GB2607995A

GB2607995A - Road building machine, and method for operating the road building machine

Info

Publication number: GB2607995A
Application number: GB2205539.6A
Authority: GB
Inventors: Brammer Hauke
Original assignee: Dynapac GmbH
Current assignee: Dynapac GmbH
Priority date: 2021-04-14
Filing date: 2022-04-14
Publication date: 2022-12-21
Also published as: DE102021109293A1; GB202205539D0

Abstract

A road building machine 10 (e.g. road finisher, feeder or road miller) comprises: an electric motor as a primary drive assembly; and at least one electrical energy store/accumulator A1-A4 as an energy source for the drive assembly at least. The accumulator(s) is detachably connected to the road building machine and is provided as a replaceable energy store A2-A4, such that an accumulator which is no longer fully charged (i.e. discharged below a defined threshold value) can be replaced by a fully charged accumulator. Plural accumulators may be provided, which are replaceable individually or in combination. An integral accumulator A1 may remain on the road building machine even after being discharged, while a separate, discharged accumulator A2-A4 is replaced by fully charged replaceable accumulator. The integral accumulator may be charged by one or more of: the replaceable accumulators; an additional electrical energy source; or by a charger. A controller in the road building machine may control energy consumption of the accumulators, such that a replaceable accumulator is prioritised for consumption of electrical energy, and energy from the integral accumulator is provided only if some, or all, of the replaceable accumulators are discharged below a defined threshold value. The controller may control the energy consumption of all accumulators such that all are discharged uniformly.

Description

Road building machine, and method for operating the road building machine The invention relates to a road building machine according to the preamble of claim 1. Furthermore, the invention relates to a method according to claim 24 for operating a road building machine.

Road building machines, in particular road finishers, feeders, road millers or rollers, should as far as possible be able to be used for an entire working day without any or without significant interruption. In order to be able to meet these requirements for mobile road building machines comprising an electric motor as a primary drive, correspondingly large electrical energy stores are required. There is insufficient space to accommodate, on the road building machine, energy stores having sufficient capacity for an entire working day.

The object of the present invention is that of providing a road building machine comprising an electric motor as a primary drive assembly and at least one electrical energy store as an energy source at least for the drive assembly, such that the road building machine can be operated for an entire working day with as little operational interruption as possible.

A road building machine for solving this problem comprises the features of claim 1. The road building machine is characterised in that the energy store is releasably connected to the road building machine and is provided as a replaceable energy store, such that a replaceable energy store which is no longer fully charged can be replaced by a fully charged replaceable energy store. The proposed replaceability makes it possible for a virtually discharged replaceable energy store to be quickly replaced for a charged replaceable energy store. This can preferably take place at the respective whereabouts of the road building machine. The road building machine does not have to travel to a charging station. Only the removed replaceable energy store is transported to a charging station and charged there. In this way, the road building machine, in ongoing operation, only has to make a short break for replacing the replaceable energy store, not a charging break.

In connection with the invention, a road building machine is assumed which does not comprise an internal combustion engine as the primary drive, but rather in particular only an electric motor. The primary drive is preferably used for locomotion. Alternatively or in addition, the primary drive can indirectly or directly drive adjustment mechanisms, devices or tools. In this case, the primary drive can also serve as a drive for electromechanical, electropneumatic, or electrohydraulic energy conversion, in particular as a drive unit for a pump transfer gearbox.

The road building machine according to the invention is in particular a road finisher, a feeder, a road miller, or a roller. It can, however, also be a different type of road building machine comprising an electric motor as the primary drive.

According to the invention, a plurality of replaceable energy stores can be provided, which can be replaced individually or in combination. A plurality of smaller replaceable energy stores is easier to handle and transport.

According to the invention, it is furthermore possible for at least two energy stores to be provided, at least one energy store not being provided for replacement, and at least one energy store being provided as a replaceable energy store. The energy store not provided for replacement can also be arranged, in the road building machine, at a location that is difficult to access. As a result, the best possible use is made of the overall installation space of the road building machine available for the energy store.

