PRESSURE BALANCING DEVICE

Technical Field

The present invention relates to a pressure balancing device used for balancing the internal pressure of the housing of an electrochemical device and the external environment pressure.

In particular, the invention relates to a pressure balancing device used in electrical vehicle batteries to balance the pressure difference between the battery housing and the external environment as a result of the pressure increase in the battery housing and to prevent explosion that may occur in the battery.

State of the Art

The power to the engines of electric or hybrid vehicles is provided by electrochemical devices such as batteries, etc. Batteries produce gas during operation or generate temperature increases depending on the operation. In both cases, it causes an increase in pressure in the closed battery volume. Due to the increase in pressure, the operating efficiency of the battery decreases, and/or explosions may occur.

Different types of pressure balancing devices are currently used to prevent pressure increase in the battery housing. Pressure balancing devices balance the pressure difference between the internal pressure of the battery housing and the external environment pressure.

The document US2006275654A1 discloses a ventilation valve for use in batteries. The ventilation valve consists of a cap and a body. The ventilation valve is mounted on the fill tube of the battery by means of the body. The cap located at the upper end of the body closes the fill tube opening. The cylindrical sidewall of the cap extends downwards and surrounds the fill tube. Thus, the cylindrical sidewall acts as a resilient seal around the fill tube. When the internal pressure of the battery increases, the cylindrical sidewall flexes outward with the pressure of the fluid pressure coming from the inside, allowing the pressure to be released. When the external environment pressure and the internal pressure of the battery housing are balanced, the cylindrical sidewall recloses around the fill tube. Pressure balancing elements made of flexible material become useless because of time depending deformation. Moreover, the operation pressure ranges of the pressure balancing elements are not precise because of the flexibility of the material.

The document WO2020241466A1 discloses a pressure relief valve connected to an opening of the battery. The pressure relief valve comprises a housing with a discharge hole that communicates with the external environment and a valve mechanism to open and close the said discharge hole. There is a cover on the housing, and the discharge hole located between the housing and the cover performs the gas release process. The valve mechanism comprises a valve element that closes the discharge hole and a spring that keeps the valve element in the closing position.

The high component quantity in the pressure balancing elements makes it difficult to assemble the components during production and increases production costs.

In present art, the geometry of the lower surface of the cover/cap in the pressure balancing devices makes it difficult for the gas flow to come out.

As a result, due to above described disadvantages and inadequacy of existing solutions, it has been necessary to make development in the related art.

Purpose of the Invention

The invention has been developed with inspiration from existing situation and purposes to eliminate the above-mentioned disadvantages.

The main purpose of the invention is to reduce the number of factors affecting the opening pressure in the pressure balancing device. In the pressure balancing device of the invention, only the spring constant determines the opening pressure of the cover. Thus, changes in the opening pressure of the pressure balancing device, which are produced in different periods or depending on the use in time, are prevented.

Another purpose of the invention is to provide a pressure balancing device capable of performing pressure equalization even with small-scale pressure changes. The pressure balancing device is automatically opened and closed in small-scale pressure increases by means of the spring system used in the pressure balancing device of the invention.

Another purpose of the invention is to develop a cover geometry that allows the amount of fluid passing per unit time to increase when a difference between the internal pressure of the battery housing and the external pressure occurs. In the present invention, the geometry of the part of the cap facing the battery is in a concave form and increases the amount of fluid passing through.

Another purpose of the invention is to enable the pressure balancing device to be mounted on the battery without the need for any mounting apparatus. The pressure balancing device is mounted on the battery thanks to the locking tabs located on the body.

Another purpose of the invention is to provide sealing protection in different IP ratings by means of a first sealing element positioned between the body and the cap. The first sealing element has the form “V”. In this way, the first sealing element provides sealing protection in the IP65, IP66, IP67, IP68 and IP69K ratings. The pointed end of the “V” shape of the first sealing element is positioned to face the flow channel. This placement of the first sealing element ensures an increase in the amount of fluid discharged per unit time.

