Battery Valve

Abstract

A valve for a battery, adapted to release air in the event of overpressure occurring in the battery due to heating of the battery cells, comprises an outer body (2) and a plunger (3) which moves inside, pushed by the pressure of the battery. The valve has two opening positions depending on the level of pressure generated, by coupling to the plunger at least: a first O-ring (5) which closes the air passage when there is no pressure and opens the air passage when the plunger (3) moves to the first position with a given degree of pressure, a second O-ring (6) which prevents the air from being discharged directly to the outside when there is only the first degree of pressure and allows the plunger (3) to open to the second position when the pressure degree is exceeded, and a vent element (4) which allows the passage of air but not water in the passage.

Description

[Technical field]

[0001] Objective of the invention The present invention relates to a valve for a battery, which contributes to the function for which it is designed, as described in the heading of this specification, and whose advantages and features are disclosed in detail hereinafter.

[0002] The object of the invention is a valve for an electric battery intended to release the eventual overpressure charge that occurs inside it due to the heat of the cells, characterized in that it is designed with a structure that provides a two-stage opening depending on the level of pressure that occurs.

[0003] Field of application of the present invention The field of application of the invention lies within the field of industry involved in the production of batteries, but also including the production of pressure valves. [Background technology]

[0004] As is known, electric batteries (particularly those constituted by a number of cells assembled in an airtight casing) can exhibit overpressure caused by an excessive increase in heat generated by the cells, which, in the absence of a safety valve, can eventually give rise to a risk of explosion or at least a risk of deterioration and failure of the battery.

[0005] The object of the present invention is therefore to develop a valve for avoiding situations and relieving overpressure, which valve furthermore makes it possible to adjust the relief in relation to the level of pressure that occurs.

[0006] On the other hand, with reference to the current state of the art, although the existence of battery safety valves is known, the applicant is not aware of any having the same or similar technical and structural features as those claimed in this specification. Summary of the Invention

[0007] The battery valve proposed by the present invention constitutes an improved alternative to the already known one and is suitable as a means for solving the above-mentioned objects, the characteristic details which enable and distinguish it are conveniently set out in the final claims attached to the description.

[0008] In particular, what the invention proposes is, as mentioned above, a valve for an electric battery, in particular one composed of several cells housed in an airtight casing, intended to act as a safety element for the release of eventual overpressure loads generated inside due to the heat of the cells, and presents the advantageous feature of being designed with a structure providing two opening levels adapted to act depending on the level of pressure generated, so that from a given pressure level the valve opens in a first position and from a second pressure level the valve opens in a second position, so that the opening of the valve is not always the same but is adapted to the need for pressure release depending on the degree of pressure that needs to be relieved.

[0009] Thus, more specifically, the valve object of the present invention conventionally comprises a cylindrical outer body within which a plunger is arranged to move between closed and open positions to close and open an air passage between opposite sides of the outer body, the proximal side remaining in contact with the inside of the battery casing and the opposite or distal side remaining open to the outside.

[0010] The valve of the present invention differs from the above-mentioned known configurations essentially in that the plunger is formed by a stem and a hollow head, the stem being inserted into a central hole in the wall separating the proximal side of the outer body from the distal side of the body in which the head remains, the valve having a first O-ring assembled in the joining area between the stem and the plunger head and a second O-ring assembled at the distal end of the plunger head, the latter having assembled therearound a venting element or a Gore® vented valve closing the open end of the plunger head, and further having a number of peripheral through holes.

[0011] Thus, when the valve is in the rest position, in the absence of excess pressure, the first plunger fits and seals into the hole in the wall through which the stem is inserted, closing off the passage of air from one side of the outer body of the valve to the other.

[0012] When a predetermined pressure value is exceeded within the battery, the pressure pushes the plunger, causing the stem and the first O-ring to move from the fitting of the hole towards the distal side of the outer body, and air flows towards the distal side of the outer body, where a first chamber is formed by adjusting the second O-ring with the inner wall of the outer body, so that air that cannot be directly exhausted to the outside is supplied into the head of the plunger through the peripheral through-holes provided in the head of the plunger and exhausted to the outside from the inside of the head defining the second or intermediate chamber through a ventilation element that prevents the ingress of water but allows the escape of air. The ventilation element is preferably a Gore® vent valve.

