CN111148605A

CN111148605A - Accumulator battery

Info

Publication number: CN111148605A
Application number: CN201880063678.0A
Authority: CN
Inventors: M·雷伊曼; W·察恩; F·克内尔
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-09-29
Filing date: 2018-08-22
Publication date: 2020-05-12
Anticipated expiration: 2038-08-22
Also published as: CN111148605B; DE102017217503A1; WO2019063210A1

Abstract

The invention relates to a battery pack, in particular a battery pack for a hand-held power tool, comprising: a housing in which at least one battery cell is arranged; and the storage battery pack can be mechanically connected with an external electrical appliance through the mechanical interface. It is proposed that the mechanical interface has an improved strength.

Description

Accumulator battery

Technical Field

Background

A mechanical interface for connecting a battery pack to an electrical consumer is known from DE 102015207730 a 1. The mechanical interface is typically made of plastic, such as fiber reinforced polyamide or polycarbonate. As batteries are used in increasingly higher power appliances with higher energy requirements, the weight of the batteries also increases. Due to the increased weight of the battery pack, new requirements for the mechanical interfaces of the battery pack and the electrical consumer arise.

Disclosure of Invention

The invention relates to a battery pack, in particular a battery pack for a hand-held power tool, comprising: a housing in which at least one battery cell is arranged; and the storage battery pack can be mechanically connected with an external electrical appliance through the mechanical interface. It is proposed that the mechanical interface has an improved strength. In particular, it is proposed that the mechanical interface alternatively or additionally have an increased wear resistance. The service life of the battery pack can advantageously be increased thereby.

The battery pack is in particular part of a system consisting of a battery pack and an electrical consumer, wherein the electrical consumer is supplied with energy during operation by the battery pack. In order to establish the mechanical connection between the battery pack and the electrical appliance, the battery pack and the electrical appliance are respectively provided with mechanical interfaces, and the mechanical interfaces correspond to each other. Furthermore, it is also conceivable for the system to comprise an adapter which comprises at least two mechanical interfaces, by means of which the adapter can be mechanically connected to the battery pack and the consumer.

The electric connection between the storage battery pack and the electric appliance is carried out through an electric interface of the storage battery pack and an electric interface of the electric appliance, and the two electric interfaces correspond to each other. In particular, the at least one battery cell of the battery pack can be electrically connected to a drive unit of the consumer via an electrical interface of the battery pack and the consumer. The battery cell can be configured as a galvanic cell having a configuration in which one cell electrode is on one end and the other cell electrode is on the opposite end. In particular, the battery cell has a positive cell electrode on one end and a negative cell electrode on the opposite end. Preferably, the battery cell is designed as a nickel-cadmium battery cell or a nickel-metal hydride battery cell, particularly preferably as a lithium-based battery cell. The battery voltage of a battery pack is generally a multiple of the voltage of the individual battery cells and is obtained by switching the battery cells on (in parallel or in series). Exemplary battery voltages of 3.6 volts, 7.2 volts, 10.8 volts, 14.4 volts, 18 volts, 36 volts, etc., are thus obtained in the case of a typical battery cell having a voltage of 3.6 volts. Preferably, the battery cell is designed as an at least substantially cylindrical round cell, wherein the cell electrodes are arranged on the ends of the cylindrical shape. The electrical interface comprises in particular at least two electrical contact elements which are designed to transfer energy. Alternatively or additionally, the electrical interface can have a charging coil element for inductive charging. In addition, the electrical interface can have further contact elements which are designed to transmit additional information, which is preferably determined by the electronic component, to the electrical consumer. The charge state of the battery pack, the temperature in the battery pack, the code of the battery pack, or the remaining charge can be mentioned, for example. It is conceivable for the electronic components to regulate or control the charging and/or discharging process of the battery pack. The electronic component can have, for example, at least one circuit board, a computation unit, a transistor, a capacitor and/or a memory. The electronic component can also have one or more sensor elements, for example for determining the temperature in the battery pack. Alternatively or additionally, the electronic component can have a coding element, for example a coding resistor.

The electrical consumer can be designed in particular as a portable appliance. Preferably, the consumer appliance is designed as a garden appliance, such as a lawn mower or hedge trimmer, as a hand-held power tool, such as an angle grinder, a screwdriver, an electric drill, a drill hammer, or the like, or as a measuring tool, such as a laser distance measuring device. Alternatively, it is also conceivable that the electrical consumer can be designed as a radio, a lamp or a vacuum cleaner. The battery pack interface is provided in particular for a system of a battery pack and a consumer, in which the weight share of the battery pack is at least 1/8, preferably at least 1/4, preferably at least 1/3, based on the total weight. In the case of such weight ratios, the high weight of the battery pack and the mass inertia of the battery pack can lead to extremely high loads of the mechanical connection in the event of a system drop, which can lead to irreversible damage of the mechanical interface. The mechanical interfaces of the battery pack and of the consumer are in particular designed to form a non-positive and/or positive connection with one another. The connection is preferably designed to be releasable, wherein, in connection with the present application, a releasable connection is to be understood as a connection that can be released without tools and without damage. Preferably, at least one of the mechanical interfaces comprises a fastening element, by means of which the battery pack can be fastened to the electrical consumer. Preferably, the fastening can be released by an actuating element, wherein the actuating element can be arranged on the battery pack and/or the consumer. The actuating element can be configured, for example, as a push button, lever or push button.

