DE102011109243A1 - Battery i.e. high volt battery, for e.g. electric vehicle, has wing-like limiting arm arranged to form stop with battery housing for limiting opening path of closure element relative to battery housing - Google Patents

Abstract

The battery has a closure element (3) arranged to open and close a plate spring-loaded valve (1) and moved with respect to a battery housing. A spring element (2) is connected to the closure element that comprises a leaf-spring-like arm (2.2) and a wing-like limiting arm (2.3). The spring-like arm is supported to bias of the closure element opposite to the battery housing. The wing-like limiting arm is arranged to form a stop with the battery housing for limiting an opening path of the closure element relative to the battery housing.

Description

The invention relates to a battery according to the preamble of patent claim 1.

From the prior art spring-loaded differential pressure valves are known, which are arranged on battery housings. If the internal pressure in the interior of the battery case increases, the differential pressure valve opens so that gas can escape and the internal pressure is lowered. Subsequently, the differential pressure valve is automatically closed again due to the spring load.

From the DE 10 2007 063 191 A1 The applicant is aware of a battery for use in a vehicle, which has a device for reducing the internal pressure, which is designed as a leaf spring-loaded valve. After a reduction in the internal pressure, the valve closes automatically.

The invention is based on the object of specifying a battery, in particular for use in a vehicle, which has improved protection against damage.

The object is achieved by a battery having the characteristic features of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

A battery, which is particularly suitable for use in a vehicle, is arranged in a battery housing, on which a device for reducing an internal pressure is arranged. The device for reducing the internal pressure is designed as a leaf spring-loaded valve which automatically opens and / or closes in dependence on the pressure difference of an internal pressure to an external pressure. A closure element is movably mounted with respect to the battery housing for opening and closing the valve. According to the invention, a spring element, which is connected to the closure element, at least one leaf spring-like spring arm and at least one wing-like limiter. The spring arm is supported for biasing the closure element relative to the battery case. The limiting arm is arranged such that it forms with the battery housing a stop for limiting an opening path of the closure element relative to the battery housing.

The valve with the leaf spring-like spring arm and the wing-like limiting arm claimed for correct functioning only a small space depth. Therefore, the valve is particularly suitable to be arranged on a battery case, in which the available space is limited. This is especially true when using the battery in the vehicle.

Since batteries heat up strongly in the event of a high charge and / or discharge current, in particular in the event of a short circuit, a high internal pressure builds up inside the battery housing, which can lead, for example, to bursting of the battery housing. The valve advantageously makes it possible to reduce an increased internal pressure, so that the risk of destroying the battery is at least reduced, in particular in the case of short circuits. Babel is limited to the opening travel of the valve, so that the likelihood that a harmful liquid, in particular spray water with the valve open, penetrates into the battery housing, at least reduced.

Preferably, the battery is designed as a vehicle battery and has a plurality of individual cells, which are interconnected in a cell combination. Particularly preferably, the battery is a high-voltage battery and has a plurality of individual cells with lithium-ion cell chemistry, so that the battery can serve as energy storage for an electric drive unit of the vehicle. Accordingly, the vehicle is an electric or hybrid vehicle.

The terms battery and battery housing used are to be interpreted generally and describe an arrangement with at least one electrochemical cell and a housing surrounding this arrangement. In particular, it is provided to arrange the valve on the housings of the individual cells of the cell assembly in order to reduce an internal pressure prevailing therein and to counteract any damage to the corresponding individual cell at an early stage. Accordingly, the housing of a single cell or that of a cell assembly, which comprises of the plurality of single cells, generally referred to as a battery case.

Preferably, the spring element on two oppositely disposed spring arms and two oppositely arranged stop arms. This construction is simple and inexpensive to implement and has improved stability.

The closure element is preferably substantially plate-shaped. The spring element is connected to a central retaining lug of the closure element and exerts a force on the closure element even in the closed state of the valve, so that penetration of moisture is reduced. Thus, corrosion of metallic components of the battery can be avoided.

