DE9410158U1 - Passenger cars with electric drive - Google Patents

Description

Lennart Preu 08 June 1994

D-14169 Berlin

ATO44.G1

Passenger cars with electric drive

Description

The invention relates to a passenger car of the type specified in the preamble of claim 1.

Such passenger cars have been known as prototypes for some time and have recently been built in small series.

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AT044.G1 Sheet 2

Vehicles can also be purchased. The vehicles currently available are conversions of small or compact cars that are mass-produced with a conventional combustion engine.
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To operate such a vehicle under everyday conditions and with reasonable operating costs, a voluminous set of relatively inexpensive batteries (such as lead-acid batteries) is required, which guarantee a minimum range in city traffic of around or over 50 km and a maximum speed of around or over 80 km/h. This set of batteries is usually housed in the trunk and part of the interior or passenger compartment, which also makes it possible to design a battery heater (which is essential for winter operation) in the conventional way as a hot water heater.

This way of accommodating the battery pack significantly limits the use of the trunk and passenger compartment. Some of these passenger cars can even only be used as two-seaters. The acceptance of these vehicles is low due to the resulting significant limitations in their usability.

The invention is therefore based on the object of designing a passenger car of the type mentioned at the outset in such a way that the battery set required for everyday operation can be accommodated without any significant restrictions on the interior and trunk space.

This object is achieved by a passenger car having the features of claim 1.

AT044.G1 Sheet 3

The invention includes the idea of arranging the battery pack in several areas of the vehicle instead of in a single large block, namely in areas in which, in a vehicle with a comparable structure and a combustion engine, there are usually components that are either not required at all for an electric vehicle or whose omission leads to comparatively minor restrictions in terms of usability. Such areas are in particular a large part of the engine compartment and the areas of the vehicle structure intended for the fuel tank and/or the spare wheel.

In addition to maintaining utility value in terms of the use of the interior and trunk, such an arrangement has the advantage that the battery pack can be installed in a conventional body structure without any structural changes to it. In an electric vehicle that is based on a body developed for a vehicle with a combustion engine, this significantly reduces manufacturing costs, makes handling and maintenance easier, ensures that the warranty for the body is maintained and avoids loss of value.

In a practical design, a total of three battery groups are provided: a first group in the engine compartment consisting of six lead-acid fleece batteries in a special small car, a second group in front of the rear axle instead of the fuel tank in the special car consisting of four batteries arranged next to each other transversely to the vehicle's longitudinal axis, and a third group specifically

AT044.G1 Sheet 4

A group of four batteries arranged in a ring that fits into the outer contour of a spare wheel mounting area - underneath the trunk instead of a spare wheel.
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The individual battery groups are preferably each housed in a separate, essentially hermetically sealable battery box, which can be made of glass fiber reinforced plastic and can be screwed and/or glued to the vehicle body. If a vehicle type is otherwise equipped with an internal combustion engine, screwing is preferably carried out at suspension points that are already present, while any additional fastening that may be required is preferably carried out by gluing.

The connection for charging the batteries, which can be connected to an external power supply, is designed in a practical way to facilitate handling so that it is accessible from the side of the vehicle, in particular instead of a fuel filler neck present on a comparable passenger car with a combustion engine.

A particularly advantageous design is that the batteries are assigned an electric heating device, which can be used to optionally heat them when charging. Compared to a vehicle without battery heating, a vehicle with this design has significantly improved winter suitability and a longer battery life. In contrast to conventional hot water heating, an electric battery heating system can be installed cheaply.

AT044.G1 Sheet 5

This can also be achieved with a distributed battery pack and also results in a significant weight saving.

The electric heating device preferably has several separately controllable heating elements, each assigned to one of the battery groups. This enables specific heating to be provided in accordance with the different exposures of the individual battery groups, whereby the corresponding settings can be made manually or automatically according to the outside and/or battery temperature.

In a simple and cost-effective design, the heating device comprises heating foils of a known type, which are in surface contact with the battery casing - preferably on the underside of the batteries - and whose surface facing away from the battery casing has thermal insulation. In order to be able to accommodate the heating elements - especially these heating foils - in a cost-effective manner, the battery boxes have bases with central areas that are recessed compared to the edge areas and/or separate support ribs for essentially load-free accommodation of the heating elements and the thermal insulation associated with them, if applicable.