According to the invention, a retainer and electrical connections for the energy store that is not provided for replacement can be formed such that said energy store is separable from the retainer and/or the connections only by means of a tool. The use of a tool for separating or releasing the retainer or the connections opposes simple and quick replacement of the energy store.

According to the invention, a retainer and electrical connections for the replaceable energy store can furthermore be formed such that the replaceable energy store is separable from the retainer and/or the connections without the use of tools. The retainer and connections should be releasable simply by hand, and without the use of a tool. In this connection, a security device, such as a lock with a key, is preferably not understood as a tool.

According to the invention, it is furthermore possible for a controller to be provided, at least for connecting or separating electrical connections between the energy store or the energy stores on the one hand, and electrical loads or an on-board power supply of the road building machine on the other hand. At least one electrical load is an electric motor as the primary drive assembly. In addition, further electrical loads may be provided, also within an on-board power supply. The energy store and load can be connected or electrically disconnected by means of the controller.

According to the invention, it is possible for the controller to prioritise a replaceable energy store for consumption of electrical energy, and to provide energy from an energy store not provided for replacement only if the replaceable energy store or a plurality of or all the replaceable energy stores are discharged to below a defined threshold value. The controller monitors the state of charge of the energy stores, including the replaceable energy stores, and optionally switches from the replaceable energy store to the energy store not provided for replacement. State of charge monitoring for energy stores is known in principle. Depending on the desired precision for the determination of the state of charge, different measuring methods are used. The simplest is detection of the voltage, in particular when no current is flowing. In addition, temperature, voltage curves, current curves, and further parameters, can be monitored and evaluated. Depending on the evaluated data, a value for the state of charge is determined, which is compared with a previously defined threshold value.

According to the invention, a charger or a connection for an external charger for charging at least one energy store may be provided, in particular a replaceable energy store and/or an energy store that is not provided for replacement. The structure of the road building machine and the control of the controller are simpler if only one connection for an external charger is provided. In contrast, an internal charger would have the advantage that merely a standardised power connector needs to be present at the location of use of the road building machine, if charging of the energy stores or disassembly thereof is intended to be carried out in work break for example.

According to the invention, an additional electrical energy source can be provided, in particular a fuel cell comprising a fuel store. The additional energy source is preferably provided for charging at least one energy store and/or for covering an electrical base load of the road building machine. A store for a liquid or gaseous medium, which is required for the fuel cell, is preferably arranged upstream of the fuel cell, on the road building machine.

According to the invention, a crane device for moving at least one energy store, in particular the replaceable energy store, may be provided. The crane device is a component of the road building machine and should in particular allow for lifting of an energy store out of a retainer, lateral shifting of the energy store to beyond a transport means located beside the road building machine or a charging station, deposition thereon, and a movement in the reverse direction. Energy stores can also be moved by means of the crane device, which energy stores are too heavy to be handled by operating personnel. The crane device is preferably electrically and/or hydraulically operated. The hydraulic energy is generated by means of the primary drive assembly.

According to the invention, an energy store can be provided with a receptacle for a pallet fork. The energy store is in particular provided on the bottom or top with openings for entry of the pallet fork. For this purpose, the energy store may comprise a correspondingly designed housing or frame, or an attachment. The pallet fork is preferably the fork of a forklift truck, in particular for handling standardised pallets, for example what are known as Euro pallets.

According to the invention, a retainer for at least one replaceable energy store can prevent a movement of the replaceable energy store in the horizontal direction. The retainer is preferably designed such that the replaceable energy store can be inserted into the retainer from above. In addition, a mechanical locking mechanism can be provided, which prevents a movement of the replaceable energy store in the vertical direction. The locking mechanism is preferably intended to be able to be unlocked without a tool. In this connection, a lock with a key is not considered a tool.

The replaceable energy store in particular has a mass of at most one ton. As a result, less powerful internal or external crane devices can also be used for handling the replaceable energy store.

According to the invention, further electrical loads, in particular electric motors, can be provided for moving adjustment mechanisms, devices or tools, or as a drive for energy converters. Energy converters are preferably of the electromechanical, electropneumatic or electrohydraulic type, for example electric motors with/without gears, compressors or hydraulic pumps. A fully or largely electrified variant is also possible, in which different electric motors directly drive various work functions.