Preferably, the closure element in a peripheral edge region on a seal, which rests in the closed state of the valve on the battery case for sealing the battery case. The seal preferably has a profile structure, which faces the battery housing, so that penetration of liquid into the battery housing is largely avoidable.

In preferred embodiments of the invention, the closure element has at least one opening which is closed by means of a closure means. In this case, the closure means is formed by a gas-permeable and liquid-tight material or composite material. This also allows a pressure equalization with only a slight pressure difference between internal and external pressure, which is not sufficient for the automatic opening of the valve. Such a small pressure difference may be caused, for example during operation of the battery of a normal charging and / or discharge. The sealed by means of the closure means openings define in particular air inlet and outlet of the battery housing for controlled pressure equalization. Fehlluftströmungen, which are caused for example by guided through the battery case cable insulation or housing seals can thus be avoided.

Advantageously, it can thus be avoided that thin-walled battery housings inflate or occur at a slight pressure difference. As a result, in particular material fatigue is at least reduced and thus extends the life of the battery.

An internal pressure slowly building up inside the battery housing can be compensated early via the gas-permeable closure means. Thus, in such cases, the internal pressure does not reach a limit necessary for opening the spring-loaded valve. The valve remains closed and the pressure equalization takes place via the closure means, so that penetration of particles or liquids into the battery housing is largely precluded.

The pressure compensation function at low pressure differences is advantageously integrated into the valve, so that an additional space requirement is avoided.

Preferably, the closure means is positively, positively and / or materially connected to the closure element, so that a liquid-tight seal of the openings in the closure element can be ensured.

The spring element of the valve preferably serves for frictional connection of the closure means to the closure element, so that further components and additional space requirements are avoided. This reduces in particular the manufacturing cost of the battery.

Particularly preferably, the material and / or the composite material of the closure means is hydrophobic and / or oleophobic. Such water and / or oil repellent materials or composite materials additionally reduce the risk that corresponding polar and / or non-polar liquids penetrate into the battery housing. For this purpose, in particular the material of the closure means may have corresponding coatings.

The permeability of the closure means for gases and liquids is predetermined by the material and / or the material composite from which the closure means is formed. In particular plastic materials are suitable for this purpose. For example, the closure means is made of a polyethylene, a polyethersulfone and / or a polytetrafluoroethylene and / or a combination of these materials. The materials mentioned have suitable properties, such as pore size or penetration resistance to water, which can be selected according to the specific application. In addition, the permeability of the closure element can also be predetermined over its thickness. This allows a variety of applications, since the permeability of the closure element and thus the required pressure equalization pressure differential between the inner and outer pressure largely over the properties, in particular the material properties of the closure means can be predetermined.

In a preferred embodiment of the invention, the closure means is designed as a membrane which can be glued to the closure element in a particularly simple manner. Furthermore, such a film-like membrane can be produced particularly inexpensively, for example, as a roll product.

Embodiments of the invention will be explained in more detail below with reference to a drawing.

Showing:

1 a leaf spring-loaded valve according to a first embodiment of the invention in a perspective view,

2 the valve of the first embodiment in the closed state in a sectional view,

3 the valve of the first embodiment in the open state in a sectional view,

4 a leaf spring-loaded valve according to a second embodiment of the invention in an exploded view,

5A and 5B Embodiments of a gas-permeable and liquid-tight closure means for the valve of the second embodiment,

6 the valve of the second embodiment in a perspective view,

7 a leaf spring-loaded valve according to a third embodiment in an exploded view,

8th the valve of the third embodiment in a perspective view,

9 a leaf spring-loaded valve according to a fourth embodiment in an exploded view,

10 the valve of the fourth embodiment in a perspective view,

11 a leaf spring-loaded valve according to a fifth embodiment in an exploded view,

12 the valve of the fifth embodiment in a perspective view,

13 the valve of the sixth embodiment in a perspective view,

14 the valve of the sixth embodiment in a plan view and

15 the closure element of the valve according to the sixth embodiment.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows a leaf spring-loaded valve 1 according to a first embodiment, which is intended to be arranged on a battery case B. The valve 1 has a spring element 2 on, which is preferably made as a one-piece stamped part of hardened or unhardened spring steel. A substantially plate-shaped closure element 3 is with the spring element 2 connected. For this purpose, the closure element 3 a central holding nose 3.1 on which of cutting claws 2.1 of the spring element 2 are held positively.