A mechanical interface with increased strength and/or wear resistance is understood in the context of the present application to be, in particular, a mechanical interface of a battery pack or of an electrical consumer, which is reinforced by means of suitable structural measures or by the selection of materials. Preferably, the mechanical interface has at least in part a higher tensile strength and/or yield strength than the housing of the battery pack or the housing of the consumer. Preferably, the average tensile strength and/or the average yield strength of the mechanical interface is greater than the average tensile strength and/or the yield strength of the housing of the battery pack or the electrical consumer, in particular in the region of the respective mechanical interface. Yield strength is understood in this context to be the boundary from which the tensile-loaded component passes through the transition from the elastic region to the plastic region.

It is also proposed that the mechanical interface has a support surface and that the ratio between the support surface of the mechanical interface and the weight of the battery pack is less than 5 cm/kg, in particular less than 1 cm/kg, preferably less than 0.5 cm/kg. Alternatively, it is also conceivable for the ratio between the support surface of the mechanical interface and the weight of the battery pack to be in the range between 0.2 cm/kg and 0.8 cm/kg, preferably between 0.3 cm/kg and 0.5 cm/kg. In this context, a support surface is to be understood in particular as meaning the entire support surface. Advantageously, the mechanical interface with increased strength is thereby constructed only in systems requiring such a mechanical interface. The support surface of the mechanical interface is understood in this context to mean, in particular, the surface of the battery pack or of the electrical consumer, which is acted upon by the electrical consumer or the battery pack with force. In this case, the support surface is oriented substantially perpendicular to the active weight force during normal operation of the consumer.

It is also proposed that the housing is substantially composed of a housing material, and that at least one reinforcing element is arranged in at least one connecting region of the mechanical interface, which reinforcing element is composed of a material having a higher strength and/or wear resistance than the housing material. Advantageously, the strength of the mechanical interface can thereby be effectively increased. Material is understood in this context to mean, in particular, a mass from which the component is composed. The housing of the battery pack is in particular at least partially made of plastic. Preferably, the housing is constructed of polycarbonate or polyethylene, preferably polyethylene with high density (PE-HD). The housing is at least partially, in particular completely, designed as an outer housing. The shell material is to be understood in this context in particular as meaning a material from which at least 50%, preferably at least 75%, preferably at least 90%, of the shell consists. In the connection region, the mechanical interface of the battery pack rests at least partially against the mechanical interface of the electrical consumer in the connected state. The support surface is arranged in particular completely in the connecting region. Preferably, the material of the connecting region and/or of the reinforcing element has a higher tensile strength and/or yield strength than the material of the housing. In particular, the average tensile strength and/or yield strength of the housing is increased by the reinforcing element.

It is also proposed that the connection region of the mechanical interface comprises a connection element which is designed to connect the battery pack to the consumer in a force-locking and/or form-locking manner. The connecting element is in particular connected to the reinforcing element in such a way that the strength and/or the wear resistance of the connecting element is increased.

Furthermore, it is proposed that the connecting element and/or the reinforcing element are designed in such a way that the battery pack can be guided through the connecting element and/or the reinforcing element in order to establish a force-locking and/or form-locking connection. The connecting element can be configured, for example, as a guide rail, in particular a linear guide rail, a guide groove, a guide rib or the like.

It is also proposed that the reinforcing element be arranged partially, in particular completely, on the outer surface of the connecting element. The strength and the wear resistance of the connecting element can advantageously be increased by these measures. The outer surface of the connecting element can be designed in particular as a guide surface along which the battery pack can be guided for establishing a force-locking and/or form-locking connection. In addition, the outer surface is in particular designed as a support surface which is acted upon by the weight of the consumer or the battery pack in the connected state.

It is also proposed that the reinforcing element is partially or completely surrounded by the connecting element. Advantageously, the strength of the mechanical interface, in particular of the connecting element, can thereby be increased. In particular, the reinforcing element is arranged at a distance from the outer surface of the connecting element, whereby the reinforcing element is advantageously protected from wear and/or corrosion by the connecting element.

Furthermore, it is proposed that each connecting element is connected to at least one reinforcing element, in particular a single reinforcing element. It is also proposed that a plurality of connecting elements are connected to a single reinforcing element. The strength can advantageously be increased particularly effectively thereby.

