GB2483156A

GB2483156A - Handtool Battery Housing

Info

Publication number: GB2483156A
Application number: GB1114468.0A
Authority: GB
Inventors: Wolf Matthias; Josef Baumgartner; Rainer Glauning
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-08-24
Filing date: 2011-08-22
Publication date: 2012-02-29
Anticipated expiration: 2031-08-22
Also published as: DE102010039710A1; DE102010039710B4; GB201114468D0; CN102376923A; GB2483156B; CN102376923B

Abstract

A handtool battery housing comprises an integral housing element (12) having at least one crumple zone (14). The crumple zone (14) has an outer wall (16) and an inner wall (18) spaced from the outer wall (16).

Description

HANDTOOL BATTERY HOUSING

The present invention relates to a handtool battery housing.

A handtool motor battery housing with an integral housing element having a crumple zone is known, but there is scope to improve the effectiveness of such a zone by relatively simple and economic constructional measures.

According to the present invention there is provided a handtool battery housing comprising an integral housing element having a crumple zone, the crumple zone comprising at least one outer wall and at least one inner wall spaced from the at least one outer wall.

By the term "integral" there is to be understood, for example, connected at least by material couple, such as by a welding process, a g'uing process, an injection-moulding process and/or any process appearing feasible to the expert, and/or formed in one piece such as by, for example, production as a casting and/or production in a single-component or multi-component injection-moulding process and/or from a solid blank. By "crumple zone" there is to be understood, especially, a region of the housing element which is provided for the purpose, in the case of a shock acting on the crumple zone particularly with a defined maximum energy, of absorbing at least a part of the energy by, for preference, resilient deformation. The defined maximum shock energy corresponds with, for example, the energy resulting from dropping a handtool motor battery with the housing and a battery unit, which is secured by and intended for combination with the housing, from a height of at least one metre, preferably two metres. By "provided" there is to be understood, for example, specially designed and/or arranged. By a "outer waJJ" there is to be understood, for example, a wall of the housing element which on at least one straight line extending from a centre point of a battery receiving region of the housing element in only one direction is arranged at a greater spacing than the inner wall of the housing element on the straight line. By an "outer wall" and an "inner wall spaced from the outer wall" there is to be understood, for example, two regions of the housing element which on the straight line are spaced from one another by a space which is not filled out by the housing element and, particularly, are spaced by more than 0.5 millimetres, preferably more than 1 millimetre and particularly preferably more than 2 millimetres.

Advantageously, the housing element surrounds the space on at least one plane through 3600. Through the design of the housing in accordance with the invention it is possible to achieve protection of the battery unit against mechanical loads such as arise due to dropping. In particular, it is possible to avoid breakage of connections between battery cells due to the loads, detaching or shifting of other elements, and deformation of and damage to battery cells due to a mechanical deformation of the housing in the event of loading.

In a preferred embodiment the housing element is provided for the purpose of fastening a battery unit, whereby the battery unit may be able to be fastened in particularly stable manner and at the same time protected. In particular, movement of battery cells relative to one another in the case of a load due to dropping can be prevented, which reduces the probability of damage to interconnections of the cells. Moreover, an efficient cooling may be possible in a constructionally simple manner. The term "battery unit" signifies, for example, a device for rechargeable storage of electrically retrievable energy. Such a battery unit preferably comprises battery cells, particularly lithium cells. Alternatively or additionally the battery unit could comprise at least one power capacitor, a fuel cell and/or another chargeable energy store appearing feasible to the expert. By "fasten" it is to be understood, for example, that the housing element comprises at least one means provided for the purpose of exerting a fastening force on the battery unit. The housing element preferably comprises mechanically positive coupling means which in at least one operating state exert a fastening force on the battery unit, preferably on battery cells of the battery unit. Alternatively or additionally, the housing element could comprise detent means, a material-coupling connection and/or another means for fastening the battery unit. The housing element preferably fastens the battery unit free of play, i.e. the battery unit is substantially immovable relative to the housing element at least in the case of normal operation and preferably in the case of a load due to dropping, for example the battery unit moves relative to the housing element less than 1 millimetre, preferably less than 0.5 millimetres, particularly preferably less 0.1 millimetres. The housing element preferably fastens the battery unit, for example individual battery cells, by a bias, especially so that in an operationally ready state the housing element constantly exerts directly andlor indirectly a fastening force on the battery unit.