In an advantageous embodiment of the overall power supply, the electric heating device is connected to the control unit and has means for controlling the heating device depending on the outside temperature during charging as well as means for selectively starting up the heating device outside of charging times.

ATO44.G1 Sheet 6

For the possible future use of Ni-Cd elements as a battery set for the passenger car according to the invention, the use of battery cooling instead of battery heating may be expedient, which is implemented in a largely analogous manner to the heating designs described above in a distributed design, i.e. with cooling devices (fans, thermoelectric cooling elements, water bags, etc.) assigned to the individual battery groups and controlled individually.

Advantageous further developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention using the figures. They show:

Figure 1 is a schematic side view of a passenger car according to an embodiment of the invention,

Figure 2 is a schematic plan view of the passenger car according to Fig. 1,

Figure 3 is a schematic cross-sectional view of a battery box for a battery group in the passenger car shown in Fig. 1 and 2,

Figure 4a is a highly simplified block diagram of the battery arrangement and heating device in a special version of the passenger car shown in Fig. 1 and 2 and

Figure 4b is a highly simplified block diagram of the battery arrangement with modified cable routing and measuring devices compared to Fig. 4a.

AT044.G1 Sheet 7

Figures 1 and 2 show, in the form of a phantom representation, the side view and the top view of a small car originally designed and manufactured with a conventional combustion engine and converted to electric drive.

In the small car 1, a first battery group 4 is arranged in the engine compartment 2 above the front axle 3 (shown here purely geometrically as a wheel center connecting axis). A second battery group 5 is arranged in place of the fuel tank originally installed there in front of the rear axle 6 below the rear seats (not shown in the figure). A third battery group 7 is arranged in the area above and behind the rear axle 6 instead of the spare wheel usually housed there.

To charge the batteries, instead of the tank filler neck present in the conventionally powered vehicle, a Schuko plug connection 9 is provided above and in front of the rear wheels 8, with which - although not shown in the figure - all batteries are connected via a converter/control unit 10 provided in the engine compartment 2 above the first battery group 4 (only shown in Fig. 1).

Furthermore, the battery groups 4, 5 and 7 are connected via the converter/control unit 10 to a motor-gear unit 11 comprising a servo synchronous motor, arranged essentially to the side of and below the first battery group 4, which drives the front wheels 12 of the vehicle 1.

AT044.G1 Sheet 8

Fig. 2 shows in more detail how the battery groups are formed from individual lead-acid fleece batteries of a known design:

The first battery group 4 comprises a total of six batteries 41 to 46 in a battery box made of fiber-reinforced synthetic resin 40, as well as a measuring box 47 with a measuring strip for connecting measuring devices for determining the battery status during maintenance. The batteries 41 and 42 are arranged one behind the other in the left half of the engine compartment 2, transverse to the vehicle's longitudinal axis 13, and the remaining four batteries 43 to 46 are arranged one behind the other in the right half of the engine compartment, parallel to the vehicle's longitudinal axis. All batteries 41 to 46 in the first group are in one plane.

The second battery group 5 comprises two batteries 51, 52 and 53, 54 arranged side by side transversely to the vehicle’s longitudinal axis 13 on the left and right, and a measuring box 55 in a battery box 50. The battery box 50 is designed in its shape and fastening means essentially in accordance with the fuel tank originally present in the original vehicle, so that it can be screwed to the vehicle body at the suspension points provided for its fastening.

The third battery group 7 comprises four batteries 71 to 74 and a measuring box 75 in a battery box 70. The batteries 71 to 74 are arranged in such a way that they form a kind of closed ring, which gives the battery box 70 external dimensions that allow it to be inserted into

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AT044.G1 Sheet 9

the trunk floor essentially instead of the spare wheel. To ensure the mobility of the vehicle in the event of a flat tire, a tire inflation bottle (not shown) is provided.
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In Fig. 3, the battery box 50 from Fig. 2 is shown in a cross-sectional view along the line A-A.

In the figure it can be seen that the battery box is constructed from a substantially trough-shaped lower part 50a and an upper part 50b, which are detachably connected to one another via lateral screw connections 50c and 50d. The bottom of the lower part 50a has a recess 50e in the middle area. A layer of recycled material 50f and above it a heating foil 50g - symbolized in the figure by a wavy line - are inserted in such a way that the recess is filled with it. The battery 53 rests on the bottom sections of the lower part 50a that laterally delimit the recess 50e. The space between the battery cover and the underside of the battery box upper part 50b is filled with a layer of insulating rubber (ISO rubber) 50h, which is pressure-elastic and presses the battery 53 against the bottom of the battery box.