It is also proposed that the reinforcing element can be connected to the connecting element in a force-fitting and/or form-fitting manner. The connection can be designed to be releasable, in particular tool-free. It is exemplary conceivable for the reinforcing element to be connected to the connecting element by means of a screw connection, a clamping connection, an adhesive connection or the like. Alternatively or additionally, it is also conceivable for the reinforcing element to be connected to the connecting element by a connection which cannot be released or can only be released under certain conditions, for example by injection molding or heat staking.

Furthermore, it is proposed that the reinforcing element be designed as an insert. Advantageously, the reinforcement of the mechanical interface can thereby be realized in a cost-effective manner. It is also proposed that the connecting element is produced by injection molding of the reinforcing element.

It is also proposed that the reinforcing element is constructed from a metal or a metal alloy. Alternatively or additionally, the reinforcing element can be composed of a plastic different from the plastic of the housing or of a ceramic.

Furthermore, it is proposed that the housing be designed in multiple parts, wherein the housing has at least one interface housing, which comprises a mechanical interface. The assembly of the battery pack and/or the electrical consumer can advantageously be simplified by the multipart housing.

It is also proposed that the interface housing is constructed substantially from a metal or a metal alloy. A mechanical interface with particularly high strength and/or wear resistance can advantageously be realized thereby. The interface housing is preferably constructed of a non-ferrous metal. Preferably, the interface housing is constructed from a non-ferrous metal alloy based on aluminum, zinc or magnesium. The non-ferrous metal alloy herein has an iron content of not more than 50%.

It is also proposed that the interface housing has at least one connecting element, wherein the connecting element is made of a metal or a metal alloy. A mechanical interface with a high strength can thus advantageously be realized in a structurally advantageous manner.

Furthermore, it is proposed that the interface housing partially encloses at least one electrical contact element, which is designed to electrically connect the at least one battery cell to the consumer, in the electrical contact region. The electrical contact element is assigned in particular to the aforementioned electrical interface. Advantageously, the at least one electrical contact element is protected by the interface housing.

It is also proposed that the interface housing has at least one insulating element, which is arranged in the electrical contact region. Short circuits can advantageously be prevented by the insulating element. The insulating element is in particular arranged between two electrical contact elements or between an electrical contact element and an interface housing, in particular a conductive region and/or a metal region of an interface housing. The insulating element is in particular designed as an electrical insulator.

It is also proposed that the insulating element be connected to the interface housing in a force-fitting, form-fitting and/or material-fitting manner. The insulating element can be configured as an injection-molded part, as an insulating film or as a coating.

Furthermore, it is proposed that the battery pack has at least one heat conducting element which is designed for the thermal connection between the interface housing and a heat source arranged in the housing of the battery pack. A heat source is to be understood in this context to mean, in particular, an energized component within the battery pack, in particular in the region of the electronic components of the battery pack, or a component heated by the energized component. The heat source can be, for example, a circuit board of an electronic component, an electronic component arranged on the electronic component, a solder or weld joint, an electrical lead, a fuse, etc. Preferably, the heat conducting element has a higher heat conducting capacity than air. Preferably, the heat conducting element has a higher heat conducting capacity than the average heat conducting capacity of the housing. The heat conducting element can be formed by a heat conducting medium, for example a heat conducting paste or a heat conducting film.

It is also proposed that the heat-conducting element be connected to the interface housing and/or the heat source in a force-fitting, form-fitting and/or material-fitting manner. The heat-conducting element rests in particular on the interface housing and the heat source.

The invention also relates to a method for producing a battery pack having the aforementioned mechanical interface, in which method the mechanical interface is produced, in particular, by means of a multicomponent injection molding method. In particular, at least one plastic component has a higher tensile strength, wherein the component is used for producing the reinforcing element. In particular, the interface housing is manufactured by a multi-component injection molding process.

Alternatively, the mechanical interface can be produced by means of a die casting method or a hybrid injection molding method. In particular, the interface housing, which is substantially composed of metal or a metal alloy, is produced by means of a die-casting method, whereas the interface housing, which is substantially composed of plastic and has a reinforcing element in the form of a metal insert, is produced by means of a hybrid injection molding method. It is also proposed that the connecting element is produced by injection molding of the reinforcing element.

It is furthermore proposed that the reinforcing element has at least one hole or at least one recess. Preferably, the reinforcing element has a plurality of holes or recesses which, in the case of an injection-molded reinforcing element, lead to a better adhesion or connection of the plastic to the reinforcing element.

The invention further relates to an electrical consumer, in particular a hand-held power tool, having the aforementioned mechanical interface. The invention also relates to a system comprising a battery pack and an electrical consumer, which system has at least one mechanical interface as described above, preferably the battery pack and the electrical consumer each have one mechanical interface as described above.

