CROSS REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 from European Patent Application No. 19150490.1, filed Jan. 7, 2019, the entire disclosure of which is herein expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a cell holder structure for holding a plurality of rechargeable battery cells, wherein the cell holder structure comprises a holder base part and a holder cover part which is connectable to the latter, said holder base part and holder cover part together forming an array of cell receiving spaces and cell intermediate spaces lying inbetween. The invention furthermore relates to a rechargeable battery pack comprising such a cell holder structure and comprising rechargeable battery cells held by the latter.

Various embodiments of cell holder structures of this type are known. They serve to hold the rechargeable battery cells which are typically suitably connected electrically in series and/or in parallel in order to supply an electrical device with electrical energy. For this purpose a multiplicity of structurally identical rechargeable battery cells, in particular of circular cylindrical design or another elongated design, are generally arranged and held in the cell receiving spaces of the cell holder structure, and the cell holder structure with the inserted rechargeable battery cells is conventionally used in a rechargeable battery pack, for example arranged in a housing of the rechargeable battery pack. The cell receiving spaces are arranged in an array, i.e. in a two dimensional arrangement which is typically a regular arrangement, e.g. a rectangular grid or triangular grid arrangement. When required, a plurality of such two dimensional arrays of cell receiving spaces and cell intermediate space lying inbetween can be provided lying one above other, i.e. offset with a direction component perpendicular to a plane of the array, within the same cell holder structure or by using one or more further cell holder structures.

The rechargeable battery cell pack equipped with such a cell holder structure and the rechargeable battery cells held in the latter can serve in particular for the electrical energy supply of a hand held electrical device, such as a portable or ground guided garden and/or forest processing device. For example, the rechargeable battery pack can be such as is disclosed in the applicant's earlier EP application No. 18194901.7, the contents of which are hereby incorporated into the description by reference.

A battery pack with a cell holder structure of the type mentioned at the beginning is disclosed in laid open application DE 10 2011 101 022 A1. The cell holder structure there is configured specially for holding circular cylindrical battery cells and, with its cell receiving spaces, is configured for receiving all battery cells, i.e. rechargeable battery cells, having an identical pole direction, that is to say that, for example, the positive pole of all of the rechargeable battery cells faces the holder base part or the holder cover part. For the play free holding of the rechargeable battery cells in the cell receiving spaces, spring tongues which provide an axial spring force are proposed on the holder base part and spring webs which provide a radial spring force are proposed on the holder cover part. For the electrical connection of the rechargeable battery cells in parallel and series group by group, use is made of plate like cell connectors which can be mounted on the holder base part or on the holder cover part and are provided with contact tongues which are bent at a right angle and run along a wall side of a housing which is formed by the holder base part and four wall sides.

It is an object of the invention to provide a cell holder structure of the type mentioned at the beginning which, with relatively little outlay, permits improved holding of the rechargeable battery cells in comparison to the prior art mentioned above. Furthermore, the invention is based on providing a rechargeable battery pack equipped with such a cell holder structure.

The invention achieves this and other objects by providing a cell holder structure and a rechargeable battery pack according to the claimed invention. The cell holder structure is configured to hold a plurality of rechargeable battery cells for a rechargeable battery pack and comprises a holder base part and a holder cover part which is connectable to the latter, said holder base part and holder cover part together forming an array of cell-receiving spaces and cell intermediate spaces lying inbetween.

According to one aspect of the invention, the holder base part, which may also be referred to as holder rear side part or holder front side part or holder lower side part or holder upper side part, has one or more base side cell supporting pillars which extend axially from a base plane of the holder base part into assigned cell intermediate spaces and have a circumferential side securing wall region which is configured for abutting in an axially and radially position securing manner against a circumferential surface of rechargeable battery cells to be accommodated in the cell receiving spaces. Axially means a longitudinal direction of the cell receiving spaces and therefore also of the rechargeable battery cells when the latter are inserted into the cell receiving spaces, i.e. a direction which is non parallel and is preferably perpendicular to the base plane of the holder base part. Radially means a lateral direction or plane perpendicular to the axial direction. The cell receiving spaces are adapted in their shape to those of the rechargeable battery cells, for example cylindrically or cuboidally. Base side means that the relevant cell-supporting pillar is part of the holder base part. The rechargeable battery cells with their circumferential surface, typically their cylindrical lateral surface, can therefore be placed or supported in an axially and radially positionally secured manner against the circumferential side securing wall region of a base side cell supporting pillar or preferably of a plurality of adjacent base side cell-supporting pillars. This contributes in a structurally simple manner to reliable, play free holding of the rechargeable battery cells in the cell receiving spaces on the holder base part. A plurality of such base side cell supporting pillars is preferably provided. In addition, the base side cell supporting pillars can thereby prevent the rechargeable battery cells, if the latter are inserted first into the holder base part, from being undesirably able to pass or drop axially out of same before the holder cover part and the holder base part are completely mounted on each other. The positional securing of the respective rechargeable battery cell in the axial direction and in a radial, i.e. lateral, direction perpendicular thereto on the holder base part can be realized, depending on requirements, by force fitting and/or form fitting contact of the one or more adjacent, base side cell supporting pillars. The securing wall region is formed, for example, by a region of a pillar lateral surface of the cell-supporting pillars.