According to the invention, it may be possible for a plurality of energy stores, or parts thereof, to be connected in parallel. These are in particular replaceable energy stores. It is also possible for energy stores not provided for replacement to be connected in parallel with replaceable energy stores. Preferably, all the energy stores are connected in parallel with one another. This makes it possible to temporarily or permanently restrict the energy supply for the primary drive assembly to one energy store, and for example to remove the further energy stores for charging.

Alternatively or in addition, the energy stores or parts thereof can be connected in series, in particular in order to form larger units having higher voltage.

According to the invention, electrical connections -for connecting one or more energy stores -can be designed in the form of plug connections, clamped connections, snap connections, rotary connections, or combinations thereof. In particular, the connections should be able to be released and connected without tools. Here, too, a lock with a key should not be considered a tool.

According to the invention, at least one energy store can be retained laterally on the road building machine, in particular the replaceable energy store or a plurality of replaceable energy stores. Preferably all the replaceable energy stores are retained laterally on the road building machine. On the one hand, the energy stores are easily accessible as a result, and on the other hand heat can be output at the surface of the energy store, by radiation. For example, a frame or chassis of the road building machine can comprise retainers for the energy stores.

According to the invention, at least one energy store can be retained on the road building machine so as to be accessible from above, in particular the replaceable energy store or a plurality of replaceable energy stores. The accessibility of the energy store is important in particular for the replacement thereof. Furthermore, servicing is more easily possible as a result, even in the case of an energy store that is not to be replaced.

According to the invention, at least one energy store can comprise a carrier device which can be received by a crane device, in particular the replaceable energy store or a plurality of replaceable energy stores. The carrier device and crane device are matched to one another, which is easily possible in particular in connection with an internal crane device.

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According to the invention, at least one energy store can be retained between the storage container and a control platform or between the storage container and the primary drive assembly, in particular the replaceable energy store or a plurality of replaceable energy stores. A road finisher, as the road building machine, comprises, at one end, a storage container which is also referred to as a bunker or trough. A screed is provided at the other end. A control platform is arranged above the screed. A space for arranging at least one energy store can be provided between the control platform and the storage container. The primary drive assembly can also be provided in this space, or for example below the control platform.

According to the invention, one or more galvanic elements or units consisting of a plurality of galvanic elements may be provided as the energy store. Galvanic elements as energy stores are tried and tested, economical, and available in all variations, as are units consisting of a plurality of galvanic elements.

According to the invention, the galvanic elements can be secondary cells or primary cells, and/or comprise solid or liquid electrolytes. Secondary cells are particularly long-lasting as rechargeable cells. Cells comprising solid electrolytes are particularly easy to handle. Cells comprising liquid electrolytes allow for a particularly quick charging process by means of exchange of the electrolytes.

According to the invention, electrostatic energy stores or capacitors as energy stores can be provided. Capacitors can take up and output electrical energy particularly quickly. In particular what are known as SuperCaps or HighCaps are provided as energy stores. The capacitors can also be combined to form one or more units.

According to the invention, a generator can be provided for recuperation of energy, in particular in conjunction with a wheeled chassis of the road building machine. Kinetic energy of the road building machine, in particular braking energy, can be converted into electrical energy by means of the generator. The generator feeds one or more of the electrical energy stores. In this connection, the road building machine is preferably a road finisher comprising a wheeled chassis. The generator can additionally be provided or be a functional component of a motor generator. The electric motor can then also run in generator operation.

The method according to the invention comprises the features of claim 24 and is in particular provided for operating a road building machine according to the invention.

According to the invention, a replaceable energy store which has been discharged to below a defined threshold value is replaced by a fully charged replaceable energy store. As a result, charging of the energy store on-site can be avoided. The road building machine does not have to travel to a charging station.

According to the invention, the method can furthermore provide for the road building machine to comprise at least two energy stores, and for at least one energy store thereof to remain on the road building machine and not be replaced even after being discharged, while a discharged replaceable energy store is replaced by a fully charged replaceable energy store. The energy store remaining on the road building machine can for example be discharged at the end of a working day, after the road building machine has travelled or been brought to the location of a charging station.

