Method for producing a battery tray for receiving an energy supply unit for a mobile work machine, associated filling device for carrying out the method, and lithium-ion traction battery

Abstract

The invention relates to a method for producing a battery tray (2) for receiving an energy supply unit, in particular at least one lithium-ion battery module, for a mobile work machine, in particular an industrial truck, wherein the battery tray (2) is at least partly filled with a ballast material (3), the battery tray (2) has an outer shell (6) with an outer wall (5), and the ballast material (3) is filled into the battery tray (2) in a filling process. The ballast material (3) is sprayed with a composite material (15) during the filling process.

Description

[0001] 24322 / P24024-DEa / KBS= EM-KBS001

[0002] February 13, 2025 - Geirhos

[0003] 1

[0004] Description

[0005] Method for manufacturing a battery tray for housing a power supply unit for a mobile work machine

[0006] The invention relates to a method for manufacturing a battery tray for receiving a power supply unit, in particular at least one lithium-ion battery module, for a mobile working machine, in particular a forklift truck, wherein the battery tray is at least partially filled with a ballast material, wherein the battery tray has an outer shell with an outer wall, and wherein the ballast material is filled into the battery tray in a filling process.

[0007] A mobile work machine powered by a battery-electric drive, in particular a battery-electric industrial truck, for example a battery-electric counterbalance forklift, has a traction battery to provide the electrical drive energy. The traction battery has a battery tray in which one or more battery modules are installed. In known battery-electric industrial trucks, the traction battery is usually designed to be replaceable, so that a discharged traction battery can be easily replaced with a charged one during operation of the industrial truck.

[0008] Electrically powered industrial trucks, such as counterbalance forklifts, have a lifting mast with a load-handling device, such as a fork, on the front axle. The stability of such trucks with a load is crucially determined by the vehicle's overall center of gravity, which in turn depends on the position of the counterweight, as well as the position and weight of the traction battery.

[0009] Conventional traction batteries are relatively heavy lead-acid batteries that contribute significantly to the counter-torque against a load in the industrial truck. To prevent unstable conditions and the risk of a 24322 / P24024-DEa / KBS= EM-KBS001

[0010] February 13, 2025 - Geirhos

[0011] 2

[0012] To prevent the forklift from tipping over, the vehicle weight and center of gravity are also important when braking.

[0013] Newer technologies now allow for the production and industrial use of batteries and accumulators that offer improved performance. These batteries can be described as high-performance batteries, characterized by a higher energy density relative to weight and / or volume compared to lead-acid batteries, and by the use of a different energy storage technology than a lead-acid reaction. Many high-performance batteries also feature the ability to deliver high power during discharge and / or charge at high power. The typical energy densities relative to weight and / or volume of a high-performance battery are higher than, and outside the range of, the corresponding parameters for lead-acid batteries, at least for one of these two values.

[0014] Lithium-ion batteries, which have achieved a level of reliability suitable for mass production, are increasingly being used on a larger scale than such high-performance batteries. They are characterized by high energy density, have only a low memory effect, and allow for high-power discharge and charging of the battery.

[0015] The use of such high-performance batteries is particularly advantageous in mobile machinery, for example industrial trucks, as traction batteries, because due to the high energy density in relation to the volume, a larger amount of electrical energy can be stored in the given installation space for the traction battery, thus increasing the range of a vehicle or the operating time of the industrial truck.

[0016] However, in battery-electric industrial trucks where a lithium-ion traction battery is used as a high-performance battery, with lithium-ion battery modules installed in the battery tray, the disadvantage arises that the lower weight of the lithium-ion traction battery compared to a lead-acid traction battery (with lead-acid battery modules installed in the battery tray) affects the center of gravity of the entire industrial truck. 24322 / P24024-DEa / KBS= EM-KBS001

[0017] February 13, 2025 - Geirhos

[0018] 3 and thus the stability and load-bearing capacity of the industrial truck is changed.

