WO2012091669A1

WO2012091669A1 - Plug for battery and battery

Info

Publication number: WO2012091669A1
Application number: PCT/SE2011/051600
Authority: WO
Inventors: Karin Carlsson; Ola Riseby
Original assignee: EFFPOWER AB
Current assignee: EFFPOWER AB
Priority date: 2010-12-29
Filing date: 2011-12-28
Publication date: 2012-07-05
Anticipated expiration: 2013-06-29
Also published as: SE1001231A1; SE535483C2

Abstract

A plug (1) for a battery having engagement elements (4) for the co-operation with corresponding elements in a hole (22) in a battery (21), wherein the plug for the battery includes a valve chamber (10) with a valve seat (11), against which a valve surface (24) of a valve body (12) is arranged to be in preloaded contact, and wherein in the valve chamber (10) there is arranged a pressing portion (13) for pressing against a press surface (14') on the valve body (12) for achieving said preloaded contact. The pressing portion (13) and the valve body (12) comprise co-operating means for guiding the valve body (12) and for limiting sideways movement of the press surface (14') as seen from an axis (16) extending through the valve body (12). The invention also relates to a method and a battery being provided with at least one such plug.

Description

PLUG FOR BATTERY AND BATTERY

FIELD OF THE INVENTION

The invention concerns a plug for a battery having engagement elements for the co-operation with corresponding elements in a hole in a battery, wherein the plug for the battery includes a valve chamber with a valve seat, against which a valve surface of a valve body is arranged to be in preloaded contact, wherein in the valve chamber there is arranged a pressing portion for pressing against a press surface on the valve body for achieving said preloaded

contact, and whereby the valve body at least partly is of a flexible material . The invention also concerns a method and a battery including at least one such plug for a battery.

BACKGROUND OF THE INVENTION

In a rechargeable battery having sulphuric acid included in the electrolyte and with lead or a corresponding metal being included in the electrodes, gases are emitted during the chemical reaction, in particular during charging. Such gases are, according to the background art, allowed to depart from the battery enclosure in a more or less controlled manner, wherein different valve systems have been used.

A plug for a battery of the kind defined above is previously known from US 6,528,202 Bl, wherein a valve body of a flexible, elastic material is preloaded inside valve

housing .

In the battery plug according to US 6,844,104 B2 a valve body having a ring-shaped sealing lip lies against a valve seat which is also ring-shaped. Pressure formed inside the battery above a certain limit forces the valve body to allow exit of gas against the action of a preload arrangement inside the plug.

I RECORD COPY-TRANSLATION

L (Rule 12,4) AIM AND MOST IMPORTANT FEATURES OF THE INVENTION

It is an aim of the present invention to provide a further developed plug for a battery which has increased ability to withstand higher battery pressure and has enhanced functionality.

This aim is obtained in a plug for a battery according to the above by the pressing portion and the valve body

comprising co-operating means for guiding the valve body and for limiting sideways movement of the press surface as seen from an axis extending through the valve body. In practice this will result in that sideways movement of the press surface will be prevented whereby is achieved a secure guiding of the valve body since it is made possible to position the guiding means at a great distance from the valve surface - the valve seat. Hereby it is achieved that the valve body can be dimensioned for essentially higher pressure and still provides secure sealing functionality at intended pressure with

maintained positioning of the valve body in respect of the valve seat. This is a great advantages compared to the

background art, with only relatively low battery pressures, and it further is a risk of tilting of the valve body

resulting in risk of leakage and altogether uncontrolled maintained battery pressure. It can be mentioned that the invention is preferred also in respect of lower pressures because of enhanced tightness in close position of the valve body as a result of the inventive guiding of the valve body. Through the invention is also achieved that opening pressure and closing pressure of the valve will become closer to each other than what is the case for plugs according to the

background art.

It is preferred that said co-operating means are a guiding recess and a guiding protrusion being associated with a respective one of the press surface and the pressing portion. This construction gives the possibility of simple and cost-effective production and still reliable operation. In particular it is preferred that the guiding recess is arranged on a lid of the plug whereas the guiding protrusion is

arranged on the valve body. Hereby the guiding recess is preferably comprised of a cavity and the guiding protrusion preferably of a rounded end portion. It is, however, within the scope of the invention to construct the end portion

differently, for example as a more flattened end portion. The cavity of the guiding recess preferably exhibits such a width crosswise to a pressing directions D that it essentially corresponds to the width of the end portion of the guiding protrusion in its deformed state with preloaded valve body.

Bu choice of dimensions and materials with different properties, a desired pressure level can be determined, wherein the valve body will allow gas exit.

Said axis is preferably a symmetry axis of the valve body which suitably is at least partially rotationally symmetrical.