Drawings

Further advantages are obtained from the following description of the figures. The figures, description and claims contain a number of combinations of features. Those skilled in the art can suitably view these features individually and generalize them into meaningful other combinations. Substantially corresponding reference numerals for features of different embodiments of the invention are provided with the same numerals and letters that designate the embodiments.

In the latter exemplary embodiment, the mechanical interface according to the invention is assigned to the battery pack. Since the mechanical interface of the load substantially corresponds to the mechanical interface of the battery pack, the person skilled in the art will readily recognize that the illustrated embodiment of the mechanical interface of the battery pack is applied to the corresponding mechanical interface of the load.

The figures show:

FIG. 1 is a side view of a system including an electrical consumer and a battery pack;

fig. 2 is a perspective view of the battery pack;

fig. 3 is a perspective view of the battery pack according to fig. 2 without the interface housing;

FIG. 4a is an exploded view of a mechanical interface according to the present invention;

FIG. 4b is a cross-section of the mechanical interface according to FIG. 4 a;

FIG. 5 is a cross-section through plane A shown in FIG. 1;

FIG. 6 is an exploded view of an alternative embodiment of a mechanical interface according to the present invention;

FIG. 7a is an exploded view of an alternative embodiment of a mechanical interface;

FIG. 7b is a cross-section of the mechanical interface according to FIG. 7 a;

FIG. 8 is a top view of a battery pack with a further alternative embodiment of a mechanical interface;

fig. 9a is a cross section (through plane B) of the battery according to fig. 8;

fig. 9b is a longitudinal section through the battery pack of fig. 9a (through plane C);

fig. 10 is a longitudinal section of a battery pack with a further alternative embodiment of a mechanical interface.

Detailed Description

Fig. 1 shows a side view of a system 10, which comprises an electrical consumer 14 in the form of a hand-held power tool 12 and a battery pack 18 in the form of a hand-held power tool battery pack 16. The hand-held power tool 12 and the battery pack 18 each have a mechanical interface 20, 22, and the two components of the system 10 are connected to one another via the mechanical interfaces 20, 22. The hand-held power tool 12 is configured as a drill hammer 24. The hand-held power tool 12 has a housing 26, on the rear end of which a handle 28 is arranged, which has an operating switch 30 for switching the hand-held power tool 12 on and off. A tool receiver 31 is arranged on the front end of the housing 26 of the hand-held power tool 12, which tool receiver is provided for receiving an application tool 32. A drive unit 38 having an electric motor 34 and a transmission 36 is arranged between the handle 28 and the tool receiving portion 31. The transmission 36 includes an impact mechanism unit 40 and is disposed above the electric motor 34. Disposed below the electric motor 34 is an electronic component 42, by means of which the hand-held power tool 12 can be adjusted or controlled. The battery pack 18 is disposed below the handle 28 and adjacent to the electronic components 42. The battery pack 18 and the consumer 14 have an electrical interface 44, 46, respectively, which correspond to each other and by means of which the battery pack 18 can be electrically connected to the consumer 14, in particular to the electronic components 42 of the consumer 14. In the interconnected state, the battery pack 18 provides the electrical consumer 14 with a power supply. The battery pack 18 has a weight corresponding to about 1/4 of the weight of the system 10. By means of the weight and the arrangement of the battery pack 18, increased loads in the region of the mechanical interfaces 20, 22 are obtained during operation of the system 10. In order to extend the service life of the system 10, in particular of the mechanical interfaces 20, 22, the mechanical interfaces 20, 22 are constructed such that they have an increased strength.

In fig. 2, the battery pack 18 and the mechanical interface 22 are shown in a perspective view. The battery pack 18 is releasably mechanically connected to the consumer 14 via a mechanical interface 22. The battery pack 18 has a housing 48, which is designed in multiple parts, as an example. The housing 48 is made of a housing material containing plastic. Preferably, the housing 48 is constructed of polycarbonate or polyethylene having a high density. The housing 48 has a base 50 on its underside, an interface housing 52 on its upper side and two opposing side walls 54 on its sides. The

housing parts

50, 52, 54 are connected to one another by fastening elements 56, which are configured as screws by way of example. The

housing parts

50, 52, 54 are each at least partially designed as an outer housing part. On the front side of the battery pack 18, a charge state indicator 58 is arranged, by means of which the charge state of the battery pack 18 can be indicated. The charge status indicator 58 is integrated in the housing 48, in particular in the base body 50. The housing 48, in particular the interface housing 52, comprises the mechanical interface 22 with the fastening element 60 and the electrical interface 46. The battery pack 18 is illustratively configured as a push-on battery pack. When the battery pack 18 is installed, the connecting elements 62, which are designed as guide grooves in an exemplary manner, of the mechanical interface 22 of the battery pack 18 are brought into engagement with corresponding connecting elements 64, which are designed as guide rails in an exemplary manner, of the mechanical interface 20 of the consumer 14 (see fig. 4). The battery pack 18 is inserted into the hand-held power tool 12 by means of a relative movement in an insertion direction 66 and is guided there by a connecting element 62 of the battery pack 18 and a connecting element 64 of the electrical consumer. The battery pack 18 is connected to the consumer 14 in a non-positive and positive-locking manner in a releasable manner by the connecting

elements

62, 64 of the two mechanical interfaces 20, 22. The relative movement for connecting the battery pack 18 has one degree of freedom.