[0019] Therefore, there is a need to align the weight of a lithium-ion traction battery with the weight of a lead-acid traction battery with the same external dimensions of the battery tray, so that a lead-acid traction battery can be replaced by a lithium-ion traction battery in the industrial truck without affecting the load-bearing capacity and stability of the industrial truck.

[0020] It is known from DE 10 2014 106 644 B4 to attach a plate-shaped additional weight to the outside of the battery tray of a lithium-ion traction battery of a forklift truck, using fasteners, in order to equalize the weight of the lithium-ion traction battery with that of a lead-acid traction battery with the same size battery tray. However, such a plate-shaped additional weight and the required fasteners result in a high degree of construction complexity.

[0021] To increase the weight of a lithium-ion traction battery for a mobile work machine, it is also possible to partially fill the battery tray of the traction battery with ballast material. In the first process step of manufacturing the battery tray, a mixture of metal parts and a composite material is produced as ballast material, and in a second process step following the first, the mixture of metal parts and composite material is then filled into the battery tray and hardens into a composite material within the battery tray.

[0022] However, a disadvantage of this method is that producing the mixture of metal parts and composite material during the battery tray manufacturing process is an additional step prior to the second step of filling the tray. This step requires additional processing time, and a mixing device, such as a mixing machine, is necessary to produce the mixture. Furthermore, the mixing device leads to increased maintenance and cleaning requirements. Another disadvantage is that producing the mixture of metal parts and composite material requires a large quantity of composite material. 24322 / P24024-DEa / KBS= EM-KBS001

[0023] February 13, 2025 - Geirhos

[0024] 4

[0025] The present invention is based on the objective of providing a method for manufacturing a battery tray of the type mentioned at the outset, which is improved with regard to the aforementioned disadvantages.

[0026] This problem is solved according to the invention by a method for manufacturing a battery trough for receiving an energy supply unit, in particular at least one lithium-ion battery module, for a mobile working machine, in particular a forklift truck, wherein the battery trough is at least partially filled with a ballast material, wherein the battery trough has an outer shell with an outer wall, wherein the ballast material is filled into the battery trough in a filling process, and the ballast material is sprayed with a composite material during the filling process.

[0027] In the method according to the invention, the ballast material is sprayed with the composite material during the filling process, i.e., while being poured into the battery tray and thus while the battery tray is being filled. Spraying the ballast material with the composite material during the filling process allows for a uniform coating of the ballast material with the composite material to be achieved simply and without additional process time. This offers advantages because no prior mixing process is required to produce a mixture of metal parts and composite material, and no mixing device is needed to produce the mixture consisting of the metal parts and the composite material, thus also avoiding the maintenance and cleaning costs associated with such a device.Furthermore, it has been shown that by spraying the ballast material during the filling process, the amount of composite material required can be significantly reduced compared to producing a mixture of metal parts and composite material in a mixing device.

[0028] According to an advantageous embodiment of the invention, the ballast material is filled into the battery trough from an outlet opening of a filling device during the filling process, and is sprayed with the composite material during its free fall. Thus, the ballast material is sprayed with the composite material after leaving the outlet opening of the filling device and before impacting the battery trough, so that a mixture of ballast material and composite material is provided in a simple manner and without an additional mixing device. 24322 / P24024-DEa / KBS= EM-KBS001

[0029] February 13, 2025 - Geirhos

[0030] 5

[0031] According to an advantageous embodiment of the invention, the ballast material sprayed with the composite material hardens into a composite material within the battery tray. After hardening, the composite material exists as a solid body within the battery tray. This hardening into a composite material offers further advantages, as the hardened composite material results in high stiffness, high impact resistance, and high stability of the battery tray.

[0032] According to an advantageous embodiment of the invention, the composite material comprises 99.5–95% by weight of ballast material and 0.5–5% by weight of composite material. Preferably, the composite material comprises 99–97% by weight of ballast material and 1–3% by weight of composite material.