According to the invention, the energy store remaining on the road building machine can be charged by means of one or more replaceable energy stores, by an additional electrical energy source, or by a charger. Using replaceable energy stores or an additional electrical energy source makes it possible for the road building machine to remain at the location of use.

According to the invention, a controller in the road building machine can control the energy consumption of a plurality of energy stores such that a replaceable energy store is prioritised for consumption of electrical energy, and energy is provided from an energy store not provided for replacement only if the replaceable energy store or a plurality of or all the replaceable energy stores are discharged to below a defined threshold value.

Depending on the energy consumption during a working day, this makes it possible for only the replaceable energy stores to have to be replaced, without the road building machine having to be moved away from the location of use.

According to the invention, the controller in the road building machine can control the energy consumption of a plurality of energy stores, such that all or a plurality of the energy stores are discharged uniformly. As a result, deep discharge of individual energy stores can be prevented.

The energy stores of the road building machine are preferably monitored by a battery management system. The aim is in particular to identify the state of charge, the voltage, and the temperature, and also to acheive as long a service life as possible. Depending on

S

the technology of the energy stores, deep discharge, overcharging or overheating should be prevented.

The energy stores are components of an electrical system of the road building machine.

The electrical system preferably comprises inverters for adjusting the voltage of the energy stores at the electrical loads and/or when feeding electrical energy into the energy store, also in conjunction with optional recovery.

Further features of the invention can be found in the remainder of the description and in the claims. Advantageous embodiments of the invention will be explained in greater detail in the following, with reference to the drawings, in which: Fig. 1 is a side view of a conventional road building machine (prior art), specifically a road finisher, Fig. 2 is a schematic view of the road finisher according to Fig. 1, but in an embodiment according to the invention, Fig. 3 is a view from above of the road finisher according to Fig. 2, comprising a crane device, Fig. 4 is a schematic view of electrical components of a road building machine according to the invention.

A road building machine 10 as is shown in Fig. 1 is known for example from DE 10 2018 009 035 Al. This is a road finisher comprising a rear storage container 11, front screed 12, drive unit 13 in front of the storage container 11, control platform 14 in front of the drive unit 13 and above the screed 12, and a chassis 15. The road building machine is designed so as to be self-driving. For this purpose, the chassis 15 is driven by the drive unit 13. The drive unit 13 contains (not shown) an internal combustion engine as the primary drive assembly. All further loads inside the road building machine are also at least indirectly supplied with energy by the drive assembly. A region 16, inter alia comprising mechanical and hydraulic elements for moving the screed 12, is located between the screed 12 and the control platform 14.

In the embodiment according to the invention of Fig. 2, the drive unit 13 comprises an electric motor 17 as the primary drive assembly. In order to supply this with electrical energy, at least one replaceable accumulator A2, A3, A4, A5, A6 is provided as the energy store. In addition, in the embodiment of Fig. 2 an integral accumulator Al is arranged as a further energy store. Further integral accumulators or replaceable accumulators may be arranged on the road building machine.

In this case, the term "accumulator" is used for an energy store consisting of in particular a plurality of battery cells or accumulator cells, an energy store of this kind being commonly referred to as a battery, accumulator, or accumulator pack. For the purpose of simplification, only the designation accumulator is used here. Instead of the accumulators Al to A6, or in addition, it is of course also possibel for other, in particular charageable, electrical energy stores to be provided.

The replaceable accumulators A2 to A4 are preferably arranged such that a replacement is possible with as little outlay as possible. According to Fig. 2, the replaceable accumulators A2 to A4 are in each case accessible from above and may comprise carrier devices (not shown), by means of which it is possible to easily grasp and raise the replaceable accumulators. In this case, the replaceable accumulators A2, A3 are perpendicular, while the replaceable accumulator A4 is retained in a horizontal plane. In contrast, the integral accumulator Al may be arranged so as to be more difficult to access, i.e. in Fig. 2 below the electric motor 17.

As is clear in Fig. 3, alternatively or in addition the replaceable accumulators A5, A6 may also be arranged laterally on the road building machine 10, also shown upright here.

