counter contact arrangement of the electric vehicle, whereupon the control unit 15 can stop the electric motor 10 of the cable drive 11 in order to prevent the cable 8 from unnecessarily unwinding.

[0036] The inverse pantograph 1 of the embodiment of Figure 4 is additionally equipped with a second sensor 14, which can be arranged, for example, between the cable 8 and the contact head 6 and is designed to directly or indirectly measure a tensile force acting on the cable drive 11 and to transmit a measurement signal representing the measured tensile force to the control unit 15. The control unit 15 can use the measurement signal received from the second sensor 14 to stop the electric motor 10 of the cable drive 11 if the measurement signal indicates that the tensile force on the cable 8 increases above a certain level. This can be the case, for example, when the rest position is reached or when the measuring head 6 becomes jammed. In the latter case, the control unit 15 can output an error signal to draw attention to this error.

[0037] The sensors 13 and 14 can measure the aforementioned measured variables in various ways. For example, the tensile force acting on the cable 8 can also be determined based on a measurement of the drive current flowing into the electric motor 10, so that the second sensor 14 is designed as a current sensor. The first sensor 12 can equally indicate a relaxing or tensioning of springs in the spring bearing 12, with the control unit 15 evaluating the signal in different ways accordingly. The invention has been explained in more detail using exemplary embodiments. The exemplary embodiments serve merely to improve understanding of the invention and are not intended to limit the invention, which is defined exclusively by the following patent claims.

[0038] Reference symbol list

[0039] 1 inverse pantograph

[0040] 2 actuators

[0041] 3 Suspension

[0042] 4 telescopic shaft

[0043] 5 Partial share

[0044] 6 Contact head

[0045] 7 Contact rail

[0046] 8 rope

[0047] 9 pulley

[0048] 10 Electric motor

[0049] 11 Rope drive

[0050] 12 spring bearing

[0051] 13 first sensor

[0052] 14 second sensor

[0053] 15 Control unit

[0054] 16 Cable routing

[0055] 17 cables

Claims

Patent claims 1. An inverse pantograph (1) for a charging device for an electric vehicle and having an actuator (2) which has a suspension (3) at a first end and a contact head (6) for contacting the electric vehicle at a second end opposite the first end and is designed to lower the contact head (6) from a rest position into a charging position for charging the electric vehicle and to exert a contact force on the contact head (6) in the charging position and to raise the contact head (6) into the rest position after a charging process, characterized in that the actuator (2) comprises a telescopic shaft (4) which has at least two partial shafts (5) which can be pushed axially into one another.

2. The inverse pantograph (1) of the preceding claim, wherein the contact force is caused by a weight force of the contact head (6) and at least one partial shaft (5) of the telescopic shaft (4).

3. The inverse pantograph (1) of the preceding claim, wherein the contact force is a difference between the weight of the contact head (6) and the at least one partial shaft (5) of the telescopic shaft (4) and a counterforce.

4. The inverse pantograph (1) of any one of the preceding claims, wherein the actuator (2) comprises a control unit (15) and a cable drive (11) connected to the contact head (6), which is designed to move the contact head (6) between the rest position and the loading position in response to control signals from the control unit (15).

5. The inverse pantograph (1) of the preceding claim, wherein the cable drive (11) has an electric motor (10).

6. The inverse pantograph (1) of one of the two preceding claims, in which the contact head (6) is connected to the telescopic shaft (4) via a spring bearing (12), wherein the Inverse pantograph (1) has a first sensor (13) which is designed to measure a first measured variable dependent on a force acting on the spring bearing (12) and to output it as a first measuring signal to the control unit (15), wherein the control unit (15) is also designed to stop the cable drive (11) when the first measuring signal exceeds a predetermined first threshold value.

7. The inverse pantograph (1) according to one of claims 4 to 6, comprising a second sensor (14) which is designed to measure a second measured variable which is dependent on a tensile force acting on the cable drive (11) and to output it as a second measuring signal to the control unit (15), wherein the control unit (15) is also designed to stop the cable drive (11) when the second measuring signal exceeds a predetermined second threshold value.

8. The inverse pantograph (1) according to one of claims 4 to 7, comprising an energy storage device connected to the control unit (15) and the cable drive (11), wherein the control unit (15) is additionally designed to detect a failure of a supply voltage and, in the event of a detected failure of the supply voltage, to output a reset control signal to the cable drive (11), and wherein the cable drive (11) is designed to raise the contact head (6) into the rest position in response to the reset control signal.

9. A charging device for charging an electric vehicle, the charging device comprising an inverse pantograph (1) according to one of the preceding claims.

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