[0013] It should be noted that this Gore® vented ventilation element is made from a material that allows air to escape but prevents water from getting in, as water in a battery can be very dangerous. However, this type of material does not prevent moisture from getting in.

[0014] This configuration is interesting because if the first pressure level is not exceeded, the ventilation element is not activated, making it impossible for air to flow between the inside and outside of the battery and also impossible for external moisture to penetrate into the inside of the battery. In other words, this configuration prevents water from entering but limits the opening time of the ventilation element, which allows air to escape.

[0015] When a second degree of pressure is exceeded inside the battery, the plunger moves further towards the distal side of the outer body, so that the second O-ring reaches an area with lateral holes close to the distal end of the outer body, which allows the air to be vented from the first chamber directly to the outside through the lateral holes, in addition to being able to be vented from the intermediate chamber defined by the head of the plunger through the above-mentioned venting element, so that the pressure relief is greater and it is possible to absorb a higher degree of pressure inside the battery. This higher venting is interesting to avoid the explosion of the battery caused by overpressure due to thermal runaway, when the temperature of the cell rises too high and cannot be lowered, and the cell begins to burn on itself. This rapid temperature rise causes a rapid pressure rise that can cause the battery to become exposed if the generated overpressure is not quickly released.

[0016] Finally, it should be noted that the valve is preferably designed so that: - If the pressure is below 0.1 bar, the plunger does not move and the air passage remains closed. - Between 0.1 bar and 0.7 bar pressure, the plunger will only move to the initial open position. - When the pressure exceeds 0.7 bar, the plunger moves to the second open position. [Brief description of the drawings]

[0017] To complement the description given and to aid in the best understanding of the features of the invention, the present specification is accompanied by, as an integral part thereof, drawings, which are given by way of illustration and not by way of limitation, and in which:

[0018] [Figure 1] 1 shows a schematic cross-sectional view of an example of an embodiment of a valve for a battery object of the present invention, which is represented in a closed or rest position and in which the constituent parts and elements are visible. [Diagram 2]2 shows a diagram of a valve of the invention similar to that shown in FIG. 1, in this case shown in a first open position which is reached when a predetermined pressure value is exceeded. [Diagram 3] 1 shows a cross-sectional view of a valve similar to the previous figure, in this case shown in a second open position reached when a second degree of pressure is exceeded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] With reference to the figures above and in accordance with the numerals employed, non-limiting examples of embodiments of the battery valve of the present invention comprising what is described in detail hereinafter can be seen therein.

[0020] Thus, as can be seen in the above figure, the valve (1) of the present invention applicable in its embodiment in the casing (not shown) of a cell battery as a safety measure to relieve the eventual overpressure caused by the heat of the cells in the casing, - a cylindrical outer body (2) comprising: - a housing (21) opening on the proximal side (2a) towards the inside of the battery casing, - an outer chamber (22) open to the outside at its distal side (2b) and having a continuous lateral hole (23) at the end of the outer chamber (22), - a cylindrical outer body (2) having between its two sides a partition (24) with a central hole (25); - an internal plunger (3) that slides between the two sides of the outer body (2), said internal plunger (3) being - a stem (31) that is inserted into the central hole (25) of the bulkhead (24) and remains oriented towards the housing (21) on the proximal side (2a); - a head (32) having a larger diameter than the stem (31) and remaining disposed in the outer chamber (22) on the distal side (2b), the head (32) being hollow inside and defining a second or intermediate chamber (33) in which there is a continuous peripheral through hole (34); - an internal plunger (3) provided with a ventilation element (4), in particular a Gore® vented valve, which closes the end of the head (32) of the plunger (3) and allows the passage of air but not moisture; - a first O-ring (5) incorporated in the plunger (3) in the joining area between the stem (31) and the head (32), adapted to fit and seal in the central hole (25) of the wall (24) through which the stem (31) of the plunger (3) is inserted; - a second O-ring (6) fitted around the head (32) of the stem (3) and adapted to fit the inner wall of the chamber (22) of the outer body (2); Equipped with.

