DE102012208499A1 - Fixing device for supporting traction battery, has battery container to receive traction battery, stop clamped by clamping element against fixing element that is attachable to vehicle, and contact surface between stop and fixing element - Google Patents

Abstract

The fixing device comprises a battery container for receiving the traction battery. A stop (12) is clamped by the clamping element against the fixing element (11), and the fixing element is attachable to the vehicle. The fixing element is fixed to the battery container and the clamping element. The stop on the vehicle is fastened. The stop is mounted on the battery box and the fixing element is attachable to the vehicle. A contact surface is formed between the stop and the fixing element located in the clamped state.

Description

The invention relates to a device for fixing a replaceable traction battery in an underbody space of an electrically driven vehicle. Preferably, the device also supports the inclusion of a battery trough mounted in the vehicle on the underside of the vehicle. In addition, the invention relates to a vehicle that is equipped for a battery change with the help of the generic device.

In the course of the scarcity of fossil fuels and increased pollutant pollution by an increasing individual traffic worldwide, the search for alternative drive concepts for internal combustion engines is gaining in importance. For example, electrically powered vehicles are currently being treated as the future of individual transport. In particular, if the primary energy used for the operation of the electric vehicles of regenerative nature such as sun, wind or tides, a significant improvement in the environmental performance of individual transport can be achieved by its electrification.

However, a nationwide collection of electrically powered vehicles are still the high cost of the energy storage required battery and their limited storage capacity and their compared to a refueling long charging time. The currently available battery technology does not allow the energy density of fossil fuels, so that the range of purely electrically powered vehicles does not meet the needs of many consumers. Since charging the battery can take several hours, the electric vehicle is not easily suitable for long-distance travel.

However, one approach to the upgrading of electric vehicles for long-distance travel are battery replacement systems, as for example US 2009082957 A1 are known. Thereafter, the vehicles are equipped with replaceable batteries, which can be replaced in a nationwide network of battery changing stations against fully charged batteries, if required by their state of charge. For this purpose, batteries charged in the battery replacement station are kept in stock. The change process takes much less time than charging the battery, so that the long charging time for the driver loses relevance. The discharged battery removed from the vehicle is recharged at the change station and is then available for further replacement.

In such a model, the driver does not purchase the expensive traction battery, which significantly reduces the initial investment for an electric vehicle. Rather, for example, the operator of the changing station or another service provider owner of the battery, which in turn can finance through appropriate user fees.

The attractiveness of such an infrastructure depends crucially on whether it makes it possible to make available a battery replacement system at a reasonable cost, which allows a rapid change of the accumulator comparable to a current refueling process. Here, it is important to coordinate the mechanical and electrical interfaces between the vehicle, battery and changeover station under optimal technical and economic aspects.

From the US 20100071979 A1 a battery replacement system is known in which the traction battery is mounted in a frame construction. On the vehicle there are four snap locks, which are actuated by also mounted on the vehicle electric motors and various transmission components. The latches each engage with a bolt attached to the battery to lift the battery from the vehicle underbody side into the vehicle and fix it there.

Once the traction battery has been installed in the compartment-side space of the vehicle, it must be securely held there. Accelerations of up to 10 g acting on the vehicle must not lead to the traction battery slipping in the compartment-side space of the vehicle. Any slippage of the up to 500 kg traction battery can have a negative effect on the driving stability and thus reduce driving safety.

The invention has for its object to ensure a secure mounting of removable traction batteries in electrically powered vehicles.

This object is achieved by a fixing device for mounting a traction battery in an underbody space of an electrically driven vehicle with the features according to claim 1.

Advantageous embodiments of the invention can be found in the dependent claims.

The fixing device according to the invention initially comprises a battery tray for receiving the traction battery, a clamping element and a stop. Furthermore, the fixing device comprises a fixing element which can be clamped with the clamping element against the stop. Optionally, in this case, said fixing on the battery tray be fastened while the bracing element and the stop on the vehicle can be fastened or alternatively the bracing element and the stopper are attached to the battery tray, while the fixing element is fastened to the vehicle. According to the invention, a knurl-like contact surface is arranged between the stop and the fixing element in the clamped state. Said knurl-like contact surface can be arranged in an advantageous embodiment of the invention at the stop or alternatively on the fixing element.