The accumulators Al to AS may also be designed so as to be significantly larger, and may be retained at a different location on the road building machine from that shown in Fig. 2 and 3. A preferred design and arrangement of all the accumulators is one in which they do not furthermore protrude laterally beyond the silhouette of the road building machine.

For handling the replaceable accumulators A2 to A6, the road building machine 10 may comprise a crane device 18, see Fig. 3. In this case, the crane device 18 is arranged on the edge of or adjacently to the control platform 14, and simultaneously adjacent to the drive unit 13, and comprises a boom 19 which is at least pivotable (arrow 20) and telescopic (arrow 21). A retractable and extendible support cable (not shown) can be retained on the boom 19. Alternatively, at least one free end 22 of the boom 19 can be raised and lowered, with a vertical movement component, i.e. perpendicularly to the image plane of Fig. 3.

Fig. 4 shows a simplified electrical circuit comprising the accumulators Al, A2, A3 that are connected in parallel with one another, and the electric motor 17. An electronic controller EC, a fuel cell BZ that is connected in parallel with the accumulators and comprises a fuel supply (not shown), and a charger LG, are furthermore visible. The electric motor 17 is connected to the accumulators Al, A2, A3, the fuel cell BZ, and the charger LG, by means of a main line 23 and stubs 24, 25, 26, 27, 28, 29.

All the stubs 24 to 29 are provided with relays 30, 31, 32, 33, 34, 35 which can be actuated by the electronic controller EC. Means for fine control of the electric motor 17 may be provided in the region of the relay 30 or at another location, for example for reversing the direction of rotation, for speed control, or for torque control.

The accumulators Al to AS can be switched to the main line 23 individually or in combination, by means of the electronic controller EC. The fuel cell BZ can also be connected. In this way, individual accumulators can be purposely selected for current supply, depending on the power requirement. Furthermore, the fuel cell BZ comprising the fuel supply (not shown) can be used as an additional energy source for the electric motor or for charging the accumulators Al to A3. The additional relay (not shown) along the main line 23 also makes combined operation possible, for example charging the accumulator AS by means of the fuel cell, and simultaneously supplying the electric motor 17 from the accumulator Al.

The charger LG is connected to a socket 36 for connection to a charging cable (not shown). In addition or alternatively to the charger LG, a socket 38 can be connected to the relay 35 by means of a stub 37, specifically for connection of an external charger.

In Fig. 4, too, the accumulator Al is preferably an integral accumulator, while the further accumulators A2, A3 are replaceable accumulators. The fuel cell BZ can be associated with a store (not shown) for a fuel. The fuel cell BZ and/or the store are preferably also arranged either in the region of the drive unit 13 and/or laterally on the road building machine 10.

The electronic controller EC is connected to the measuring devices M1 to M4 on the accumulators Al to A3 and the fuel cell BZ. The measuring devices M1 to M4 record variable characteristic for the accumulators Al to AS and the fuel cell BZ, in particular for determining the state of charge or a remaining capacity. Voltage, current and temperature are preferably recorded, and transmitted to the electronic controller EC. For example, the states of charge can be calculated or estimated in the electronic controller EC, from the current values and/or the temporal progression.

A display device 39 is connected to the electronic controller EC, by means of which individual states of charge and signals can be displayed to the operating personnel. The electronic controller EC can for example be programmed such that, initially, for example at the start of a working day, only the replaceable accumulator A3 is switched onto the main line 23, and the electric motor 17 is supplied with electrical energy. As soon as the state of charge or the remaining capacity of the replaceable accumulator A3 fall below a previously defined threshold value, the relay 33 switches off the stub 27 and the replaceable accumulator A2 is switched onto the main line 23. At the same time, the display device 39 shows that the replaceable accumulator A3 is to be replaced. The replacement is made at the next opportunity.

As long as no replacement has taken place, the electric motor 17 is supplied from the replaceable accumulator A2. As soon as the state of charge or the remaining capacity thereof drop below the threshold value, the relay 32 disconnects the stub 26 and the integral accumulator Al is switched onto the main line 23. The required replacement of the accumulator A2 is displayed on the display device 39. In work breaks or at the end of a working day, the accumulators Al to A3 can be charged from the fuel cell BZ and/or from the charger LO or the socket 38.