The spring element 2 has two oppositely disposed and elastically deformable spring arms 2.2 each having an outwardly bent first end 2.2.1 have, that is designed to lie on the battery housing B on the inside and so the valve 1 to be supported on the battery case B. By means of the spring arms 2.2 is the closure element 3 with respect to the battery case B for opening and / or closing the valve 1 movably mounted.

The spring element 2 has two wing-like limiter arms projecting radially outward 2.3 on, which are adapted to strike the inside of the battery case B, when the valve 1 is open. The delimiting arms 2.3 thus limit an opening path of the movably mounted closure element 3 , The valve is stressed 1 with the spring arms 2.2 and the limiter arms 2.3 only a small space depth, with a defined stroke or opening travel of the closure element 3 can be specified. For liquid and / or gas-tight sealing of the closure element 3 opposite the battery case B is in a peripheral edge region 3.2 a seal 4 arranged, which has a suitable ribbed profile structure.

2 shows the valve 1 of the first embodiment in a sectional view. The valve 1 is disposed on the battery case B and is in a closed state in which the circumferential seal 4 tight against the battery case B. When closed, the limiting arm is located 2.3 at a distance A to the battery case B.

3 shows the valve 1 of the first embodiment in the open state in a sectional view. The limiting arm 2.3 lies on the inside of the battery case B, so that correspondingly the closure element 3 is spaced by the distance A from the battery case B.

The discharging or loading of the battery housing B arranged in the battery can be accompanied by a strong evolution of heat. In this case, a strong pressure can build up inside the battery, especially in the interior of individual cells of the battery. If the internal pressure in the battery housing B reaches a limit in relation to the external pressure, the valve opens 1 automatically, so that the internal pressure is degradable. In the open state is the spring element 2 cocked, leaving the valve 1 automatically closes again when the internal pressure falls below the limit. Thus, the limit that is necessary is around the valve 1 to open or close on the bias of the spring element 2 predetermined.

In addition, on the battery case B, a not-shown projecting flange may be formed, which is the plate-shaped closure element 3 in the peripheral edge area 3.2 surrounds, allowing intrusion of spray water when the valve is open 1 at least reduced.

4 shows a second embodiment of the valve 1 in an exploded view. The valve 1 of the second embodiment and the embodiments described below largely correspond to the design of the first embodiment.

This in 4 to 6 illustrated closure element 3 of the valve 1 has a variety of openings 3.3 on, by means of closure means 5 are closed.

Embodiments of the in the openings 3.3 positively inserted closure means 5 are in detail in the 5A and 5B shown. The closure means 5 is made of a material that is gas-permeable and at the same time liquid-tight. For example, the closure means is formed of a plastic material such as polyethylene, a polyethersulfone or a polytetrafluoroethylene. Preferably, the material of the closure means 5 hydrophobic and / or oleophop, allowing penetration of polar and / or non-polar liquids into the battery case B through the openings 3.3 at least reduced.

According to various embodiments, the material of the closure means 5 a penetration resistance to water of 1 to 6 meters of water, more preferably from 1 to 1.5 meters of water. In this case, 1 meter of water column under normal conditions corresponds to an equivalent pressure of about 9.81 kPa or 0.981 bar.

Through the openings 3.3 is achieved that even small pressure differences between the prevailing inside the battery case B internal pressure and the external pressure can be compensated. In this case, the pressure difference is below the limit, so that the valve 1 remains closed. Correspondingly small pressure differences can be caused, for example, by changes in air pressure. It is understood that even to compensate for such small pressure differences, a corresponding threshold must be exceeded or fallen below. This minimal pressure difference is necessary to a gas, in particular air through the material of the closure means 5 to press and thus specifiable via appropriate material parameters. In particular, the threshold value is the pore size of the material of the closure means 5 and determines its thickness D.