The knurl-like contact surface is designed such that its tips easily dig into the opposing further contact surface in the clamped state and thus cause a micro-toothing effect. Said toothing effect complements the frictional contact between the bracing element, the fixing element and the stop by another positive contact. As a result, the Querhaltefähigkeit the entire system is significantly increased. Preferably, the knurled contour is characterized by intersecting grooves. These cause a positive securing against slipping within the entire horizontal plane.

In an advantageous embodiment of the invention, the knurl-like contact surface made of a hardened material, while standing with the knurl-like contact surface in the clamped state in contact further contact surface made of an uncured material. This ensures that the embossed by the knurl-like contact surface micro-toothing can dig into the softer opposite contact surface, so as to form a microforming. Due to the fact that the knurled contact surface is hardened, its structure is retained even after several traction battery changes and is not significantly worn by the acceleration forces applied during the drive.

In an advantageous embodiment of the fixing device according to the invention, the bracing element is designed as a lever. In this case, in a further advantageous embodiment of the invention, the fixing element may be formed as a bolt. Preferably, four of said bolts are attached at four different locations on the battery trough. Conveniently, these four locations are located on two opposite sides of the battery tray. On the body of the vehicle are in a further advantageous embodiment of the invention at appropriate points bracing, in particular in the form of levers, which interact with the bolt formed as fixing elements for lifting and fixing the traction battery.

Said bolts are advantageously smooth surface, so they can be made very easily with conventional manufacturing processes such as turning, pulling or pressing. A particularly also smooth surface running lever presses to fix the traction battery, the bolt against the stop, which has said knurled contact surface in an advantageous embodiment of the invention. This knurl-like contour, which can be produced in particular by a non-cutting manufacturing process, such as rolling or pressing, thus eats into the initially surface-smooth surface of the bolt and thus represents the desired form fit.

In an alternative embodiment of the invention, the fixing element, in particular the bolt, may also be formed surface-structured. Preferably, such a surface structure of the bolt is hardened and eats against the stop in the now smooth and in particular uncured stop when tightening.

In an advantageous embodiment of the invention, the fixing device further comprises a spindle with a spindle head, via which a drive torque from an actuator to the spindle is transferable, and a form-locking connected to the spindle, movable in the direction of the spindle axis and rotatably mounted threaded nut. A force arm of the lever is in this case directly connected to the threaded nut such that a movement of the threaded nut in the direction of the spindle axis causes a pivotal movement of the lever about its pivot point. In particular, when the fixing element is designed as a bolt, this moves during bracing along the lever surface to the point where it has reached the stop. Said wandering of the fixing element, in particular of the bolt, along the lever surface is advantageously facilitated by the fact that the knurl-like structure is located at the stop and not at the bolt. In a design of the knurl-like structure on the bolt a circumferential knurling would be a hindrance to the above-described lever kinematics. It would be expedient here only circumferential grooves, which are formed in the direction in which the bolt moves along the lever surface when lifting the battery. However, this would make an additional stop in the axial direction of the vehicle by positive engagement impossible. Accordingly, an embodiment of the invention is preferred in which the knurled structure is formed on the stop, while the bolt is made smooth surface.

It is also possible and of the invention comprises, in a further advantageous embodiment, both the fixing element, in particular the bolt, as well as the stop with a knurled To train structure. In this case, it is advantageous to make both parts hardened, at least on their contact surface, in order to delay the formation of smoothing effects.

Furthermore, a design of the knurled structure on the lifting surface of the bracing element, in particular of the lever, in principle conceivable. In view of the lateral rigidity of the arrangement, however, a formation of the knurling on the stop is also preferable here.

In the following the invention with reference to the embodiments illustrated in the figures will be described and explained in more detail.