Figures 4a and 4b show, in highly simplified block diagrams, the connection of the battery groups 4, 5 and 7 shown in Fig. 1 and 2 with connected measuring devices or measuring connections for battery status detection and with the converter/control unit 10 for power supply of the drive unit as well as the most important components.

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ATO44.G1 Sheet 10

Components for battery heating are shown in two different versions.

In Fig. 4a it can be seen that the first, second and third battery groups 4, 5 and 7 are each connected to the converter/control unit 10 via a separate pair of power lines 4L, 5L and 7L, respectively, whereby a series connection of the battery groups is implemented within the converter/control unit. In the lines (in the above-mentioned measuring boxes 47, 55 and 75) there is a current measuring device A4, A5 and A7 respectively and between the battery or battery box terminals there is a voltage measuring device U4, U5 and U7 respectively for monitoring the battery condition and charging control.
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Alternatively - in a particularly cost-effective version - according to Fig. 4b, the battery groups 4, 5 and 7 in the vehicle are wired in series with a power cable L that connects them directly to each other and to the converter/control unit, whereby the converter/control unit only has one positive and one negative battery connection. Only one voltmeter V and one ammeter A are provided for continuous current and voltage measurement (integrated across the battery groups), whereby measuring strips - shown symbolically in the figure - are assigned to the individual battery groups. (The other elements correspond to Fig. 4a and have the same reference numbers as there.)

The integrated converter/control unit 10, whose control part has a microprocessor control, is equipped with a

AT044.G1 Sheet 11

Control element ("accelerator pedal") 14 and the motor windings of the servo synchronous motor of the motor-gear unit 11. The extraction of stored energy from the batteries for driving can be controlled depending on their temperature and electrochemical state. Furthermore, the converter/control unit can optionally be connected to an external power network (shown with dotted lines) for charging the batteries via the charging connection 9.

Finally, the control unit has three separate inputs El to E3 for receiving temperature signals from one temperature sensor T4, T5 or T7 assigned to battery groups 4, 5 or 7, respectively, and three outputs A4, A5 and A7 connected to separate battery heaters 40g, 50g or 70g of battery groups 4, 5 and 7 for supplying the battery heaters with heating current depending on an evaluation of the displays of the temperature sensors T4, T5 and T7 and, if necessary, the displays of the current and voltage meters A4, A5 and A7 as well as U4, U5 and U7 carried out in the microprocessor unit. This enables individual consideration of the temperature conditions in the individual battery boxes as well as group-wise consideration of the battery status both when charging the batteries and the heating that may be carried out in the process, and when driving.

In an alternative, simple and cost-effective design, the battery heating is controlled only depending on the battery and/or the outside temperature (without current and/or voltage measurements).

AT044.G1 Sheet 12

The measuring devices for current, voltage and temperature A4, U4, T4 or A5, Ü5, T5 or A7, U7, T7 assigned to the first, second and third battery groups 4, 5 and 7 in the embodiment shown in Fig. 4 are looped in via the measuring strips in the measuring boxes 47, 55 or 75 or are permanently arranged in them, which were shown in Fig. 2. In the case of a fixed arrangement, the display of the measurement results on the dashboard on request is expedient.

The current and voltage meter provided in the simplified version mentioned above can be spatially assigned to the converter/control unit, whereby the display can also be shown - permanently or on demand - on the dashboard.

The control unit also has a switch - which is not shown in the figure - for manually switching on the battery heating when required. This allows the driver, independently of the automatic control, to heat the batteries even outside of the charging process - i.e. with battery power - if he deems this necessary in view of the battery condition, the temperature and the specific usage situation.

The invention is not limited in its implementation to the preferred embodiment given above. Instead, a number of variants are conceivable which make use of the solution presented even in fundamentally different embodiments.

AT044.G1 Sheet 13

In particular, the illustration in Fig. 4 is to be understood as an example only; the allocation of measuring devices to the battery groups or individual batteries can be varied in just as many ways as the control of the charging and heating processes as well as the driving operation.

Instead of a servo synchronous motor, an asynchronous motor can also be used to drive the vehicle, and the batteries can also be of a different type - such as nickel-cadmium batteries or, in principle, primary cells.