[0033] Particularly preferably, the composite material comprises 98.5–97.5% by weight of ballast material and 1.5–2.5% by weight of composite material. It has been shown that with this percentage of composite material, which is sprayed onto the ballast material being filled into the battery tray during filling, sufficient wetting of the ballast material can be achieved, which then hardens into a solid composite material after filling into the battery tray.

[0034] According to an advantageous embodiment of the invention, the ballast material is sprayed with resin, in particular synthetic resin, as a composite material. The resin is preferably in a liquid state, so that it can be easily sprayed onto the ballast material using a suitable spraying device. Suitable resins include common types such as epoxy resin or polyester resin, which can be in the form of a one-component or multi-component resin.

[0035] According to an advantageous embodiment of the invention, metal parts and / or slag are filled into the battery trough as ballast material. Preferably, scrap metal, steel scrap, or iron scrap is used as the metal parts, which can be crushed to a desired size before being filled into the battery trough. Alternatively or additionally, slag from the steel industry, in particular slag from iron or steel production, so-called blast furnace slag or steelworks slag, can be used as ballast material, which can be in the form of slag material crushed to a desired size, in particular fine-grained granules. 24322 / P24024-DEa / KBS= EM-KBS001

[0036] February 13, 2025 - Geirhos

[0037] 6

[0038] Spraying crushed metal parts and / or crushed slag material with the compound when filling the battery trough offers further advantages, as spraying with the compound ensures reliable wetting of the crushed metal parts or crushed slag material and eliminates the need for time-consuming cleaning of the metal parts or slag material, which may be contaminated with impurities such as oil, coolant, paint and / or oxidation.

[0039] According to an advantageous embodiment of the invention, the amount of composite material sprayed onto the ballast material during the filling process is varied. This allows the mixing ratio of ballast material and composite material to be easily adjusted, for example, to the quantity and / or composition and / or size of the ballast material and / or its properties, such as the amount of impurities.

[0040] The invention further relates to a filling device for carrying out the above-mentioned method.

[0041] The above-mentioned problem is solved with regard to the filling device by the fact that the filling device has a filling device which has an outlet opening and a spray device which is arranged in a vertical direction below the outlet opening.

[0042] During the filling process, the ballast material is poured by free fall from the outlet opening of the filling device into the outer shell of the battery trough. A spray device positioned vertically below the outlet opening allows the ballast material falling into the battery trough to be easily and safely sprayed with the composite material during the filling process.

[0043] According to an advantageous embodiment of the invention, the filling device can be designed as a storage container, for example a silo, or as a conveyor belt. In the case of a conveyor belt, the discharge point where the ballast material leaves the conveyor belt forms the discharge opening. 24322 / P24024-DEa / KBS= EM-KBS001

[0044] February 13, 2025 - Geirhos

[0045] 7

[0046] According to an advantageous embodiment of the invention, the spraying device comprises at least two spray devices arranged in the circumferential direction of a ballast material stream falling from the outlet opening, in particular in a uniformly distributed manner. The ballast material falls freely from the outlet opening of the filling device, and if the ballast material consists of metal parts, these metal parts form a ballast material stream. With several spray devices arranged in the circumferential direction of the ballast material stream falling from the outlet opening, in particular in a uniformly distributed manner, uniform wetting of the metal parts can be achieved simply.

[0047] According to an advantageous embodiment of the invention, the spraying device includes a valve assembly configured to control or regulate the amount of composite material sprayed onto the ballast material. The valve assembly is preferably arranged in a supply line of the spraying device. Preferably, the valve assembly is controlled by an electronic control unit of the filling device, thereby enabling a high degree of automation of the filling device.

[0048] The invention further relates to a lithium-ion traction battery for a mobile working machine, in particular a forklift truck, using a battery trough produced according to the invention, wherein at least one lithium-ion battery module is installed in the battery trough filled with the ballast material.