In particular the guiding protrusion and a portion of the valve body which co-operates with the valve seat (named valve surface) are of a flexible material, whereby is to be

understood that the preload is obtained through elastic properties of the flexible material which gives the intended force during preload when it is pressed together.

It is, however, preferred that the valve body as a whole is produced unitarily from such material having such

properties such as suitable adjusted flexibility and

elasticity as well as resistance against the chemicals that are present in battery. It is preferred that the flexible material at least partly being included in the valve body are from the group: a rubber material, a plastic material.

Preferably the valve body is pre- fatigued before it is mounted inside the plug. This means that the valve body is pressed together a number of times before mounting and/or has been subjected to other process steps, such as having been heat-treated to a certain temperature, in order to avoid subsequent changes of its ability to resist and open at the correct pressure.

Suitably the pressing portion is arranged on a lid of the plug, said lid together with a main portion enclosing the valve chamber. The lid is suitably positioned with pretention in the main portion in order to ensure secure fastening, which is accentuated by a lid and the main portion comprising mutual engagement means for engagement with each other.

Preferably a flame damper is arranged in the area of the pressing portion suitably being ring-shaped and surrounding the pressing portion.

The valve chamber includes in a lower portion suitably an inlet chamber with at least one inlet channel for gas inlet from the battery and in an upper portion an outlet chamber with at least one outlet channel for gas outlet from the plug.

Preferably the valve body has a ring-shaped sealing lip for lying against the valve seat which is also ring-shaped.

It is preferred that the valve body exhibits a protruding portion which is adapted to be arranged inside the ring-shaped valve seat .

Corresponding advantages are obtained in respect of a battery with a container including a plurality of electrodes and electrolyte, wherein the battery includes at least one plug for a battery according to the above.

The invention also relates to a method for venting a battery, the method being distinguish in that the movement sideways of the press surface, as seen from an axes extending through the valve body, is limited by the pressing portion and the press surface having co-operating means for guiding the valve body. Features corresponding to the above mentioned preferred device features can optionally be present in respect of the inventive method.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described by way of embodiments and with reference to the annexed drawings, wherein:

Fig. la illustrates a plug for a battery according to the invention in a side view,

Fig. lb illustrates the plug for a battery according to the invention in a perspective view,

Fig. 2 illustrates an axial section through the plug for a battery in Fig. la,

Fig. 2a shows a detail of the axial section of the plug for a battery in Fig. 2, and

Fig. 3 shows diagrammatically a battery including a plurality of plugs for a battery according to the invention.

DESCRIPTION OF EMBODYMENTS

In Fig. la and b are shown a plug for a battery 1, which includes a cup-shaped main portion 2 and a lid 3, together enclosing a valve chamber. The main portion 2 is essentially rotationally symmetrical and exhibits engagement elements for the co-operation with corresponding elements in a battery in the form of thread 4. In an upper region of the main portion 2 is arranged a flange 5 which co-operates with a (not shown) O- ring, which when the battery plug 1 is screwed into a hole in a battery provides an outer seal relative to a battery

surface. 7 indicates a key grip for the co-operation with a wrench for screwing the battery plug 1 into the battery.

In a lower region of the main portion 2 is arranged inlet channels 8 (one shown) into said valve chamber for gas being formed during operation of the battery. The lid 3 exhibits usual (not shown) means arranged to contact an upper part of said valve chamber with the surroundings (the atmosphere) .

In Fig. 2 the battery plug 1 is shown in an axial section and with some of the details seen in section. Said valve chamber is indicated with 10, and inside it there is placed a valve seat 11, which is ring-shaped, and which co-operates with a likewise ring-shaped sealing lip 24, being arranged on a valve body 12. The sealing lip 24 is arranged axially

directed on the valve body 12 and the valve seat 11 is

comprised of a surface which is directed axially in an

opposite direction, said surface thus extending radially in a plane at a right angle to a rotational symmetry axis 16 of the valve body and the plug and thus of the valve seat.

Further, in the valve chamber 11 and in particular on the lid 3, there is arranged a pressing portion 13 which is arranged centrally in the valve chamber and which co-operates with a guiding protrusion 14 which is positioned centrally on the valve body. The guiding protrusion 14 has in particular a press surface 14' in the form of a rounded end portion on an upper central part of the valve body 12.

The pressing portion 13 has on a free end portion a guiding recess 15, being directed towards the valve body 12, in the form of a cavity which receives said rounded end portion of the guiding protrusion 14.

In use of the battery plug 1 according to the invention, the lid 3 will provide a certain pretension force against the valve body 12 in order to maintain the valve function of the battery plug up to a certain predetermined pressure level inside the battery. This is achieved according to the

invention through dimensioning of the lid 3 and in particular that the length of the pressing portion 13 is adapted in relation to the position and dimensions of the valve body 12, and in particular the position of its guiding protrusion 14, together with the elastic properties of the flexible material of the valve body, so that the lid 3 in its inserted position inside the main portion 2 provides the required pretention effect in order to resist pressures up to a certain pressure level .