For preference the crumple zone is arranged along an edge region of the housing element, whereby a particularly effective protection against impact-like loads and at the same time an effective heat dissipation are possible in a constructionally simple manner. By " edge region" there is to be understood, for example, an area region which is convex along a path length and which interconnects two at least substantially uncurved surfaces, particularly two outer surfaces of side walls of the housing element. The edge region preferably has on the path length between at least two defined points, which are preferably spaced apart on the path length by less than 15 millimetres, a stronger curvature than at least one of the two outer surfaces on a path of corresponding length. The curvature is preferably more than 30 degrees, particularly preferably more than 60 degrees. The expression "along an edge region" signifies, for example, that the crumple zone is arranged at a spacing from an edge section straight line of the edge region of, at least in part, less than 50 millimetres, preferably less than 20 millimetres, particularly preferably less than 10 millimetres. The edge section straight line can in that case be formed by a section line of two median main length planes of the side walls which are connected by way of the edge region.

Additionally or alternatively the crumple zone can be arranged at a corner region of the housing element, whereby an effective protection against impact-like loads and at the same time a particularly effective heat dissipation may be possible in a constructionally simple manner. By "corner region" there is to be understood, for example, a convex area region which connects together three or more at least substantially uncurved surfaces, particularly at least three outer surfaces of side walls of the housing element. The edge region preferably has on path lengths between at least three defined points, which are preferably spaced apart on the path lengths by less than 15 millimetres, a stronger curvature than at least one of the two outer surfaces on paths of corresponding length.

The curvature is preferably more than 30 degrees, particularly preferably more than 60 degrees. By the expression "at a corner region" there is to be understood, for example, that the crumple zone is arranged at a spacing from a corner section point of the corner of, at least in part, less than 50 millimetres, preferably less than 20 millimetres, particularly preferably less than 10 millimetres. The corner section point can in that case be formed by a section point of two median main length planes of the side walls, an upper side and/or a lower side which are connected by way of the edge region.

The housing element preferably has at least one side wall constructed at least for the major part to be free of crumple zone, whereby a particularly advantageous cooling of the battery can be achieved. By "side wall" there is to be understood, for example, a region of the housing element which extends between edge regions of the housing. An outer surface of the side wall is preferably curved between at least two defined points -which are spaced from one another by, especially, more than 25 millimetres -by less than 45 degrees, preferably less than 15 degrees. The side wall preferably has a surface which is larger than 5 square centimetres, preferably larger than 10 square centimetres. The housing is preferably substantially block-shaped, for example with at least four side walls and also an upper side with a handtool motor coupling device and a lower side. By the expression "at least for the major part free of crumple zone" there is to be understood, for example, that over at least 50%, preferably at least 75%, of an area of the side wall on a normal of the area, which intersects the side wall and the battery unit, the side wall is interrupted between the housing element and the battery unit by a special region absorbing shock energy. The region of the side wall is preferably constructed to be solid and/or, especially, heat conductive, for example by an injection-moulded metal element.

With particular advantage the side wall can be formed to be integral on a normal of the side wall between a surface of the side wall and the battery unit. Advantageously, the side wall is provided for the purpose of dissipating heat from the battery and, especially at a surface of the side wall which can be constructed as a cooling body with cooling ribs.

In a preferred embodiment the crumple zone has at least one air chamber, whereby a lighter and more effective protection against impact-like loads can be made possible in a constructionally simple manner. By "air chamber" there is to be understood, for example, a region which is filled with air and which is preferably bounded by the outer wall and the inner wall. With particular advantage the air chamber is completely enclosed by the housing element on at least one plane, especially perpendicularly to the main length of the air chamber. Alternatively or additionally to the air chamber an easily compressible material, for example a foam material, could be arranged between the outer wall and the inner wall.

For preference, the air chamber also serves the purpose of conducting an air flow, whereby the battery unit can be cooled. The air chamber preferably comprises two mutually spaced-apart openings through which air can be conducted into and can exit from the air chamber.

The housing preferably comprises an electrical functional element arranged at least partly in the air chamber, whereby a simple construction of small volume is possible. By "electrical functional element" there is to be understood, for example, a cable, a sensor, an electrical contact, art REID element, an electronic system and/or any other electrical functional element.

A preferred embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which Fig.1 is a perspective view of a handtool motor battery with a handtool motor battery housing embodying the invention; Fig. 2 is a perspective sectional view of part of the housing of Fig. 1, with included battery; and Fig. 3 is a sectional plan view of the housing part shown in Fig. 2.