Show it:

1 a battery tray and an underbody space of an electrically driven vehicle for receiving the battery trough,

2 the battery tray after 1 when installed,

3 a view of one side of the lower-level installation space,

4 a side view of the battery trough,

5 a side view of the built-in in the bottom space space battery tray,

6 a fixing device according to an embodiment of the invention in cross-section,

7 in the 6 shown fixing device in perspective view,

8th a perspective view of a mountable on the vehicle or on the battery tray part of a fixing device according to an embodiment of the invention and

9 an enlarged view of a knurled contact surface on a stop of the in 6 represented part of the fixing device,

1 shows a battery tray 1 and an underbody space 2 an electrically powered vehicle for receiving the battery trough 1 , For the sake of simplicity, the representation of the vehicle is here on its lower-side space 2 reduced to accommodate the traction battery. At the bottom-side space 2 are on the long sides of each two passive actuators 3 for lifting and fixing the battery trough 1 shown. The actors 3 comprise a spindle, a threaded nut connected in a form-fitting manner and non-rotatably mounted, and a pivotable lever connected to the threaded nut. The actor 3 is referred to as passive, since he himself has no motor drive for its operation. Details about the here proposed Aktorik are in the 6 ff. explained in more detail.

The actors 3 are operated vertically from the underbody side with a suitable tool. In the battery tray 1 are through holes 4 provided, through which the tool can be introduced to a head of the spindle in the lower space space 2 to grab and transmit over this one generated by an electric motor torque to the spindle. Tool and electric motor are arranged in a changing station, in which the vehicle enters for a battery change. Accordingly, these components do not need to be carried on board the vehicle, thereby saving costs and space.

By turning the spindle, levers coupled with the spindle pull the battery tray 1 in the installation space 2 one, so that the in 2 shown state results.

3 shows a view on one side of the bottom-side space 2 , where no battery tray 1 is installed. Accordingly, the levers mounted on the spindle which can be seen here are located above the threaded nut 6 in a relaxed state. The installation space 2 also includes four shots 7 for on the battery tray 1 correspondingly arranged guide pins 8th (please refer 4 ) as well as a socket 9 , which are for inclusion of in 4 illustrated plug 10 is provided. Rifle 9 and plugs 10 cause the electrical connection between the battery and the vehicle. The electrical connection system contacts both the power cables and signal lines, which transmit state signals from the battery to an in-vehicle controller, thus enabling condition monitoring of the battery, for example.

4 shows a side view of the battery trough 1 , In addition to the elements already mentioned are on two opposite side surfaces in each case in the vicinity of the corners and just above the surface facing the ground in the form of bolts configured fixing elements 11 provided in which the levers 6 intervene to the battery tray 1 in the lower-level space 2 to pull and fix him there. Overall, the battery trough includes 1 thus four bolts distributed over the two opposite side surfaces, which interact with vehicle-mounted levers 6 are provided.

5 shows a side view of the in the bottom-side space 2 built battery tray 1 , The spindle 5 has the threaded nut attached to it and thus the force application point of the lever 6 each pulled down, leaving the battery tray 1 firmly in the compartment-side space 2 is braced against the bolt.

A detailed representation of an advantageous embodiment of the device according to the invention is shown in the following figures.

For identical or equivalent elements of the invention, identical reference numerals are used.

6 shows a fixing device according to an embodiment of the invention in cross section. 7 shows said fixing in a perspective view.

The fixing device essentially comprises a clamping element with a lever 6 , a fixing element 11 and a stop 12 , The lever 6 is about a threaded nut 13 with a spindle 5 connected. This puts the threaded nut 13 on a power arm of the lever 6 so that with a vertical movement of the threaded nut 13 the lever 6 a rotation around his pivot learns. To this vertical translational movement of the threaded nut 13 to achieve this is rotatably mounted within the illustrated arrangement. If the spindle 5 is rotated, the nut moves accordingly 13 in a vertical direction upwards or downwards. During a rotary movement of the spindle 5 that the threaded nut 13 drives down, the load arm of the lever braces 6 the fixing element 11 against the attack 12 , The fixing element 11 This is advantageously designed as a bolt.

The rotational movement of the spindle 5 is initiated by an external actuator. In this context, external means that the actuator designed, for example, as an electric motor with a corresponding tool is located neither on the battery tray nor inside the vehicle. Rather, this z. B. part of a battery replacement station. This has the advantage that on the one hand expensive and on the other hand also heavy actuator does not have to be carried in the vehicle. It should also be noted that for lifting the traction battery and for its secure fixing at least four of the illustrated fixing devices are provided. Accordingly, in the case of the passive solution represented here, in comparison with an active solution in which the motor drive also has to be guided in the vehicle, four, in particular electromotive drives, are dispensed with.