According to a further aspect of the invention, which can be provided additionally or alternatively to the abovementioned inventive aspect, the holder cover part, which is a component which is connectable to the holder base part opposite the latter, and which may correspondingly also be referred to as holder front side part or holder rear side part or holder upper side part or holder lower side part, has one or more cover side cell supporting pillars which extend axially from a cover plane of the holder cover part into the cell intermediate spaces and have a circumferential side securing wall region which is configured for abutting in an axially and radially position securing manner against a circumferential surface of rechargeable battery cells to be accommodated in the cell receiving spaces. Cover side merely means here that the relevant cell supporting pillar is part of the holder cover part. The rechargeable battery cells with their circumferential surface, typically their cylindrical lateral surface, can thus be placed or supported in an axially and radially positionally secured manner against the circumferential side securing well region of a cover side cell-supporting pillar or preferably of a plurality of adjacent cover side cell supporting pillars. This contributes in a structurally simple manner to a reliable, play free holding of the rechargeable battery cells in the cell receiving spaces on the holder cover part. A plurality of such cover side cell supporting pillars is preferably provided. In addition, the cover side cell supporting pillars can thereby prevent the rechargeable battery cells, if they are inserted first into the holder cover part, from being able to undesirably pass or drop out axially from same before the holder cover part and the holder base part are completely mounted on each other. The positional securing of the respective rechargeable battery cell in the axial direction and in a radial, i.e. lateral, direction perpendicular thereto on the holder cover part can be realized, depending on requirements, by force fitting and/or form fitting contact of the one or more adjacent cover side cell supporting pillars.

According to a further aspect of the invention, which can be provided additionally or alternatively to one or more of the abovementioned inventive aspects, the cell receiving spaces have a greater clear receiving width in a central region of the array than in a peripheral region of the array. It goes without saying that this property, like other properties mentioned here of the cell holder structure, relates, unless stated otherwise or unless readily understood by a person skilled in the art, to a preassembly state in which the rechargeable battery cells have not yet been fitted into the cell receiving spaces or any rate the holder cover part and the holder base part are not yet connected to each other and the rechargeable battery cells are held supported in the cell receiving spaces. This measure can advantageously contribute to holding rechargeable battery cells in the cell receiving spaces in the central region of the array with an approximately identical supporting force or contact pressure force, i.e. approximately identical supporting pressure or contact pressure force, as in the peripheral region of the array when, during the mounting of the holder cover part on the holder base part, slight lateral deformations of the cell supporting pillars occur in the cell receiving spaces because of the rechargeable battery cells coming to bear against said cell supporting pillars. Such slight lateral deformations of the cell supporting pillars could otherwise lead to higher force loadings arising for rechargeable battery cells in the central region of the array, because of the supporting/contact pressure of the cell supporting pillars, than for rechargeable battery cells in the peripheral region of the array. This effect is counteracted by a somewhat larger clear receiving width by the cell receiving spaces being made available to the rechargeable battery cells in a central region of the array than for the rechargeable battery cells in the peripheral region of the array.

In a development of the invention, at least one of the base side cell supporting pillars widens conically in the direction of the base plane of the holder base part, at least in an axial partial region which contains the securing wall region of said pillar. This measure can facilitate a centred insertion of the rechargeable battery cells into the part of the cell receiving spaces that is provided by the holder base part before the holder cover part is mounted on the holder base part, and/or can facilitate the position securing lying of the base side cell supporting pillar against the circumferential surface of the rechargeable battery cell. A plurality of and, more preferably, all of the base side cell supporting pillars are preferably thereby configured conically in the relevant axial partial region.

In a development of the invention, at least one of the cover side cell supporting pillars is widened conically in the direction of the cover plane of the holder cover part, at least in an axial partial region containing the securing wall region of said pillar. This measure can facilitate a centred insertion of the rechargeable battery cells into the part of the cell receiving spaces that is provided by the holder cover part before the holder cover part is mounted on the holder base part, and/or can assist the position securing lying of the cover side cell supporting pillar against the circumferential surface of the rechargeable battery cell. A plurality of and, more preferably, all of the cover side cell supporting pillars are preferably thereby configured conically in the relevant axial partial region.