In an engagement position of the lid 3 in the main portion 2, mutual engagement means 26, 27 arranged

peripherally on the lid and inside in a lid seat in the main portion 2 are in engagement with each other. In the shown embodiment, the lid is provided with a radially outwardly directed surrounding ridge 26, which engages in a

corresponding surrounding groove being inwardly directed in the main portion 2.

In particular it is intended that a lid 3 and its pressing portion 13 in a pressing direction D presses together the guiding protrusion 14 of the valve body 12. This is illustrated in the detailed representation in Fig. 2a. From this figure it is clear that the guiding protrusion 14 has been deformed such that the press surface 14' is lying

essentially against the entire surface of the guiding recess 15 and essentially over the entire width W of the cavity of the guiding recess 15. Further is included application of the press surface 14' against an inwardly, towards a centre of the guiding recess, directed surrounding flange 15' . The cavity of the guiding recess 15 is thereby brought to control the guiding protrusion 14 sideways and limit and in operation prevent its movement sideways at seen in respect of the symmetry axis 16 of the plug and of the valve body 12. Hereby it is achieved that the valve body will lie aligned inside the valve chamber 10 and will not tend to tilt in any direction.

Hereby is ensured secure and stabilised valve function of the sealing lip 24 against the valve seat 11. Fig. 2 thus shows the guiding protrusion 14 in un- deformed state, which explains that this figure does not give a true picture of the co-operation between the guiding

protrusion 14 and the guiding recess 15. A true state of the guiding protrusion 14 in its co-operation with guiding recess 15 is shown in Fig. 2a, wherein the press surface 14' is flattened and spread out such that it will lie against the entire guiding recess 15 including the surrounding flange 15' of the cavity.

The cavity of the guiding recess 15 can be formed in different ways, for example as is shown in Fig. 2 (completed with interrupted lines) with plane lower surface and conically extended flange 15' . It is also possible for example to shape the cavity more rounded as seen in a section.

Inside the valve chamber 10 there is also arranged a ring-shaped flame damper 17, which in the shown embodiment is positioned in a suitable place, namely surrounding the

pressing portion 13, which in this area has a circular

cylindrical outer surface. The flame damper 17 is positioned inserted in a flame damper seat arranged in the upper part of the main portion 2.

At its lower part, the valve body 12 is provided with a protruding portion 25, which is arranged to extend inside said ring-shaped valve seat 11 for guiding purposes, such that the sideward movements of the valve body 12 are limited also in this region.

In use of the battery plug 1 according to the invention, the valve body 12 will resist a gas pressure inside a battery, said gas pressure being transmitted over the inlet channel 8 to an inlet chamber 18 inside the valve chamber 10. Pressure above a set valve pressure of the battery plug 1 leads to raising of the valve body 12 and in particular its sealing lip 24 from the valve seat 11 and flow of gas through there to the area 19 above said valve seat 11. This gas will thereupon flow through the flame damper 17 being positioned around the

pressing portion 13, said flame damper being pervious for gas, and to an outlet chamber 20 with (not shown) outlet channel means in the lid 3.

Through the construction according to the invention it is allowed that valve bodies 12 can be constructed which have relatively large height from its sealing lip 24 and still provides a secure function also at relatively high pressures. Higher pressures than in respect of known corresponding

battery plugs can among others things therefore be handled with a battery plugs according to the invention.

The valve body 12 is preferably produced from one

flexible material in its entirety but this is also possible to construct the valve body 12 with only the sealing lip 24 and the guiding protrusion 14 of a flexible material, whereas the remaining portions of the valve body 12 can be made from a relatively rigid material .

The pressing portion 13 is shown with a recess 28 at the outside of the lid which has to do with manufacture of the lid and in particular that it is desired to construct the lid with as equal material thickness as possible in order to avoid shape changes after forming. Also the shallow recess 29 at the outside of the lid has this background related to the

importance of the lid to be able to sit firmly without play in snapped-in position.

It can be mentioned that such unwanted form changes could result in corresponding unwanted variations in plug pressure level .

Fig. 3 shows diagrammatically a battery 21 with an outer container which includes a number of electrodes, electrolyte etc. (not shown) . The battery 21 exhibits a number of holes 22 as usual for the positioning of battery plugs 1 according to W

10 the invention in the respective holes 22. 23 indicates battery poles for connection to a load.