For secure holding of the traction battery, which can weigh up to 500 kg, enormous minimum delivery forces are necessary in a pure traction. In a purely positive connection between the lever 6 , the bolt and the stop 12 the necessary clamping force is calculated for an assumed battery mass of 500 kg, a coefficient of friction μ = 0.1 and an acceleration of 10 g F = 500 kg × 9.81 m / s ² × _10/4 / μ / 2 = 62,500 N

Such high clamping forces are difficult to achieve in the usually limited space below the vehicle. Therefore, as in the 8th and 9 can be seen better, an additional positive connection between the stop 12 and the bolt realized to reduce the force acting on the bolt delivery force, which is necessary for secure holding the traction battery.

So shows 8th a perspective view of a mountable on the vehicle or on the battery tray part of a fixing device according to an embodiment of the invention. The operation of this part of the fixing was already in connection with the 6 and 7 explained, so that here further explanations are omitted. As in 8th is to recognize, is at the stop 12 a knurled contact surface 14 educated. At this knurled contact surface 14 is in the tightened state, the fixing, in particular the bolt on. The bolt is made by means of the lever 6 against the knurled contact surface 14 pressed, so that the knurling can eat into the bolt and causes an additional positive locking. Said gnawing is made easier by the fact that the stop 12 in the area of the knurled contact area 14 surface hardened, while the bolt is formed uncured.

In the enlarged view 9 It can also be seen that the knurl-like contact surface 14 is formed by two intersecting groove patterns. In this way, a positive connection is achieved within the entire plane in which said grooves are arranged.

In 8th is also a tool interface 15 to recognize over which the already mentioned external actuator can transmit a torque to the spindle. The illustrated tool interface 15 is trained as an outdoor dancer.

LIST OF REFERENCE NUMBERS

1

battery tray

2

bottom side installation space

3

actuator

4

Through holes

5

spindle

6

lever

7

Recordings

8th

guide pins

9

Rifle

10

plug

11

fixing

12

attack

13

threaded nut

14

knurled contact surface

15

Tool interface

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2009082957 A1 [0004]
• US 20100071979 A1 [0007]

Claims (8)

Fixing device for mounting a traction battery in a compartment-side space of an electrically driven vehicle, wherein the fixing device - a battery tray ( 1 ) for holding the traction battery, - a clamping element, - a stop ( 12 ) and - one with the clamping element against the stop ( 12 ) clampable fixing element ( 11 ), wherein - the fixing element ( 11 ) on the battery tray ( 1 ) is fixed and the tensioning element and the stop ( 12 ) are fastened to the vehicle or - the tensioning element and the stop ( 12 ) on the battery tray ( 1 ) and the fixing element ( 11 ) is attachable to the vehicle, one between the stop ( 12 ) and the fixing element ( 11 ) in the tensioned state lying contact surface ( 14 ) is knurled. Fixing device according to claim 1, wherein the stop ( 12 ) the knurl-like contact surface ( 14 ) having. Fixing device according to claim 1, wherein the fixing element ( 11 ) the knurl-like contact surface ( 14 ) having. Fixing device according to one of the preceding claims, wherein the knurl-like contact surface ( 14 ) of a hardened material and one with the knurl-like contact surface ( 14 ) in the tensioned state in contact further contact surface consists of an uncured material. Fixing device according to one of the preceding claims, wherein the clamping element comprises a lever ( 6 ). Fixing device according to claim 5, wherein the fixing device - a spindle ( 5 ) with a spindle head, via which a drive torque from an actuator to the spindle ( 5 ) is transferable, and - one with the spindle ( 5 ) positively connected, movable in the direction of the spindle axis and rotatably mounted threaded nut ( 13 ), wherein a power arm of the lever ( 6 ) with the threaded nut ( 13 ) is directly connected such that a movement of the threaded nut ( 13 ) in the direction of the spindle axis pivotal movement of the lever ( 6 ) around his pivot. Fixing device according to one of the preceding claims, wherein the fixing element ( 11 ) is designed as a bolt. Electrically powered vehicle having at least four fixing devices according to one of the preceding claims, wherein - the fixing elements ( 11 ) on the battery tray ( 1 ) and the bracing elements and the associated stops are fastened to the vehicle or - the bracing elements and the associated stops ( 12 ) on the battery tray ( 1 ) and the fixing elements ( 11 ) are attached to the vehicle.

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