In addition to conventional accumulators, a device for electrochemical energy generation constructed in a completely different way from several components - such as chemical tanks and a reactor - can also be arranged distributed in a passenger car in accordance with the invention.

The division and exact spatial arrangement of the battery pack can also be varied according to the structural conditions of the original vehicle.

Claims (13)

I 1 AT044.G1 Sheet 14 Claims 1. Passenger car (1) with electric drive, with a drive motor (11), a plurality of batteries (41 to 46, 51 to 54, 71 to 74) for supplying power to the drive motor and a control unit (10) for the drive motor and the power supply, characterized in that the batteries (41 to 46, 51 to 54, 71 to 74) are arranged in at least two spatially separated groups (4, 5, 7) in the passenger car (1), wherein a first battery group (4) is arranged essentially in front of or above the front axle (3) in the engine compartment (2) and a second battery group (5) is arranged in front of the rear axle (6) below the interior of the passenger car. 2. Passenger car with electric drive, with a drive motor, a device comprising a plurality of components, in particular tanks and a reactor, for the electrochemical power supply of the drive motor and a control unit for the drive motor and the power supply, characterized in that the components are arranged spatially separated from each other in the passenger car, with a first component in the ATO44.G1 Sheet 15 essentially in front of or above the front axle in the engine compartment and a second component in front of the rear axle below the interior of the passenger car. 10 3. Passenger car according to claim 1 or 2, characterized in that the second battery group (5) or component essentially occupies the space in which the fuel tank is accommodated in a comparable passenger car with an internal combustion engine. 4. Passenger car according to one of the preceding claims, characterized in that a third battery group (7) or component is provided which is arranged essentially behind the rear axle (6) and occupies the space in which a spare wheel is accommodated in a comparable passenger car with an internal combustion engine. 5. Passenger car according to claim 1, 3 or 4, characterized in that the first battery group (4) comprises six lead-acid batteries (41 to 46) and the second and third battery groups (5, 7) each comprise at least four batteries (51 to 54 and 71 to 74, respectively), the batteries (51 to 54) of the second group (5) being arranged transversely to the longitudinal axis of the vehicle. 25 30 · AT044.G1 Sheet 16 6. Passenger car according to one of the preceding claims, characterized in that the individual battery groups (4, 5, 7) or components are each accommodated in a separate, essentially hermetically sealable container (40, 50, 70). 7. Passenger car according to one of the preceding claims, characterized in that a connection (9) which can be connected to an external power network and is connected to the control unit or at least one component for recharging the batteries or the device is accessible from the side of the passenger car (1), in particular instead of a tank nozzle present in a comparable passenger car with an internal combustion engine. 8. Passenger car according to claim 1 or one of claims 3 to 7, characterized in that the battery groups (4, 5, 7) are each assigned an electrical heating or cooling device (40g, 50g, 70g) by means of which the batteries can be optionally heated or cooled during charging. 9. Passenger car according to claim 6 or 7 and claim 8, characterized in that the electrical heating or cooling device of each battery group (4, 5, 7) comprises several heating or cooling elements (40g, 50g, 70g), each assigned to one of the batteries but controllable as a group, and a temperature sensor. AT044.G1 Sheet 17 10. Passenger car according to claim 8 or 9, characterized in that the heating device comprises heating foils (50g) which are in surface contact with the battery casing (53) - preferably on the underside of the batteries - and whose surface facing away from the battery casing has thermal insulation (50f). 11. Passenger car according to claim 6 or 7 and claim 10, characterized in that the containers are battery boxes (40, 50, 70) which have bases with central regions (50e) which are recessed relative to the edge regions and/or separate support ribs for the essentially load-free accommodation of the heating foil (50g) and the thermal insulation (50f) associated therewith. 12. Passenger car according to one of claims 8 to 11, characterized in that the electric heating or cooling device (40g, 50g, 70g) is connected to the control unit (10) and means for external temperature-dependent control during charging and means for optional start-up outside of charging times are provided. 13. Passenger car according to claim 1 or one of claims 3 to 12, characterized in that each battery group (4, 5, 7) has separate measuring devices (A4, U4, T4 or A5, U5, T5 or A7, U7, T7) for detecting the battery state and/or the temperature. ATO44.G1 Sheet door are assigned or assignable.