In order to lock the battery pack 18 to the consumer 14, the mechanical interface 22 has a fastening element 60. The fastening element 60 is designed as a spring-loaded latching element which is mounted pivotably in the housing 48 of the battery pack 18. This locking is effected by the battery pack 18 being pushed in the push-in direction 66, the fastening element 60 snapping into the latching region at the end of the relative movement. To release the locking, the mechanical interface 22 has an actuating element 68 in the form of a push button, which is coupled in terms of movement to the fastening element 60. By actuating the actuating element 68, the fastening element 60 is moved into the housing 48 of the battery pack 18, and the locking between the battery pack 18 and the electrical consumer 14 is released, so that the battery pack 18 is released by a movement opposite to the relative movement in the insertion direction 66.

The battery pack 18 is shown in fig. 3 without the interface housing 52 and side walls 54. The base 50 of the housing 48 has a single body retainer region. At least one battery cell 70 is received in the cell holder region, the battery pack 18 in this embodiment having ten battery cells 70 connected in parallel and/or in series. The battery cells 70 are arranged in two layers, each layer having five battery cells 70. The battery cell 70 is of cylindrical design and has a cell electrode 72 on its end face. The battery cells 70 are connected to one another by cell connectors 74. Cell connectors 74 are configured to electrically connect battery cells 70 in parallel and/or in series. In the embodiment shown, two or four battery cells 70 are connected to one another via cell connectors 74. It can also be seen that the battery cells 70 are received at a distance from one another for mechanical fastening in the cell holder region of the base body 50. The cell holder region serves, in addition to fixing the battery cells 70 in the housing 48, also for cooling the battery cells 70 and is made of a thermally conductive material, for example aluminum or a thermally well-conducting plastic. Furthermore, the cell holder region has a sleeve-like insulating wall, so that the battery cells 70 are separated and independent and an electrical insulation of the battery cells 70 from one another is ensured.

Above the cell holder region, in particular in the region between the base body 50 and the interface housing 52, electronic components 78 are arranged. The electronic component 78 includes a circuit board 80. The electronic components 78 are connected to the charge status indicator 58. An electrical contact element 82 and a further contact element 84 are arranged on the circuit board 80, the electrical contact element 82 being provided for charging and discharging the battery pack 18, and the further contact element 84 being designed to transmit status information of the battery pack 18, for example the state of charge or the temperature, to the electrical consumer 14. An electrical contact element 82 and a further contact element 84 are associated with the electrical interface 46. The

electrical contact elements

82, 84 are arranged in a recess 83 (see fig. 2) in the housing 48, in particular in the interface housing 52, in the assembled state of the battery pack 18. Electrical contact elements 82 are connected to electronic components 78 and battery cell 70. The electrical connection of the electrical contact elements 82 to the battery cells 70 takes place via contact points 86, embodied as soldering points, at which the battery cells 70 are soldered via the cell connections 74 to electrical conductors 88 embodied as wires. Alternatively, it is also conceivable for the individual connections 74 to be welded to the electrical conductors 88. Solder joints 86 are disposed between the electronic components 78 and the battery cells 70.

An exploded view of the interface housing 52 is shown in fig. 4 a. The interface housing 52 is configured as part of the outer housing of the battery pack 18. The interface housing 52 includes the mechanical interface 22 of the battery pack, which is configured to have improved strength and wear resistance. For this purpose, the interface housing 52 is connected in a form-fitting manner to two reinforcing elements 90, which are arranged in particular in a connecting region 92 of the mechanical interface 22. The interface housing 52 is of the same material as the housing material of the housing 48. The interface housing 52 is constructed, in particular, from plastic. The reinforcing element 90 is constructed from sheet metal. The reinforcing element 90 is in particular designed as a stamped and bent part. The connecting region 92 is formed by a region in which the connecting elements 62 of the battery pack 18 form a force-locking and form-locking connection with the corresponding connecting elements 64 of the consumer 14. The connecting element 62 of the battery pack 18, which is designed as a guide groove, extends substantially parallel to the insertion direction 66. For the purpose of establishing a force-fitting connection, it is conceivable for the connecting element to have, for example, a conical subsection. The interface housing 52 has two connecting elements 62, which are each connected to a single reinforcing element 90. The connection of the interface housing 52 to the reinforcing element 90 is designed to be non-releasable and is produced in particular during the production of the interface housing 52. Preferably, the interface housing 52 is produced by a hybrid injection molding method, in which the reinforcing element 90, which is designed as a sheet metal insert, is inserted into an injection mold for the interface housing 52 and is injection molded, in particular in plastic. Alternatively, it is also conceivable for the reinforcing element 90 to be connected to the connecting element 62 by other connecting means, for example by gluing, in a material-locking manner. The reinforcing member 90 has a plurality of cutouts 94 to reinforce the connection between the interface housing 52 and the reinforcing member 90. The length of the reinforcing element 90 preferably corresponds to the length of the connecting element 62, wherein the length of the connecting element 62 is understood in particular to be the length of the region of the connecting element 62 in which the battery pack 18 is guided during connection to the consumer 14. Alternatively, it is also conceivable for the length of the reinforcing element 90 to correspond to at least 30% of the length of the connecting element 62, in particular at least 50% of the length of the connecting element 62, preferably at least 75% of the length of the connecting element 62. It is also conceivable for more than one reinforcing element 90 to be connected to and reinforce one connecting element 62.