[0049] The invention offers a number of advantages.

[0050] The invention achieves a reduction in the requirement and thus the quantity of composite material compared to upstream mixing and the production of a mixture of ballast material and composite material in a mixing device.

[0051] The invention reduces the process time in the manufacture of the battery tray because filling the battery tray with ballast material and wetting the ballast material with the composite material occur in parallel and thus simultaneously within the process. 24322 / P24024-DEa / KBS= EM-KBS001 13.02.2025 - Geirhos

[0052] 8

[0053] The invention offers reduced maintenance compared to upstream mixing and the production of a mixture of ballast material and composite material in a mixing device, since no mixing device is required and thus the maintenance and cleaning of an upstream mixing device is eliminated.

[0054] The invention enables rapid adjustment of the mixing ratio of composite material and ballast material and allows for a high degree of automation of the overall process.

[0055] Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiment shown in the schematic figures. Here,

[0056] Figure 1 shows a schematic representation of a filling device for carrying out the method according to the invention and

[0057] Figure 2 shows a block diagram of the method according to the invention.

[0058] Figure 1 shows a filling device 1 for carrying out the method according to the invention, with which a battery tray 2 for receiving a power supply unit for a mobile work machine, in particular a forklift truck, is produced. The battery tray 2 is at least partially filled with a ballast material 3 to increase its weight.

[0059] The battery trough 2 has an outer shell 6 with an outer wall 5. In Figure 1, the battery trough 2 is shown in a longitudinal section. The outer wall 5 comprises a left outer wall 5a, a right outer wall 5b, a front wall located at the front in the plane of the drawing (not shown in detail in Figure 1), and a rear wall located at the rear in the plane of the drawing (not shown in detail in Figure 1).

[0060] In the illustrated embodiment, the battery trough 2 is provided with an intermediate floor 9, which is connected to the outer walls 5a, 5b, the front wall and the rear wall. The intermediate floor 9 divides the outer shell 6 and thus the interior of the battery trough 2 into a ballast compartment 7, which is filled with the ballast material 3, and a receiving compartment 8, in which, after filling with the 24322 / P24024-DEa / KBS= EM-KBS001

[0061] February 13, 2025 - Geirhos

[0062] 9

[0063] Ballast space 7 with ballast material 3 battery modules, in particular lithium-ion battery modules, can be installed.

[0064] The battery tray 2 is preferably formed from sheets, in particular steel sheets.

[0065] The filling device 1 has a filling device 10 which has an outlet opening 11 and a spray device 12 which is arranged in a vertical direction V below the outlet opening 11.

[0066] The filling device 10 is filled with the ballast material 3. The ballast material 3 preferably consists of crushed metal parts. Metal scrap, specifically steel scrap or iron scrap, is preferably used as the metal parts and can be crushed to a desired size before being filled into the battery trough 2. Alternatively or additionally, slag from the steel industry, in particular slag from iron or steel production, so-called blast furnace slag or steelworks slag, can be used as ballast material 3. This slag material can be in the form of slag material crushed to a desired size, especially fine-grained granules.

[0067] To fill the battery trough 2 with the ballast material 3, the battery trough 2 is positioned vertically V below the outlet opening 11 of the filling device 10, so that after opening the outlet opening 11 in a filling process the ballast material 3 falls in free fall from a defined height into the ballast space 7 of the battery trough 2.

[0068] The spraying device 12 is designed to spray the ballast material 3 during the filling process of the battery trough 2 with a composite material 15. This means that the ballast material 3 falling from the filling device 10 into the battery trough 2 during this process is sprayed with the composite material 15. The spraying device 12 thus sprays the ballast material 3 falling from the filling device 10 with the composite material 15 before it enters the battery trough 2. The spraying device 12 is preferably designed such that the ballast material 3 falling into the battery trough 2, for example, the metal parts and / or the crushed slag material, is uniformly wetted with the composite material 15. 24322 / P24024-DEa / KBS= EM-KBS001

[0069] February 13, 2025 - Geirhos

[0070] 10

[0071] A resin, in particular a synthetic resin, is preferably used as the composite material. The resin is preferably in a liquid state, so that it can be easily sprayed onto the material from the filling device by means of a suitable spraying device 12.