Operation having all or a plurality of connected accumulators Al to AS is also possible, optionally also in conjunction with the fuel cell BZ, if there is a particularly high power requirement. The fuel cell BZ is supplied from a fuel supply (not shown) of the road building machine 10.

In addition to the drive motor 17, further electrical loads may be provided, shown in a simplified manner in Fig. 4 by the load 40. Said load is preferably also connected to the main line 23 by a stub 41, and can be connected in by means of a relay 42. Here, too, additional means for fine control may be provided in the region of the relay 42 or at another location. The load 40 is preferably an electrical drive, also in conjunction with an energy converter, in particular for moving adjustment mechanisms, devices or tools of the road building machine 10.

The embodiments explained with reference to the drawings relate in particular to a road finisher as a road building machine. The road building machine can alternatively also be a feeder, a road miller, a roller, or another road building machine.

List of reference signs: road building machine Al integral accumulator 11 storage container A2 replaceable accumulator 12 screed A3 replaceable accumulator 13 drive unit A4 replaceable accumulator 14 control platform AS replaceable accumulator chassis AS replaceable accumulator 16 region BZ fuel cell 17 electric motor EC electronic controller 18 crane device LG charger 19 boom M1 measuring device arrow M2 measuring device 21 arrow M3 measuring device 22 free end M4 measuring device 23 main line 24 stub stub 26 stub 27 stub 28 stub 29 stub relay 31 relay 32 relay 33 relay 34 relay relay 36 socket 37 stub 38 socket 39 display device electrical load 41 stub 42 relay