Fig. 4b shows a perspective cross section of the interface housing 52 connected to the reinforcing element 90. The reinforcing element 90 is connected to the mechanical interface 22 or the interface housing 52 in such a way that, in cross section, a part of the reinforcing element 90 is completely enclosed by the interface housing 52 and a part is enclosed on one side by the interface housing 52. The cross-sectional profile of the reinforcing member 90 may take on various shapes, such as an L-shape, U-shape, T-shape, double T-shape, or a combination of these shapes. The reinforcing element 90 is in particular arranged such that the reinforcing element 90 is configured as an outer surface 96 of the connecting element 62. Preferably, the reinforcing element 90 is constructed of a corrosion resistant metal or corrosion resistant metal alloy. The reinforcing element 90 is preferably designed as a support surface 98 of the connecting element 62, which in the connected state rests against the corresponding connecting element 64 of the consumer 14 and acts on the weight force, based on the weight of the battery pack 18. The interface housing 52 is connected to a further housing part 54 of the housing 48 of the battery pack 18 by means of fastening elements 56 designed as screws. For this purpose, the interface housing 52 has a fastening element receiver 100 (see fig. 4a), which is configured, for example, as a screw receptacle. In order to further increase the strength of the mechanical interface 22, the reinforcing element 90 likewise has at least one fastening element receptacle 102 (see fig. 4a), which in the connected state is arranged adjacent to the fastening element receptacle 100 of the interface housing 52, so that the fastening element 56 is received by the two

fastening element receptacles

100, 102. Advantageously, the forces acting on the support surface 98 are thus also received by at least one or both of the fastening elements 56.

Fig. 5 shows a cross section of the mechanical interface 20 of the load 14 and the mechanical interface 22 of the battery pack 18 of the system 10 from fig. 1. The electrical load 14 has an electrical interface 44, which comprises a plurality of electrical contacts 104, via which the electrical interface 44 of the electrical load 14 can be electrically connected to the electrical interface 46 of the battery pack 18. The electrical contact 104 is arranged on a contact holder 105, the contact holder 105 being fastened in the handle 28 of the electrical consumer 14, in particular in the foot of the handle 28 of the electrical consumer 14.

In this embodiment, the connecting elements 64 of the consumer 14, which are designed as guide rails, engage in corresponding connecting elements 62 of the battery pack 18, which are designed as guide grooves. In this embodiment, only the mechanical interface 22 of the battery pack 18 is reinforced by the reinforcing element 90. Alternatively or additionally, however, it is also conceivable for the mechanical interface 20 of the consumer 14 to be designed with stiffening elements. The connecting element 64 rests against three outer faces of the connecting element 62 of the battery pack 18, wherein two of the three outer faces of the connecting element 62 are formed by the reinforcing element 90. During normal operation of the hand-held power tool 12, the orientation of the system 10 corresponds substantially to the orientation shown in fig. 1, in which the battery pack 18 is arranged on the lower end of the hand-held power tool 12. In this orientation, as described above, forces based on the weight of the battery pack 18 act on the support surface 98 of the connecting element 62.

In fig. 6, an alternative embodiment of a mechanical interface 22a is shown, which has an alternative reinforcing element 90 a. The mechanical interface 22a comprises a single reinforcing element 90a, which is connected to the interface housing 52a in such a way that all connecting elements 62a of the mechanical interface 22a are reinforced by this single reinforcing element 90 a. The reinforcing element 90a comprises two partial regions 106a, which substantially correspond to the reinforcing element 90 of the preceding exemplary embodiment, wherein the two partial regions 106a are connected to one another by a transverse beam 108 a. The strength of the mechanical interface 22a can advantageously be further increased thereby.

