Battery Pack

Abstract

The disclosure describes a battery pack including at least one battery cell, an outer housing that has at least one first housing element, and a cell holder configured to receive the at least one battery cell. In this case the first housing element is constituted by a two-component part that includes at least one first hard component element, one second hard component element and at least one soft component element, the first hard component element and the second hard component element fixedly connected to each other via the at least one soft component element.

Claims

1. A battery pack comprising: at least one battery cell; an outer housing that has at least one first housing element; and a cell holder configured to receive the at least one battery cell, wherein the at least one first housing element is constituted by a two-component part that comprises at least one first hard component element, a second hard component element, and at least one soft component element, the at least one first hard component element and the second hard component element fixedly connected to each other via the at least one soft component element.

2. The battery pack according to claim 1, wherein the outer housing has at least one second housing element that is detachably connected to the at least one first housing element such that the at least one battery cell is held under preload in the outer housing by the at least one soft component element.

3. The battery pack according to claim 1, wherein the at least one first housing element is realized in the form of a shell and at least partially receives the at least one battery cell.

4. The battery pack according to claim 2, wherein the at least one second hard component element is realized as a housing frame element and comprises at least one fastening element configured to detachably fasten the at least one first housing element to the at least one second housing element.

5. The battery pack according to claim 4, wherein the housing frame element has four edges.

6. The battery pack according to claim 1, wherein the at least one first hard component element is realized as a cell carrier element that bears under preload against the at least one battery cell.

7. The battery pack according to claim 6, wherein the cell carrier element has at least one receiver for the at least one battery cell.

8. The battery pack according to claim 6, wherein the cell carrier element is arranged substantially parallel to a longitudinal extent of the at least one battery cell.

9. The battery pack according to claim 1, wherein the at least one soft component element is realized circumferentially around the at least one first hard component element.

10. The battery pack according to claim 1, wherein the second hard component element is realized circumferentially around the at least one soft component element.

11. The battery pack according to claim 1, wherein the at least one soft component element has at least one arc-shaped receiver for the at least one battery cell.

12. The battery pack according to claim 1, wherein the at least one soft component element has at least one edge protection element.

13. The battery pack according to claim 1, wherein the second hard component element has at least one delimiting element configured to delimit movement of the at least one first hard component element relative to the second hard component element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The disclosure is described in greater detail in the following on the basis of the drawings listed below. There are shown

[0026] FIG. 1 a schematic view of a hand-held power tool with a battery pack,

[0027] FIG. 2 an exploded representation of a battery pack,

[0028] FIG. 3 a perspective view of a battery pack according to the disclosure, in longitudinal section,

[0029] FIG. 4 a top view of the first housing element of the battery pack according to FIG. 3,

[0030] FIG. 5 an exploded view of the first housing element according to FIG. 4,

[0031] FIG. 6 a partially exploded view of an alternative first housing element,

[0032] FIG. 7 a longitudinal section, in an exploded view, of an alternative embodiment of the battery pack,

[0033] FIG. 8 a longitudinal section of an alternative embodiment of the battery pack, in a schematic representation.

DETAILED DESCRIPTION

[0034] FIG. 1 shows an electrical appliance realized as a hand-held power tool 300. According to the embodiment represented, the hand-held power tool 300 can be mechanically and electrically connected to a battery pack 100 for off-mains electric power supply. In FIG. 1, the hand-held power tool 300 is realized, by way of example, as a cordless drill/screwdriver. It is to be noted, however, that the present disclosure is not limited to cordless drill/screwdrivers, but rather can be applied to various hand-held power tools 300 that are operated with a battery pack 100. The hand-held power tool 300 has a main body 305, to which a tool receiver 320 is fastened, and has a handle 315, on which a battery pack 100 according to the disclosure is arranged in a locked manner. In the embodiment represented, the battery pack 100 is realized as a sliding battery pack.