[0072] Ballast material 3 falling into battery tray 2 can be sprayed on. Suitable resins include common types such as epoxy resin or polyester resin, which can be available as a one-component or multi-component resin.

[0073] The spraying device 12 can comprise at least two spray devices 12a, 12b, which are arranged in the circumferential direction of a ballast material stream falling from the outlet opening 11, in particular in a uniformly distributed manner. In the embodiment shown in Figure 1, two spray devices 12a, 12b are provided, which are arranged opposite each other.

[0074] The spray device 12 can include a valve device 20 configured to control or regulate the amount of composite material 15 sprayed onto the ballast material 3. In the illustrated embodiment, the valve device 20 comprises two valves 20a and 20b, with valve 20a being arranged in a supply line 21a that carries the composite material to the first spray device 12a, and valve 20b being arranged in a supply line 21b that carries the composite material to the second spray device 12b. The valve device 20 is preferably controlled by an electronic control unit of the filling device 1, which controls the filling process of the battery trough 2 with ballast material 3.

[0075] To produce the battery trough 2 filled with ballast material 3, the ballast material 3 is sprayed with a composite material 15 by means of the spray device 12 during the filling process in which the ballast material 3 is filled into the battery trough 2.

[0076] The ballast material 3 is removed from the outlet opening during the filling process.

[0077] The material 11 of the filling device 10 is filled in free fall into the outer shell 6 of the battery trough 2 and, by means of the spray device 12, which is arranged in a vertical direction V below the outlet opening 11, is sprayed with the composite material 15 during free fall from the outlet opening 11 into the battery trough 2 and thus before impact in the battery trough 2. 24322 / P24024-DEa / KBS= EM-KBS001

[0078] February 13, 2025 - Geirhos

[0079] 11

[0080] In the vertical direction V below the spray device 12, ballast material 3a, sprayed with and thus wetted with the composite material 15, is present, which falls into the battery trough 2 and disposes of the battery trough 2.

[0081] The ballast material 3, sprayed with the composite material 15, hardens into a composite material in the battery trough 2. After hardening, the composite material exists as a solid body in the battery trough 2. The hardened composite material represents additional weight and results in high stiffness, high impact resistance, and high mechanical stability of the battery trough 2, whereby the outer wall 5 of the battery trough 2 can be made of thin-walled steel sheets.

[0082] After the composite material has hardened, the battery tray 2 can be used for the production of a lithium-ion traction battery for a mobile working machine, in particular a forklift truck, wherein at least one lithium-ion battery module is installed in the receiving space 8 of the battery tray.

[0083] The mass of the ballast filling formed by the ballast material 3 filled into the battery tray 2 is preferably selected such that the weight of the battery tray 2 according to the invention, which is provided with the ballast filling and in which lithium-ion battery modules are installed, is adapted and aligned with the weight of a lithium-ion traction battery having the same external dimensions of the battery tray 2, so that in a forklift truck a replacement of a lead-acid traction battery by a lithium-ion traction battery which is provided with the battery tray 2 made according to the invention is made possible without impairing the load-bearing capacity and stability of the forklift truck.

[0084] Figure 2 shows a block diagram of the method according to the invention.

[0085] In a first step S1, ballast material 3 is provided in the filling device 1 and composite material 15 is provided at the spraying device 12.