[0021] Taking all this into account, the operation of the valve is as follows: - When there is no pressure in the battery, preferably less than 0.1 bar, the plunger (3) is in the closed position (figure 1) and therefore the first O-ring (5) seals the central hole (25) through which the stem (31) is inserted, preventing the passage of air from the battery to the outside.

[0022] - when there is a certain degree of pressure in the battery, preferably between 0.1 and 0.7 bar, the pressure pushes the plunger (3) towards the distal side (2b) of the outer body (2), which separates the first O-ring (5) from the central bore (25) in which it fits, allowing the passage of air from the housing (21) on the proximal side (2a) towards the outer chamber (22) through the central bore (25), which remains retained by the adjustment of the second O-ring (6) in the wall of the outer chamber, penetrating into the intermediate chamber (33) through the through-hole (34) of the intermediate chamber (33) defined by the head (32) of the plunger (3) and then venting to the outside through the ventilation element (4), as shown in FIG. 2.

[0023] - and when the pressure in the battery becomes higher, preferably above 0.7 bar, the plunger (3) moves even further towards the distal side (2b) of the outer body (2) until the second O-ring (6) remains aligned with the side hole (23) of the outer chamber (22), allowing air to be vented directly to the outside through the side hole (23) in addition to continuing to be vented through the ventilation element (4), as shown in FIG. 3.

[0024] Preferably, to ensure the fixation of the vent element (4), a second O-ring (6) is fitted into a peripheral notch of the element which fits into the end of the head (32) of the plunger (3), thereby ensuring at the same time the sealing effect of this second O-ring (8) with the inner wall of the outer chamber (22).

[0025] Preferably, the central hole (25) of the partition (24) of the outer body (2) has a conical shape opening towards the outer chamber (22) in order to provide space for adjusting the first O-ring (5) therein.

[0026] Preferably, the housing (21) on the proximal side (2a) of the outer body (2) is provided with a spring (7) to allow adjustment of the assembly to a connector (not shown) located in the casing of the battery.

[0027] Similarly, the end of the stem (31) of the plunger (3), which remains oriented towards the battery, incorporates a stop (8) that prevents the stem (31) from passing through the central bore (25) beyond a predetermined point and the plunger from moving out of position.

[0028] On the other hand, in a preferred embodiment, the valve further comprises a third O-ring (9) located externally relative to the outer body (2), near the peripheral thickening (26) of the outer body (2), provided for coupling to a battery connector.

[0029] In summary, therefore, the subject of the present invention is a valve (1) applicable to release air in the event of overpressure occurring in a battery due to heating of the cells of the battery, and is distinguished in that it is composed of an outer body (2) and a plunger (3) which is pushed and moves inside it by the pressure of the battery, and which presents two opening positions depending on the level of pressure occurring, and this valve (1) has at least: - a first O-ring (5) that closes the air passage in the absence of pressure and opens the air passage when the plunger (3) moves to the first position with a predetermined degree of pressure; - a second O-ring (6) which prevents direct air escape to the outside when only the first pressure level is present and allows the plunger (3) to open to the second position when the pressure level is exceeded; - a ventilation element (4) which, in both open positions, allows the passage of air but not moisture; is coupled to the plunger (3).

[0030] The nature of the present invention and its embodiments have been fully disclosed and those skilled in the art can appreciate its extensibility and advantages arising therefrom, so that no further expansion of the description is believed necessary.