In a development of the invention, at least one of the base side cell supporting pillars and/or of the cover side cell supporting pillars is of dome shaped or frustoconical design at least in a pillar end region containing the securing wall regions. This measure may be of advantage in terms of manufacturing and functionally. Preferably, a plurality of the base side cell supporting pillars and/or a plurality of the cover side cell supporting pillars and, more preferably, all of the base side cell supporting pillars and/or all of the cover side cell-supporting pillars are thereby of dome shaped or frustoconical design at their relevant pillar end region. The conicity of the frustoconical shape or dome shape can facilitate the fitting of the rechargeable battery cells into the cell receiving spaces and can promote supporting of the rechargeable battery cells with their circumferential surface in a reliably axially and radially position securing manner on the associated circumferential side securing wall region of the respective base side and/or cover side cell supporting pillar.

In a development of the invention, at least one of the base side cell supporting pillars has a hollow pillar structure, and its securing wall region is exposed towards the base plane of the holding base part. This realization of the pillar advantageously permits a radially elastic yielding of the securing wall region unobstructed by the base plane of the holder base part, as a result of which, when a rechargeable battery cell is inserted into an adjacent cell receiving space, the securing wall region can be pressed away in a radially elastic manner by the rechargeable battery cell and is then positioned with a restoring pressure against the circumferential surface of the rechargeable battery cell. This promotes the provision of a comparatively high position securing force against the rechargeable battery cell moving away axially and radially from the holder base part.

In a development of the invention, at least one of the cover side cell supporting pillars has a hollow pillar structure, and its securing wall region is exposed towards the cover plane of the holder cover part. This realization of the pillar advantageously permits a radially elastic yielding of the securing wall region unobstructed by the cover plane of the holder cover part, as a result of which, when a rechargeable battery cell is inserted into an adjacent cell receiving space, the securing wall region can be pressed away in a radially elastic manner by the rechargeable battery cell and is then positioned with a restoring pressure against the circumferential surface of the rechargeable battery cell. This promotes the provision of a comparatively high position securing force against the rechargeable battery cell moving away axially and radially from the holder cover part.

In a development of the invention at least one of the base side cell supporting pillars has, in its securing wall region, a bearing projection protruding radially towards one of the cell receiving spaces, and/or at least one of the cover side cell supporting pillars has, in its securing wall region, a bearing projection protruding radially towards one of the cell receiving spaces. Preferably, a plurality of and, more preferably, all of the base side cell supporting pillars and/or of the cover side cell supporting pillars are provided with one or more of the bearing projections protruding radially from the securing wall region. The bearing projection can very advantageously assist or reinforce the axially and radially position securing lying of the relevant securing will region against the inserted rechargeable battery cell. For example, in corresponding realizations, it can be wedged or latched or clamped or interlocked to a bearing edge on the circumference of the rechargeable battery cell and can thereby hold the rechargeable battery cell in a manner very readily secured against moving out axially.

In a development of the invention, in order to provide the larger clear receiving width of the cell receiving spaces in the central region of the array in relation to the smaller clear receiving width of the cell receiving spaces in the peripheral region of the array, at least one of the base side cell supporting pillars and/or of the cover side cell supporting pillars has a greater radial dimension in the peripheral region of the array than at least one of the base side cell supporting pillars and/or of the cover side cell supporting pillars in the central region of the array.

This measure can be realized structurally in a relatively simple manner, for example by a correspondingly different configuration of the outside diameter of the relevant cell supporting pillars. Preferably, a plurality of the base side cell supporting pillars and/or a plurality of the cover side cell supporting pillars and, more preferably, all of the base side cell supporting pillars and/or all of the cover side cell supporting pillars are thereby formed in the central region of the array with a smaller outside diameter than the base side and/or cover side cell supporting pillars in the peripheral region of the array. The variation in diameter can be selected, depending on requirements, depending on the distance of the cell supporting pillar from a centre point of the array or from a peripheral edge of the array in one or a few steps or virtually continuously.

In a refinement of the invention, said measure is realized in that the bearing projection of at least one of the base side cell supporting pillars and/or of the cover side cell supporting pillars has a greater radial dimension in the peripheral region of the array than the bearing projection of at least one of the base side cell supporting pillars and/or the cover side cell supporting pillars in the central region of the array. Preferably, a plurality of the base side cell supporting pillars and/or a plurality of the cover side cell supporting pillars and, more preferably, all of the base side cell supporting pillars and/or all of the cover side cell supporting pillars are thereby formed in the central region of the array with the bearing projection of smaller radial extent than the base side and/or cover side cell supporting pillars in the peripheral region of the array. The variation in the radial dimension of the bearing projection can be selected, according to requirements, depending on the distance of the cell supporting pillar from a centre point of the array or from a peripheral edge of the array in one or a few steps or virtually continuously.