Claims

Claims: 1. Road building machine (10), in particular road finisher, feeder or road miller, comprising an electric motor (17) as the primary drive assembly, and comprising at least one electrical energy store (Al to A6) as an energy source at least for the drive assembly, characterised in that the energy store (Al to A6) is detachably connected to the road building machine (10) and is provided as a replaceable energy store (A2 to A6), such that a replaceable energy store (A2 to A6) which is no longer fully charged can be replaced by a fully charged replaceable energy store.
2. Road building machine (10) according to claim 1, characterised in that a plurality of replaceable energy stores (A2 to A6) is provided, which are replaceable individually or in combination.
3. Road building machine (10) according to either claim 1 or claim 2, characterised in that at least two energy stores (Al, A2 to A6) are provided, at least one energy store (Al) not being provided for replacement, and at least one energy store (A2 to A6) being provided as a replaceable energy store.
4. Road building machine (10) according to claim 3, characterised by a retainer and electrical connections for the energy store (1) that is not provided for replacement, said energy store (Al) being separable from the retainer or the connections only by means of a tool.
5. Road building machine (10) according to any of claims 1 to 4, characterised by a retainer and electrical connections for the replaceable energy store (A2 to A6), the replaceable energy store (A2 to A6) being separable from the retainer and the connections without the use of tools.
S. Road building machine (10) according to any of claims 1 to 5, characterised by a controller (EC) at least for connecting or separating electrical connections between the energy store or the energy stores (Al to A6) on the one hand, and electrical loads (17) or an on-board power supply (23) of the road building machine (10) on the other hand.
7. Road building machine (10) according to claim 6, characterised in that the controller (EC) prioritises a replaceable energy store (A2 to A6) for the consumption of electrical energy, and provides energy from an energy store (Al) not provided for replacement only if the replaceable energy store (A2 to A6) or a plurality of or all the replaceable energy stores are discharged to below a defined threshold value.
8. Road building machine (10) according to any of claims 1 to 7, characterised by a charger (LG) or a connection (38) for an external charger for charging at least one energy store (Al to A6), in particular a replaceable energy store (A2 to A6) and/or an energy store (Al) that is not provided for replacement.
9. Road building machine (10) according to any of claims 1 to 8, characterised by an additional electrical energy source, in particular a fuel cell (BZ) comprising a fuel store.
10. Road building machine (10) according to any of claims 1 to 9, characterised by a crane device (18) for moving at least one energy store, in particular the replaceable energy store (A2 to A6).
11. Road building machine (10) according to any of claims 1 to 10, characterised by an energy store (A2 to A6) comprising a receptacle for a pallet fork.
12. Road building machine (10) according to any of claims 1 to 11, characterised by a retainer for at least one replaceable energy store (A2 to A6), the retainer preventing a movement of the replaceable energy store (A2 to A6) in the horizontal direction.
13. Road building machine (10) according to any of claims 1 to 12, characterised by further electrical loads (40), in particular electric motors, for moving adjustment mechanisms, devices or tools, or as a drive for energy converters.
14. Road building machine (10) according to any of claims 1 to 13, characterised in that a plurality of energy stores (Al to A6) or parts thereof are connected in parallel.
15. Road building machine (10) according to any of claims 1 to 14, characterised in that electrical connections are provided for connecting one or more energy stores (Al to A6), the electrical connections being designed in the form of plug connections, clamped connections, snap connections, rotary connections, or combinations thereof.
16. Road building machine (10) according to any of claims 1 to 15, characterised in that at least one energy store (A5, A6) is retained laterally on the road building machine (10), in particular the replaceable energy store or a plurality of replaceable energy stores.
17. Road building machine (10) according to any of claims 1 to 16, characterised in that at least one energy store (A2 to A4) is retained on the road building machine (10) so as to be accessible from above, in particular the replaceable energy store or a plurality of replaceable energy stores.
18. Road building machine (10) according to any of claims 1 to 17, characterised in that at least one energy store (A2 to A6) comprises a carrier device which can be received by a crane device (18), in particular the replaceable energy store (A2 to A6) or a plurality of replaceable energy stores.
19. Road building machine (10) according to any of claims 1 to 18, characterised in that at least one energy store (Al to A6) is retained between the storage container (11) and a control platform (14) or between the storage container (11) and the primary drive assembly (17), in particular the replaceable energy store (A2 to A6) or a plurality of replaceable energy stores.
20. Road building machine (10) according to any of claims 1 to 19, characterised in that one or more galvanic elements or units consisting of a plurality of galvanic elements are provided as the energy store (Al to A6).
21. Road building machine (10) according to claim 20, characterised in that the galvanic elements are secondary cells or primary cells, and/or comprise solid or liquid electrolytes.
22. Road building machine (10) according to any of claims 1 to 21, characterised in that electrostatic energy stores are provided.
23. Road building machine (10) according to any of claims 1 to 22, characterised by a generator for recovering energy, in particular in conjunction with a road finisher comprising a wheeled chassis as the road building machine.
24. Method for operating a road building machine (10), in particular road finisher, feeder or road miller, comprising an electric motor (17) as the primary drive assembly, and comprising at least one energy store (Al to A6) as an energy source for the drive assembly, in particular for operating a road building machine (10) according to claim 1 or any of the further claims, characterised in that a replaceable energy store (A2 to A6) which is discharged to below a defined threshold value is replaced by a fully charged replaceable energy store.
25. Method according to claim 24, characterised in that at least two energy stores are provided, and in that at least one energy store (Al) thereof remains on the road building machine (10) and is not replaced even after being discharged, while a discharged replaceable energy store (A2 to A6) is replaced by a fully charged replaceable energy store.
26. Method according to claim 25, characterised in that the energy store (Al) remaining on the road building machine (10) is charged by means of one or more replaceable energy stores (A2 to A6), by an additional electrical energy source (BZ, 38), or by a charger (LG).
27. Method according to any of claims 24 to 26, characterised in that a controller (EC) in the road building machine (10) controls the energy consumption of a plurality of energy stores, such that a replaceable energy store (A2 to A6) is prioritised for consumption of electrical energy, and energy from an energy store (Al) not provided for replacement is provided only if the replaceable energy store (A2 to A6) or a plurality of or all the replaceable energy stores are discharged to below a defined threshold value.
28. Method according to any of claims 24 to 27, characterised in that a controller (EC) in the road building machine (10) controls the energy consumption of a plurality of energy stores (Al to A6), such that all or a plurality of the energy stores are discharged uniformly.