[0086] In a subsequent second step S2, the battery tray 2 is positioned vertically V below the outlet opening 11 of the filling device 1. 24322 / P24024-DEa / KBS= EM-KBS001 13.02.2025 - Geirhos

[0087] 12

[0088] In a subsequent third step S3, a filling process is carried out in which the ballast material 3 is filled into the battery tray 2 and sprayed with the composite material 15 during the filling process. In the third step S3, the ballast material 3 is filled from the outlet opening 11 of the filling device 1 into the outer shell 6 of the battery tray 2 in free fall and is sprayed with the composite material 15 by the spray device 12 during free fall.

[0089] In a subsequent fourth step S4, the ballast material 3 sprayed with the composite material 15 is hardened in the battery trough 2 to form a solid composite material.

[0090] In a subsequent fifth step S5, one or more lithium-ion battery modules can be installed in the battery trough 2 to produce a lithium-ion traction battery for a mobile working machine, in particular a forklift truck.

[0091] Between the third step S3 and the fourth step S4, the ballast material 3, which has been filled into the battery trough 2 and sprayed with the composite material 15, can optionally be compacted. To compact the ballast material 3, the battery trough 2 filled with the ballast material 3 can be vibrated. For the vibration process, the ballast material 3 filled into the battery trough 2 can be shaken using a vibrator. Preferably, the battery trough 2 filled with the ballast material 3 is vibrated using a vibrating plate on which the battery trough 2 rests. By vibrating the battery trough 2 filled with the ballast material 3, a flat and even surface of the ballast material 3 filled into the battery trough 2 can be easily achieved before hardening.

Claims

24322 / P24024-DEa / KBS= EM-KBS001 02 / 13 / 2025 - Geirhos 13 Patent claims 1. Method for manufacturing a battery tray (2) for receiving a power supply unit, in particular at least one lithium-ion battery module, for a mobile working machine, in particular a forklift truck, wherein the battery tray (2) is at least partially filled with a ballast material (3), wherein the battery tray (2) has an outer shell (6) with an outer wall (5), wherein the ballast material (3) is filled into the battery tray (2) in a filling process, characterized in that the ballast material (3) is sprayed with a composite material (15) during the filling process.

2. Method according to claim 1, characterized in that the ballast material (3) is filled into the battery trough (2) by free fall from an outlet opening (11) of a filling device (10) during the filling process and is sprayed with the composite material (15) during the free fall.

3. Method according to claim 1 or 2, characterized in that the ballast material (3) sprayed with the composite material (15) hardens into a composite material in the battery trough (2).

4. Method according to claim 3, characterized in that the composite material comprises 99.5 - 95 weight percent ballast material (3) and 0.5 - 5 weight percent composite material (15).

5. Method according to one of claims 1 to 4, characterized in that the ballast material (3) is sprayed with resin, in particular synthetic resin, as a composite material (15).

6. Method according to one of claims 1 to 5, characterized in that metal parts and / or slag are filled into the battery trough (2) as ballast material (3). 24322 / P24024-DEa / KBS= EM-KBS001 February 13, 2025 - Geirhos 14 7. Method according to one of claims 1 to 6, characterized in that the amount of composite material (15) which is sprayed onto the ballast material (3) during the filling process is changed.

8. Filling device (1) for carrying out the method according to one of claims 1 to 7, characterized in that the filling device (1) has a filling device (10) which has an outlet opening (11) and a spray device (12) which is arranged in a vertical direction (V) below the outlet opening (11).

9. Filling device according to claim 8, characterized in that the spraying device (12) comprises at least two spraying devices (12a, 12b) which are arranged in the circumferential direction of a ballast material stream falling from the outlet opening (11), in particular in a uniformly distributed manner.

10. Filling device according to claim 8 or 9, characterized in that the spray device (12) has a valve device (20) which is configured to control or regulate the amount of composite material (15) sprayed onto the ballast material (3).

11. Lithium-ion traction battery for a mobile working machine, in particular a forklift truck, using a battery trough (2) manufactured according to one of claims 1 to 7, wherein at least one lithium-ion battery module is installed in the battery trough (2) filled with the ballast material (3).

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