Fig. 7a shows a further alternative embodiment of the mechanical interface 22b with an alternative reinforcing element 90 b. The interface housing 52b is constructed of plastic as previously described and includes two connecting elements 62 b. The connecting elements 62b are connected to a respective reinforcing element 90b as described above, in particular by means of a co-injection molding process. The reinforcing element 90b is designed as a sheet metal insert and extends along the longitudinal extension of the connecting element 62 b. The reinforcing element 90b has a plurality of holes 94, through which the connection of the reinforcing element 90b to the connecting element 62b can be reinforced by the interface housing 52b or the connecting element 62b and the reinforcing element 90b being gripped during the production process. Furthermore, the reinforcing elements 90b each have three fastening element receptacles 102 b.

A cross section of the mechanical interface 22b is shown in fig. 7 b. Unlike the embodiment of the mechanical interface 22 of fig. 4, the reinforcing element 90b does not constitute the outer surface 96b of the connecting element 62 b. As can be seen in the cross section, the reinforcing element 90b is substantially completely enclosed by the interface housing 52b or the connecting element 62b in the connecting region. Preferably, the reinforcing element 90b is surrounded by the interface housing 52b in such a way that the reinforcing element 90b is shielded from moisture by the interface housing 52b, so that external moisture does not contact the reinforcing element 90 b. It is advantageously possible to use a metal or a metal alloy that is not corrosion-resistant for the production of the reinforcing element 90 b.

Fig. 8 shows a further alternative embodiment of a battery pack 18c in a plan view, which has a mechanical interface 22 c. The battery pack 18c is constructed essentially in accordance with the battery pack 18 of fig. 2 and 3, but differs essentially in the mechanical interface 22c, which has a metallic interface housing 52 c. The housing 48c of the battery pack 18c is in this embodiment made up primarily of plastic or a material containing plastic. In this context, it is to be understood in particular that at least 50%, preferably at least 75%, of the outer surface of the housing is formed from plastic or a plastic-containing material. In particular, the base 50c and the side walls 54c are formed from a plastic-containing material. The interface housing 52c is illustratively constructed of aluminum. But alternatively other metals or metal alloys, especially non-metals, are also suitable. The interface housing 52c comprises a connecting element 62c, which is designed as described above for a non-positive and/or positive connection to the consumer 14. The connecting element 62c is formed integrally with the interface housing 52c and is in particular formed as a guide groove. The outer surface 96c of the connecting element 62c is partially designed as a guide surface along which the battery pack 18c is guided when connected to the consumer 14. The outer surface 96c of the connecting element 62c is preferably machined such that wear in the area of the guide surface is reduced. For example, the outer surface 96c may be machined by milling, grinding, polishing, or the like. By means of the metallic mechanical interface 22c, the battery pack has a higher tensile strength and yield strength in the region of the mechanical interface 22c, in particular in the region of the connecting element 62c, than the average tensile strength and yield strength of the housing 48 c.

In fig. 9a cross section through the plane B shown in fig. 8 is shown. Plane B extends through the interface housing 52c and the

electrical contact elements

82c, 84c disposed in the notches 83c of the interface housing 52 c. The region in which the

electrical contact elements

82c, 84c are arranged, in particular the region spanned by the notches 83c, forms an electrical contact region 112c, in which the electrical contact element 82c or the further electrical contact element 84c can be electrically connected to the corresponding electrical interface 44 of the consumer 14. The

electrical contact elements

82c, 84c are in particular each arranged between two side walls 110c of the interface housing 52, which delimit an electrical contact region 112c in terms of space. The

electrical contact elements

82c, 84c are configured as spring contact ends by way of example. To ensure that electrical contact of the

electrical contact elements

82c, 84c with the electrically conductive interface housing 52c is not established, the battery pack 18c has an insulating element 114 c. The insulating element 114c is preferably connected to the interface housing 52c by a force-locking connection and/or a form-locking connection or by a material-locking connection. The insulating element 114c is arranged in particular between the

electrical contact elements

82c, 84c of the electronic component 78c of the battery pack 18c or other electrically energized elements, for example an electronic component 81c (see fig. 9b), in such a way that the interface housing 52c is not subjected to current, as a result of which a short circuit is advantageously prevented in the case of a metallic interface housing 52 c. The insulating element 114c can be formed, for example, as an insulating film 116 c. The insulating element 114c, which is designed as an insulating film 116c, can be connected, for example, in a cohesive manner by adhesive bonding to the side walls 112c surrounding the

electrical contact elements

82c, 84. Disposed below the

electrical contacts

82c, 84c is the circuit board 80c, and disposed above the

electrical contacts

82c, 84c is the interface housing 52 c. In particular, an insulating element 114c, which is designed, for example, as an insulating insert 118c (see fig. 9b), is also arranged on the inner surface of the interface housing 52c above the

electrical contact elements

82c, 84 c. The insulating insert can be designed as an injection-molded part and can be mounted on the inner surface of the interface housing 52c by means of a clamping connection. Alternatively, it is also conceivable for the entire inner surface of the interface housing 52c to be coated with an electrically insulating plastic coating.