[0035] The battery pack 300 has a mechanical interface unit 105 (FIG. 2) for interchangeably attaching the battery pack 100 to the hand-held power tool 300. The interface unit 105 comprises guide elements 110, in the form of guide rails, that act in combination with corresponding receiving elements of the hand-held power tool 300. In the attaching of the battery pack 100, the receiving elements (not represented) of the hand-held power tool 300 are brought into engagement with the guide elements 110 of the battery pack 100, with the battery pack 100 being inserted in a sliding direction y along the receiving elements. The interface unit 105 additionally comprises a locking mechanism, in which a locking element 130 of the battery pack 100 engages in a locking recess (not represented) on the hand-held power tool. An actuating element 120 is provided for releasing the locking element 130. In the position shown in FIG. 1, the battery pack 100 is fastened to the handle 315 of the hand-held power tool 300 and locked by the locking element 130. The battery pack 100 can be detached from the handle 315 of the hand-held power tool 300 by actuation of the actuating element 120. After the battery pack 100 has been unlocked it can be separated from the hand-held power tool 300. For the purpose of electrically contacting the battery pack 100 to the hand-held power tool 300, an electrical interface unit 155 is provided with electrical contact elements 150 that act in combination with corresponding contact means (not represented) on the hand-held power tool 300.

[0036] As represented in FIG. 2, which is an exploded representation of an embodiment of the battery pack 100 according to the disclosure, the battery pack 100 has an outer housing 200 composed of a first housing element 210 and of a second housing element 220. Here, the two housing elements 210 and 220 are detachably connected to each other by four screws 215. To receive the screws 215, the first housing element 210 has four screw eyes 217, and the second housing element 220 has four screw bosses 227 (see FIG. 7).

[0037] The outer housing 200 receives a cell holder 500 that has a plurality of battery cells 400, represented here with five battery cells 400. In the embodiment represented, the battery cells 400 have a cylindrical shape. The cell holder 500 serves to mechanically fix in place the battery cells 400, which are arranged spaced apart from each other on the cell holder 500. For this purpose, the cell holder 500 has a corresponding receiver 520 for each battery cell 400. The receivers 520 are constituted by ribs 510 that are formed onto the cell holder 500 in such a manner that two adjacent battery cells 400 are separated and mutual electrical insulation of the individual battery cells 400 can be provided. The cell holder 500 has elastic tabs 540 as an additional means of fixing the battery cells 400 in place on the cell holder 500. Here, the cell holder 500 is formed from a plastic injection-molded part.

[0038] Moreover, in the embodiment represented here, the cell holder 500 has a set of battery-pack electronics 700, which is fastened to the cell holder 500. The set of battery-pack electronics 700 comprises electrical and electronic components for controlling the battery pack 100 by open-loop ad/or closed-loop control. The electrical and electronic components are mounted on a printed circuit board 710, or are otherwise connected to the printed circuit board 710 in an electrically conductive manner, for example via an electric conductor. The connection between the printed circuit board 710 of the set of battery-pack electronics 700 and the cell holder 500 is provided by fastening elements 530, realized here as latching hooks. Fastened on the printed circuit board 710, inter alia, are the contact elements 150 for effecting an electrical connection between the battery pack 100 and the hand-held power tool 300. Also, by means of the set of battery-pack electronics 700, the state of charge can be monitored, on the basis of the voltage of the individual battery cells 400, and controlled by means of a corresponding closed-loop control. Moreover, individual cells can be monitored, individual battery cells 400 being directly connected to the set of battery-pack electronics 700 by means of contact tongues 730, for example via a soldered connection. Further components, such as temperature sensor, fuse cut-out, may be provided.

[0039] Cell connectors 750 are provided for connecting the battery cells 400 to the set of battery-pack electronics 700, and interconnecting the battery cells 400, in an electrically conductive manner. In the embodiment represented, according to FIG. 2, the terminals of the individual battery cells 400 are interconnected via cell connectors 750 and, because of the series connection represented, in each case two battery cells 400 are interconnected via a cell connector 750 and one battery cell 400 is directly connected to the contact element 150 of the set of battery-pack electronics 700 via a cell connector 750. The cell connectors 750 additionally have wing-type holding elements 760 for fixing the cell connectors 750 in place on the cell holder 500. There are pin-type holding elements 560 formed onto the cell holder 500 for this purpose.

[0040] FIGS. 3 to 7 show further designs of the battery pack 100 according to the disclosure. The first housing element 210 is constituted by a two-component part. The first housing element 210 in this case constitutes an integrated part composed of a plurality of elements. It has a first hard component element 610, e.g. of polyamide, a second hard component element 620, e.g. of polyamide, and a soft component element 630, e.g. of a thermoplastic polymer, the first hard component element 610 and the second hard component element 620 being fixedly connected to each other via the soft component element 630. The first housing element 210 is produced by bi-injection molding. It is realized in the form of a shell. In this embodiment of the battery pack 300 according to the disclosure, the first housing element 210 and the second housing element 220, which are screwed together by means of the screws 215, are connected to each other in such a manner that the battery cells 400 are held under preload in the outer housing 200 by means of the soft component element 630.