The invention can be modified within the scope of the annexed claims and the means of the battery plug defining the valve chamber could be arranged differently. It can be

mentioned that the pressing portion and the guiding protrusion can be formed otherwise such that guiding of the valve body 12 is achieved by most upwardly on the valve body there being arranged a guiding recess whereas that on the co-operating portion of the lid 3 or on any other portion of the housing of the plug 1 there is arranged a guiding protrusion with a press surface corresponding to what is shown on Fig. 2 and being indicated with 14' . The construction that is described above, wherein most upwardly on the valve body 2 there is arranged a guiding protrusion with a press surface whereas on the cooperating part of the lid 3 there is arranged a pressing portion 13 with a guiding recess is however preferred.

It is preferred that the components of the battery plug are made from a synthetic material such as for each element any suitable one of different plastic materials (except for the flame damper) and that the valve body 12 is a homogeneous body of a suitable flexible plastic material having elastic properties according to the above.

Claims

C L A I M S

1. Plug (1) for a battery having engagement elements (4) for the co-operation with corresponding elements in a hole (22) in a battery (21) , wherein the plug for the battery includes a valve chamber (10) with a valve seat (11) , against which a valve surface (24) of a valve body (12) is arranged to be in preloaded contact, wherein in the valve chamber (10) there is arranged a pressing portion (13) for pressing against a press surface (14') on the valve body (12) for achieving said preloaded contact, and whereby the valve body (12) at least partly is of a flexible material, c h a r a c t e r i z e d in

- that the pressing portion (13) and the valve body (12) comprise co-operating means for guiding the valve body (12) and for limiting sideways movement of the press surface (14') as seen from an axis (16) extending through the valve body (12) .

2. Plug according to claim 1, c h a r a c t e r i z e d in that said co-operating means are a guiding recess (15) and a guiding protrusion (14) respectively.

3. Plug according to claim 2, c h a r a c t e r i z e d in that the guiding recess (15) is comprised of a cavity and that the guiding protrusion (14) exhibits a rounded end portion.

4. Plug according to claim 3, c h a r a c t e r i z e d in that the cavity of the guiding recess (15) exhibits such width (W) crosswise to a pressing direction (D) that it essentially corresponds to the width of the end portion of the guiding protrusion (14) in deformed state with preloaded valve body

5. Plug according to any one of the previous claims,

c h a r a c t e r i z e d in that said axis (16) is a symmetry axis of the valve body (12) .

6. Plug according to any one of the previous claims,

c h a r a c t e r i z e d in that said flexible material at least partly being including in the valve body (12) is one from the group: a rubber material, a plastic material.

7. Plug according to claim 6, c h a r a c t e r i z e d in that the valve body (12) is pre- fatigued before it has been mounted inside the plug.

8. Plug according to anyone of the previous claims,

c h a r a c t e r i z e d in that the pressing portion (13) is arranged on a lid (3) of the plug, said lid (3) together with a main portion (2) surrounding the valve chamber (10) .

9. Plug according to claim 8, c h a r a c t e r i z e d in that the lid (3) is positioned with pretention in the main portion and that these elements include mutual engagement means .

10. Plug according to any one of the previous claims,

c h a r a c t e r i z e d in that a flame damper (7) is arranged in the area of the pressing portion (13) .

11. Plug according to claim 10, c h a r a c t e r i z e d in that the flame damper (7) is ring-shaped and arranged

surrounding the pressing portion (13).

12. Plug according to any one of the previous claims, c h a r a c t e r i z e d in that the valve chamber (10) in a lower portion includes an inlet chamber (18) having at least one inlet channel (8) for gas inlet from the battery and, in an upper portion, an outlet chamber (20) with at least one outlet channel (9) for gas outlet from the plug (1) .

13. Plug according to any one of the previous claims,

c h a r a c t e r i z e d in that the valve body (12) exhibits a ring-shaped sealing lid (24) for contacting against the valve seat (11) which is also ring-shaped.

14. Plug according to claim 13, c h a r a c t e r i z e d in that the valve body (12) exhibits a protruding portion (25) which is adapted to be arranged inside the ring-shaped valve (11) .

15. Method for venting a battery, which exhibits at least one plug for a battery (1) including a valve chamber (10) with a valve seat (11), against which a valve surface (24) of a valve body (12) is arranged to be in preloaded contact, and wherein inside the valve chamber (10) there is arranged a pressing portion (13) for pressing against a press surface (14') being arranged on the valve body (12) in order to obtain said preloaded contact and wherein the valve body (12) at least partly is of a flexible material,

c h a r a c t e r i z e d in

- that sideways movement of the press surface (14') as seen from an axis (16) extending through the valve body (12) is limited by the pressing portion (13) and the press surface (14') exhibiting co-operating means for guiding the valve body (12) .

16. Battery (21) with a container including a plurality of electrodes and electrolyte, wherein the battery includes at least one plug (1) for a battery according to any one of the claims 1 - 14.