Fig. 10 shows a further alternative embodiment of a battery pack 18d, which has a mechanical interface 22 d. Similar to the previous embodiments, the mechanical interface 22d is of metallic design. The battery pack 18d is shown in longitudinal section. On the inner surface of the interface housing 52d, an insulating element 114d is arranged above the electronic component 78d, in particular above the circuit board 80 d. A heat source 120d, which heats up when the battery pack 18d is charged or discharged, is arranged in the battery pack 18d, in particular on the circuit board 80 d. The heat source 120d may be configured as an energized component or may also be configured as a component that heats up as a result of the energized component. For effective cooling, the battery pack 18d has a heat conducting element 122d, which is designed to thermally connect the heat source 120d to the metallic interface housing 52d, as a result of which an effective removal of heat from the inner housing 48d of the battery pack 18d can be advantageously achieved. The heat conductive element 122d is exemplarily configured as a heat conductive film configured to be adhesively bonded on both sides for the sake of simple assembly. The heat-conducting element 122d in particular directly contacts both the heat source 120d and the interface housing 52 d. The dimensions of the heat-conducting element 122d are preferably substantially adapted to the dimensions of the heat source 120d to be cooled. Advantageously, the insulating element 114d has a slot in which the heat conducting element 122d is arranged and through which the heat conducting element 122d can be thermally connected with the interface housing 52 d. The heat conducting element 122d is in particular electrically insulated.

Claims

1. A battery pack, in particular a battery pack for a hand-held power tool, comprising: a housing (48) in which at least one battery cell (70) is arranged; a mechanical interface (22) via which the battery pack (18) can be mechanically connected to an external consumer (14),

it is characterized in that the preparation method is characterized in that,

the mechanical interface (22) has an increased strength.

2. The battery pack according to claim 1, characterized in that the mechanical interface (22) has a bearing surface (98), and in that the ratio of the bearing surface (98) of the mechanical interface (22) to the weight of the battery pack (18) is less than 5 cm/kg.

3. Battery pack according to one of the preceding claims, characterized in that the casing (48) is constructed substantially from a casing material and in that at least one reinforcement element (90) is arranged in at least one connection region (96) of the mechanical interface (22), which reinforcement element is constructed from a material having a higher strength than the casing material.

4. The battery pack according to claim 3, characterized in that the connection region (96) of the mechanical interface (22) comprises a connection element (62) which is designed for a force-locking and/or form-locking connection of the battery pack (18) to the electrical consumer (14).

5. The battery pack according to claim 3 or 4, characterized in that the connecting element (62) and/or the reinforcing element (90) are designed such that the battery pack (18) can be guided by the connecting element (62) and/or the reinforcing element (90) in order to establish a force-locking and/or form-locking connection.

6. The battery pack according to claim 4 or 5, characterized in that the reinforcement element (90) is arranged partially, in particular completely, on an outer surface (96) of the connecting element (62).

7. Battery pack according to one of claims 4 to 6, characterised in that the reinforcement element (90b) is partially or completely surrounded by a connecting element (62 b).

8. Battery pack according to one of claims 4 to 7, characterised in that each connecting element (62) is connected to at least one stiffening element (90), in particular to a single stiffening element (90).

9. Battery pack according to one of claims 4 to 7, characterised in that a plurality of connecting elements (62a) are connected to a single reinforcing element (90 a).

10. The battery according to one of claims 4 to 7, characterized in that the reinforcement element (90) can be connected to the connecting element (62) in a force-fitting and/or form-fitting manner.

11. The battery pack according to one of claims 3 to 10, characterized in that the reinforcing element (90) is configured as an insert.

12. The battery according to claim 11, characterized in that the connecting element (62) is produced by injection molding a reinforcing element (90).

13. The battery according to one of the claims 3 to 12, characterized in that the reinforcing element (90) is constructed from a metal or a metal alloy.

14. The battery pack according to one of claims 3 to 12, characterized in that the reinforcing element (90) is constructed from a plastic different from the plastic of the housing (48) or from a ceramic.

15. Method for producing a battery pack according to one of the preceding claims, characterized in that the mechanical interface (22) is produced by means of a multi-component injection molding method or by means of a hybrid injection molding method.

16. Method according to claim 15, characterized in that the connecting element (62) is manufactured by injection-moulding the reinforcing element (90).

17. Method according to claim 15 or 16, characterized in that the reinforcing element (90) has at least one hole (94) or at least one recess (94).

18. An electrical consumer, in particular a hand-held power tool, for connection to a battery pack, having a mechanical interface (22; 22 a; 22b) according to one of claims 1 to 14.

19. A system of a battery pack (18; 18 a; 18b) and a consumer (14), having a mechanical interface (22; 22 a; 22b) according to any one of the preceding claims.