Claims

1. A battery valve applicable to release air when overpressure occurs in a battery due to heating of a cell of the battery, and comprising an outer body (2) and a plunger (3) that is pushed by the pressure of the battery and moves inside the outer body (2), the valve comprising at least: a first O-ring (5) that closes the air passage in the absence of pressure and opens said air passage when said plunger (3) is moved to a first position by a predetermined degree of pressure; a second O-ring (6) that prevents the air from escaping directly to the outside when there is only a first degree of pressure and allows the plunger (3) to open to a second position when this degree of pressure is exceeded; a ventilation element (4) that allows the passage of said air through the passages but does not allow the passage of moisture; to said plunger (3), so that it has two opening positions depending on the level of pressure generated, This battery valve is characterized in that the vent element (4) is activated only when the first pressure level is exceeded, and in this situation allows the overpressure to be released through the vent element (4), thus preventing the ingress of moisture through the vent element (4) when the first pressure level is not exceeded, and thereby allowing the overpressure to be released quickly when a second pressure level is exceeded, since there is direct communication between the inside of the battery and the outside of the battery, without passing through the vent element (4).

2. The battery valve a cylindrical outer body (2), a housing (21) that opens on its proximal side (2a) into the inside of the casing of the battery; an outer chamber (22) open to the outside at its distal side (2b) and having a continuous lateral hole (23) at the end of said outer chamber (22); a cylindrical outer body (2) with a partition (24) between its two sides, having a central hole (25); an internal plunger (3) that slides between the two sides of said outer body (2), a stem (31) inserted into the central hole (25) of the septum (24) and remaining oriented towards the housing (21) on the proximal side (2a); a head (32) having a diameter greater than that of the stem (31) and remaining disposed in the outer chamber (22) on the distal side (2b), the head (32) defining a second or intermediate chamber (33) hollow therein and having a continuous peripheral through-hole (34); an internal plunger (3) comprising a ventilation element (4) that closes the end of the head (32) of said plunger (3) and allows the passage of said air but not water through the passages; a first O-ring (5) incorporated into the plunger (3) in the joint area between the stem (31) and the head (32), adapted to fit and seal the central hole (25) of the wall (24) into which the stem (31) of the plunger (3) is inserted; and a second O-ring (6) fitted around the head (32) of said stem (3) and adapted to fit the inner wall of the chamber (22) of said outer body (2); This means: - when there is no pressure in the battery, the plunger (3) is in a closed position and the first O-ring (5) seals the central hole (25) through which the stem (31) is inserted, preventing the passage of air from the battery to the outside; - when there is a predetermined degree of pressure in the battery, said pressure pushes the plunger (3) towards the distal side (2b) of the outer body (2), separating the first O-ring (5) from the central hole (25) and allowing the passage of the air towards the outer chamber (22) and into the passage, the air remaining retained by the second O-ring (6), penetrating into the intermediate chamber (33) through the through-holes (34) of the intermediate chamber (33) and venting to the outside through the ventilation element (4); 2. A battery valve according to claim 1, characterized in that, when the pressure inside the battery becomes higher, the plunger (3) moves even further towards the second O-ring (6), which remains aligned with the side hole (23) of the outer chamber (22), allowing the air to be discharged directly to the outside in addition to being discharged through the ventilation element (4).

3. 3. A battery valve according to claim 2, characterized in that the second O-ring (6) is fitted into a peripheral notch of the vent element (4) that fits into the end of the head (32) of the plunger (3).

4. 3. The battery valve according to claim 2, characterized in that the central hole (25) of the partition (24) of the outer body (2) has a conical shape opening towards the outer chamber (22) to provide space for adjustment of the first O-ring (5) of the outer chamber (22).

5. 3. A battery valve according to claim 2, characterized in that in the housing (21) on the proximal side (2a) of the outer body (2) a spring (7) is provided to enable adjustment of the assembly to a connector provided in the casing of the battery.

6. 3. A battery valve according to claim 2, characterized in that at the end of the stem (31) of the plunger (3) there is a stop (8) which prevents the stem (31) from passing through the central hole (25) beyond a certain point.

7. 2. The battery valve according to claim 1, wherein the vent element (4) is a Gore® vented valve.

8. 8. A battery valve according to claim 1, characterized in that at a pressure below 0.1 bar the plunger (3) does not move and the air passage remains closed, at a pressure between 0.1 bar and 0.7 bar the plunger (3) moves to a first open position, and at a pressure above 0.7 bar the plunger moves to a second open position.

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