The closure means 5 is in the opening of the closure element 3 pressed positively. In addition, the closure means 5 with the closure element 3 cohesively, in particular by means of a bond to be connected. According to a preferred embodiment, the closure means 5 as a rivet in the opening 3.3 caulked, in particular hot staked installed. The closure element 3 is made of metal, for example, so that the openings 3.3 already during the forming thermoforming of the closure element 3 can be formed.

According to preferred embodiments, the closure means 5 at least one sealing flange at the end 5.1 on. The sealing flange 5.1 in the opening 3.3 introduced closure means 5 lies to seal the opening 3.3 positively on the inside or outside of the closure element 3 at. 5B shows an embodiment with two end faces arranged sealing flanges 5.1 , which are designed according to the inside and outside of the closure element 3 for sealing the opening 3.3 to rest.

6 illustrates the valve 1 of the second embodiment again in a perspective view.

7 shows a further, third embodiment of the valve 1 in an exploded view. In the third embodiment, the opening 3.3 in the area of the retaining nose 3.1 arranged, which may in particular have a corresponding central bore. It is understood that the opening 3.3 in another suitable way in the closure element 3 can be introduced. Furthermore, in particular, the geometric Gestallt the opening 3.3 and accordingly, the opening 3.3 closing closure means 5 merely exemplified and may have other suitable geometric shapes.

8th illustrates the third embodiment of the valve 1 in a perspective view. The closure element 3 points in the area of the retaining lug 3.1 an increased space depth, so that accordingly introduced there closure means 5 Compared to the second embodiment may have an increased thickness D, which is associated with an increase in the penetration resistance to a liquid, in particular water.

9 shows a fourth embodiment of the invention in an exploded view. The valve shown 1 has four in the closure element 3 introduced openings 3.3 on, that of the outside arranged closure means 5 gas-permeable and liquid-tight, which has a cap-like shape. The closure means 5 has a circular disk-shaped base body 5.2 with a protruding and collar-shaped edge 5.3 on, which by means of a bond to the closure element 3 is attached. In this case, the circular disk-shaped base body 5.2 of the closure means 5 a correspondingly large radius, so that the four openings 3.3 the closure element 3 are sealed.

10 shows the valve 1 of the fourth embodiment for illustration again in a perspective view.

11 and 12 show a fifth embodiment of the valve 1 , The four in the closure element 3 introduced openings 3.3 are inside of the closure means 5 closed, with the closure element 3 is adhesively bonded. The closure means 5 has in the example shown here an annular base body 5.2 on, the four protruding bulges 5.4 are formed, the arrangement and the geometric shape of the openings 3.3 correspond. Each of the bulges 5.4 is positively in one of the openings 3.3 arranged and seals this liquid-tight. In addition, the closure means 5 inside with the closure element 3 bonded.

The valve 1 also exercises in the closed state by means of the spring arms 2.2 a pressure on the battery case B on. As the annular body 5.2 of the closure means 5 directly on the spring element 2 is applied, is the closure means 5 additionally frictionally with the closure element 3 pressed. The necessary force is from the spring element 2 exercisable. For uniform load distribution is in an alternative embodiment not shown in addition between the spring element 2 and the closure means 5 arranged a particular annular load distribution element that ensures a uniform contact pressure for adhesion.

In the 9 to 12 shown embodiments can be mounted very quickly and easily, since only a single and substantially planar closure means 5 to close all openings 3.3 is provided. This also reduces the assembly effort to the extent that corresponding adhesions can be performed over a large area or the arrangement and bonding of a plurality of smaller closure means 5 is avoided.

13 to 15 show a sixth embodiment of the invention. In the sixth embodiment, the shutter means 5 designed as a membrane which is permeable to gases and impermeable to liquids. The membrane is annular and formed by a composite material comprising plastic materials, for example polyethylene, polyethersulfone and / or polytetrafluoroethylene. The composite material may be, for example, a fabric comprising a combination of plastic materials.

Alternatively, the closure means 5 also be formed by a film which is made of a suitable material.