[0041] The first hard component element 610 is realized as a cell carrier element 615 that, in the assembled state, bears under preload against the battery cells 400. In the assembled state, the cell carrier element 615 is firmly pressed against the battery cells 400, thereby causing the battery cells 400 to be fixed in place in the outer housing 200. The cell carrier element 615 is formed as a flat, or plate-like, hard component element 610. An inner surface 613 of the cell carrier element 615 bears against the battery cells 400. An outer surface 617 of the cell carrier element 615 constitutes an outer surface of the battery pack 100. The outer surface 617 may serve, for example, as a standing surface for the battery pack 100. The cell carrier element 615 has receivers 619 for the battery cells 400. In the embodiment represented, the receivers 619 have an arc-shaped cross-section, corresponding to the cylindrical battery cells 400, which allows the cell carrier element 615 to bear with surface contact against the envelope of the cylindrical battery cells 400.

[0042] The second hard component element 620 of the first housing element 210 is realized as a housing frame element 625. It is realized in the form of a frame and has four side elements 623.

[0043] The soft component element 630 is realized circumferentially around the first hard component element 610. Moreover, the second hard component element 620 is realized circumferentially around the soft component element 630. In this way, the first hard component element 610 is arranged within the second hard component element 620. In other words, the soft component element 630 is arranged between the first hard component element 610 and the second hard component element 620. In the embodiment represented, the soft component element 630 has a plurality of arc-shaped receivers 639 for the cylinder-shaped battery cells 400.

[0044] In the embodiment represented, according to FIG. 6, the soft component element 630 has a plurality of edge protection elements 635. For easier identification, the soft component element 630 is represented with shading in FIG. 6 (as also in FIG. 5). The edge protection elements 635 are integrally injection-molded onto the soft component element 630, being injection-molded onto the second hard component element 620 in such a manner that the soft component element 630 is injection-molded over, or around, the edges 627 and corners 629 of the second hard component element 620 in order to protect them.

[0045] In the schematic view according to FIG. 7, the second hard component element 620 has a delimiting element 621 that is designed to delimit the movement of the first hard component element 610 relative to the second hard component element 620. The delimiting element 621 is, for example, integrally formed onto the second hard component element 620. It constitutes a projection on the second hard component element 620, in such a manner that it engages underneath the first hard component element 610. FIG. 7 shows a basic state. In this basic state, the soft component element 630 is in a substantially non-stressed state. There is no preload acting upon the first hard component element 610. In this basic state, the first hard component element 610 is spaced apart from the delimiting element 621. The delimiting element 621 is spaced apart relative to the first hard component element 610 so as to allow relative movement of the first hard component element relative to the second hard component element to a certain predefined extent. However, if the first hard component element 610 were to deflect very considerably, i.e. excessively, relative to the second hard component element 620, the deflection would be delimited (downwards in FIG. 7) by the delimiting element 621.

[0046] An alternative embodiment of a battery pack 100 having prismatic battery cells 400′ is shown in schematic and highly simplified form in FIG. 8. The first housing element 210 is constituted by a two-component part. It has a first hard component element 610, e.g. of polyamide, a second hard component element 620, e.g. of polyamide, and a soft component element 630, e.g. of a thermoplastic polymer, the first hard component element 610 and the second hard component element 620 being fixedly connected to each other via the soft component element 630. The first housing element 210 is produced by bi-injection molding. The first housing element 210 and the second housing element 220 are connected to each other in such a manner that the battery cells 400′ are held under preload in the outer housing 200 by means of the soft component element 630. The first hard component element 610 is realized as a cell carrier element 615 that, in the assembled state, bears under preload against the battery cells 400′. In the assembled state, the cell carrier element 615 is firmly pressed against the battery cells 400′, thereby causing the battery cells 400′ to be fixed in place in the outer housing 200. The cell carrier element 615 is formed as a flat, or plate-like, hard component element 610. An inner surface 613 of the cell carrier element 615 bears against what in FIG. 8 is the lowermost battery cell 400′ of the battery cell stack. The cell carrier element 615 has receivers 619 for the battery cells 400′. In the embodiment represented, the receivers 619 are of a shape that is complementary to the prismatic shape of the battery cells 400′ and that allows the cell carrier element 615 to bear with surface contact against what in FIG. 8 is the lowermost prismatic battery cell 400′.