Preferably, a plurality of, and, more preferably, all of the base side cell-supporting pillars and/or of the cover side cell supporting pillars are provided in the peripheral region of the array with one or more of the bearing projections protruding radially from a pillar lateral surface. In addition, preferably a plurality of and, more preferably, all of the base side cell supporting pillars and/or of the cover side cell-supporting pillars in the central region of the array are provided with one or more of the bearing projections which protrude radially from the pillar lateral surface and the radial dimension of which is smaller than that of the bearing projection or bearing projections of the one or more cell supporting pillars in the peripheral region of the array. Alternatively, the respective base side and/or cover side cell-supporting pillar in the central region of the array does not have any such bearing projection. The bearing projections can be realized, for example, as punctiform projections or humps or lugs or as linear webs running on the circumferential side and/or axially.

In a development of the invention, at least one of the base side cell-supporting pillars has a greater length than the cover side cell supporting pillars. Preferably, a plurality of, and, more preferably, all of the base side cell supporting pillars have a greater pillar length than the cover side cell supporting pillars. The greater length of the base side cell supporting pillars in comparison to the cover side cell supporting pillars can promote the mounting process by being able to act over a correspondingly large axial length as side boundaries when the rechargeable battery cells are placed into the holder base part, more precisely into the part of the cell receiving spaces that is provided by the holder base part, before the holder cover part is then mounted on the holder base part. Their greater length makes it possible for the base side cell supporting pillars to securely hold the loosely inserted rechargeable battery cells securely in the respective cell receiving space in said preassembly state as long as the holder base part is not tilted excessively.

According to a further aspect of the invention, which can be provided additionally or alternatively to each of the abovementioned inventive aspects, the cell receiving spaces are configured for receiving the rechargeable battery cells in an identical position axially irrespective of the pole direction, and at least one plate like cell connector is provided which can be mounted on the holder base part or on the holder cover part and in each case has at least one positive pole contact zone and at least one negative pole contact zone, wherein the positive pole contact zone and the negative pole contact zones protrude at a differing contact zone height from a plate plane of the cell connector.

This measure permits a highly advantageous realization of a rechargeable battery cell arrangement, which is connected electrically in parallel and in series in a desired manner, by using said cell holder structure. For this purpose, the rechargeable battery cells can already be introduced in groups with opposed pole directions into the cell receiving spaces, which are suitably configured for this purpose, in such a manner that they are accommodated there in a substantially identical axial position, i.e. all of the rechargeable battery cells at their axial end edges have substantially the same axial position irrespective of whether they point, for example, with their plus pole in the direction of the holder base part or in the direction of the holder cover part. By the differing contact zone height of its positive or negative pole contact zone, the plate like cell connector takes account of the fact that, in the typical rechargeable battery cells used in this case, the plus pole ends at a different axial distance from the facing axial end edge of the rechargeable battery cell than the minus pole.

The plus pole of the rechargeable battery cell often protrudes axially further over the axial end edge of the rechargeable battery cell than the minus pole, and therefore, in the case of two rechargeable battery cells which are accommodated in their cell receiving spaces in an identical position axially, but with an opposed direction of polarity, the plus pole of the one rechargeable battery cell protrudes axially on the relevant side over the minus pole of the other rechargeable battery cell. The plate like cell connector can compensate for this by its differing contact zone heights of the positive pole contact zone, which serves for the electrical contact connection to a rechargeable battery cell plus pole, and the negative pole contact zone, which serves for the electrical contact connection to a rechargeable battery cell minus pole.

In a development of the invention, a plurality of structurally identical cell connectors is provided, said cell connectors being able to be mounted either on the holder base part or on the holder cover part. This means that structurally identical cell connectors can be used for mounting on the holder base part and on the holder cover part, which renders the manufacturing of cell connectors which can be mounted specifically only on the holder base part or only on the holder cover part superfluous.

In a development of the invention, the respective cell connector can be mounted on the holder base part or on the holder cover part by means of a clamping and/or snap connection. This constitutes an advantageously simple and functionally reliable connection of the cell connector on the holder base part or on the holder cover part.

In a development of the invention, corresponding positioning marks are provided on the cell connector, on the one hand, and on the holder base part and/or on the holder cover part, on the other hand, for positionally correctly mounting the cell connector on the holder base part or on the holder cover part. This simplifies the attaching of the cell connector to the holder base part or to the holder cover part by the corresponding positioning marks preventing an erroneous positioning of the cell connector during the mounting.

The rechargeable battery pack according to the invention comprises a cell holder structure according to the invention and a plurality of rechargeable battery cells held by the cell holder structure. The rechargeable battery cells are held securely and in a play free manner in said cell holder structure, as explained above. The rechargeable battery pack is thereby in particular also suitable for applications in which the rechargeable battery pack may be subjected to shaking or impact effects. In particular, the rechargeable battery pack is suitable for the electrical energy supply of hand held electrical devices, such as electrically driven garden and forest processing devices which are portable or are carried on the back or are guided on the ground.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