The membrane-like closure agent 5 inside covered in the closure element 3 introduced openings 3.3 and is with the closure element 3 bonded. In addition, there are two guard rings 6 concentric on the closure element 3 arranged, the edge side of the annular closure means 5 Cover to reduce the penetration of liquid.

Alternatively or additionally, the membrane-shaped closure means 5 also frictionally with the closure element 3 be connected. For this purpose, in particular a non-illustrated load distribution element is arranged that of the spring element 2 spring loaded and the closure element 3 lies flat. The load distribution element imparts a spring force to the closure means 5 so that this on the closure element 3 is evenly pressed.

To reduce the internal pressure in the battery case B, the valve 1 a defined opening way, by the stop of the Begrenzungsarms 2.3 bounded by the battery case B. The spring arms 2.2 of the valve 1 are formed leaf-spring-like. Due to the design, the valve 1 only a small space depth, so that this is particularly suitable to find a battery use.

Preferred embodiments additionally allow a pressure reduction with the valve closed 1 , These are openings 3.3 with closure means 5 sealed, which are gas-permeable and liquid-tight. Thus, penetration of a liquid, in particular water in the battery case B can be avoided. This functionality is in the valve 1 integrated, so that no additional space is needed.

LIST OF REFERENCE NUMBERS

1

Valve

2

spring element

2.1

cutting claw

2.2

spring arm

2.2.1

first end

2.3

limiting arm

3

closure element

3.1

retaining nose

3.2

border area

3.3

opening

4

poetry

5

closure means

5.1

sealing flange

5.2

body

5.3

edge

5.4

bulge

6

protective ring

A

distance

B

battery case

D

thickness

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007063191 A1 [0003]

Claims (10)

Battery, in particular for use in a vehicle, which is arranged in a battery housing (B) on which a device for reducing an internal pressure is arranged, which is designed as a leaf-spring-loaded valve ( 1 ) is executed, which automatically opens in dependence on the pressure difference of an internal pressure to an external pressure and / or closes, wherein a closure element ( 3 ) for opening and closing the valve ( 1 ) is movably mounted relative to the battery housing (B), characterized in that a spring element ( 2 ), which with the closure element ( 3 ), at least one leaf feather-like spring arm ( 2.2 ) and at least one wing-like limiter arm ( 2.3 ), wherein the spring arm ( 2.2 ) for biasing the closure element ( 3 ) is supported relative to the battery housing (B) and the limiting arm ( 2.3 ) is arranged such that this with the battery housing (B) has a stop for limiting an opening path of the closure element ( 3 ) with respect to the battery case (B). Battery according to claim 1, characterized in that the spring element ( 2 ) two oppositely disposed spring arms ( 2.2 ) and two oppositely arranged stop arms ( 2.3 ) having. Battery according to claim 1 or 2, characterized in that the closure element ( 3 ) is substantially plate-shaped and a central retaining lug ( 3.1 ), which with the spring element ( 2 ) connected is. Battery according to one of the preceding claims, characterized in that the closure element ( 3 ) in a peripheral edge region ( 3.2 ) a seal ( 4 ) for sealing the closure element ( 3 ) relative to the battery case (B). Battery according to one of the preceding claims, characterized in that the closure element ( 3 ) at least one opening ( 3.3 ), which by means of a closure means ( 5 ), which is formed by a gas-permeable and liquid-tight material or composite material. Battery according to claim 4, characterized in that the closure means ( 5 ) with the closure element ( 3 ) is positively, positively and / or materially connected. Battery according to claim 4 or 5, characterized in that the closure means ( 5 ) with the closure element ( 3 ) by means of the spring element ( 2 ) is pressed non-positively. Battery according to one of claims 4 to 6, characterized in that the material and / or the composite material of the closure means ( 5 ) is hydrophobic and / or oleophobic. Battery according to one of claims 4 to 7, characterized in that the material and / or the composite material of the closure means ( 5 ) comprises a plastic material, in particular a polyethylene, a polyethersulfone and / or a polytetrafluoroethylene. Battery according to one of claims 4 to 8, characterized in that the closure means ( 5 ) is designed as a membrane.

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