Referring now to the drawings, Figs. 1 to 3 show a handtool motor battery 32 with a handtool motor battery housing 10 and a battery unit 20. The housing 10 comprises a lower integral housing element 12, an upper integral housing element 12' and a housing outer element 34. The housing 10 is of substantially block-shaped construction.

The housing outer element 34 is formed substantially from a rubber-like material. It encloses the lower housing element 12 along edge regions 22 of the lower housing element 12. Side walls 26 of the lower housing element 12 are not enclosed. The housing outer element 34 is fastened to the lower housing element 12 by means of a mechanically positive couple. For this purpose the housing outer element 34 has moulded portions 36 which in a mounted state are arranged in recesses 38, 38' of the lower housing element 12. Two of the moulded-on portions 36' detent in recesses 38' of the lower housing element 12.

The housing elements 12, 12' are substantially made of polyethylene, in particular from a high-density polyethylene (PE-HD). The lower housing element 12 and the upper housing element 12' are firmly connected together, in particular, screw-connected. Together they completely enclose the battery unit 20. The housing elements 12, 12' mechanically positively fasten the battery unit 20. The housing 10 additionally has shape elements 40.

The elements 40 exert on the battery unit 20 a bias which supports them at the housing elements 12, 12'. The battery unit 20 is thus fastened free of play in the housing elements 12, 12'. The battery unit 20 comprises a plurality of battery cells 42, preferably lithium cells. The housing elements enclose the battery cells 42 on a plane perpendicular to a main length direction of the battery cells 42 by more than 180 degrees.

The lower housing element 12 and the upper housing element 12' each have a crumple zone 14. Alternatively, only the lower housing element 12 has a crumple zone 14. The crumple zones 14 are arranged along edge regions 22 and at corner regions 24 of the housing elements 12. The crumple zones 14 are each formed by an outer wall 16 and an inner waIl 18 spaced from the outer wall 16, with air chambers 28 between the walls 16, 18. The air chambers 28 have, on a plane perpendicular to a length direction of the edge regions 22, a substantially triangular cross-section. Alternatively or additionally the walls 16, 18 could be oriented on the plane parallel to one another. Each air chamber 28 has openings, which are not illustrated in detail, the air chamber 28 thus also serving the purpose of conducting an air flow for cooling the battery unit.

The handtool motor battery 32 has a handtool motor coupling device 44 and an electronic system (not illustrated). The coupling device 44 is arranged at an upper side 46 of the housing 10. The electronic system is arranged between the battery unit 20 and the coupling device 44. The upper housing element 12' encloses, protects and fastens the electronic system.

The housing 10 comprises an electrical functional element 30 which is illustrated in Figs. 2 and 3. The element 30 can be an electrical line, which connects the electronic system with contacts (not shown), at a lower side 48 of the housing 10. In that case the element 30 runs through one of the air chamber 28. It occupies less than 20% of the cross-section of the air chamber 28. The element 30 is thus arranged partly in the air chamber 28.

The lower housing element 12 has side walls 26 which are free of crumple zone. At an outer side, the side walls 26 have cooling ribs 50. The housing elements 12, 12' are constructed integrally, i.e. solidly, between the cooling ribs 50 and the mechanically positive couple of the housing elements 12, 12' with the battery unit 20. The ower side 48 of the lower housing element 12 is similarly of solid construction.

Anedgesectlonstraightiine52cttwoOftheSideWails26 isehown in Flg.4. Thelma 52 Is bmed by a section IS of two median main length planes 54 which are connected by way of the edge region 22.

Claims

CLAIMS1. A handtool battery housing comprising an integral housing element having a crumple zone the crumple zone, comprising at least one outer wall and at least one inner wall spaced from the at least one outer wall.
2. A housing according to claim 1, wherein the housing element is provided for the purpose of fastening a battery unit.
3. A housing according to claim 1 or claim 2, wherein the crumple zone is arranged along an edge region of the housing element.
4. A housing according to any one of the preceding claims, wherein the crumple zone is arranged at a corner region of the housing element.
5. A housing according to any one of the preceding claims, wherein the housing element has at least one side wall which is formed for at least the major part to be without a crumple zone.
6. A housing according to any one of the preceding claims, wherein the crumple zone comprises at least one air chamber.
7. A housing according to claim 6, wherein the air chamber is so arranged as to be able to conduct an air flow.
8. A housing according to claim 6 or claim 3, comprising an electrical functional element arranged at least partly in the air chamber.
9. A handtool motor battery with a battery housing according to any one of the preceding claims.