Another purpose of the invention is to provide a pressure balancing device with a sealing element that adapts to battery housings of different thickness. The pressure balancing device can be mounted on battery housings of different thicknesses by means of a second sealing element that has a grooved structure. Thus, the sealing feature of the pressure balancing device is preserved in the battery housings of different thicknesses.

Another purpose of the invention is to align at least one spring at the center of the flow channel by means of at least one connecting element. Thus, the cover moves in the center of the flow channel during opening.

To meet the above-mentioned purposes, the invention is a pressure balancing device used for balancing the pressure in the batteries, comprising: a body that is mounted on an opening of the battery housing and having a flow channel in its interior allowing fluid passage; a cover positioned on the body, which prevents the fluid passage between the interior of the battery housing and the exterior environment by closing the flow channel when the internal pressure of the battery housing and the external environment pressure are in balance, and which provides fluid passage by opening the flow channel when a difference occurs between the internal pressure of the battery housing and the external environment pressure, in that, it comprises at least one spring that allows the working pressure of the pressure balancing device to be determined in direct proportion to the spring constant, and which enables the cover to close automatically when the internal pressure of the battery housing and the external environment pressure is balanced.

The structural and characteristic features and all advantages of the invention will be clarified with the detailed description of the figures and the following description. Therefore, the evaluation should be done by taking into account these figures and detailed explanation.

Brief Description of Figures

Figure 1 : is the cross-sectional view of the pressure balancing device when the pressure between the battery housing and the external environment is in balance.

Figure 2: is the cross-sectional view of the pressure balancing device when the internal pressure of the battery housing is higher than the environment pressure.

Figure 3: is the cross-sectional view of the alternative embodiment of the pressure balancing device.

Descriptor) of Part References

Parga Referanslarinin Aciklamasi

A. Pressure balancing device

10. Battery housing

20. Body

22. Flow channel

24. Groove

26. Protrusion

30. Cap

32. Connection element

34. Pin 40. First sealing element

50. Second sealing element

60. Spring

70. Locking ring

80. Membrane

90. Protection cover

Detailed Description of the Invention

In this detailed description, the preferred embodiments of the pressure balancing device (A) disclosed under the invention have been discloed solely fort he purpose of a better understanding of the subject.

Referring to Figure 1 , the pressure balancing device (A) is mounted in an opening located in the battery housing (10). The pressure balancing device (A) provides balancing of the internal pressure of the battery housing (10) and the external pressure. Here, the external environment defines the environment outside the battery housing (10). External environment pressure also refers to atmospheric pressure in a general sense or the pressure of the environment in which the battery is located.

The mounting of the pressure balancing device (A) to the battery housing (10) is provided by means of the body (20). The connection section of the body (20) may be in the form of a threaded, snap-fit, bayonet, or other connection types in the state of the art. The body (20) is mounted to the battery housing (10) without the need for any mounting equipment, thanks to the connection section. There is a flow channel (22) inside the body (20) that allows fluid to pass through.

The pressure balancing device (A) includes a cap (30) located on the body (20) and covering the flow channel (22). When the internal pressure of the battery housing (10) is in balance with the external pressure, the cap (30) closes the flow channel (22). Thus, the flow of fluid between the interior of the battery housing (10) and the external environment is prevented. Referring to Figure 2, when a difference between the internal pressure of the battery housing (10) and the external environment pressure occurs, the cover (30) moves away from the body (20) with the effect of the internal pressure and the flow channel (22) opens. Thus, the internal fluid is discharged and the external pressure is equalized with the internal pressure of the battery housing (10). The surface of the cap (30) facing the flow channel (22) has a concave form. The amount of fluid discharged per unit time increases by means of the concave form of the cover (30). The cover (30) has at least one connection element (32). The connection element (32) extends within the flow channel (22). In a preferred embodiment of the invention, the cap (30) and at least one connection element (32) are integrated structures. In another preferred embodiment of the invention, the cap (30) and at least one connection element (32) are manufactured separately and then assembled to each other.

At least one first sealing element (40) is placed in at least one groove (24) located on the body (20). At the end of the groove (24) there is at least one protrusion (26). The first sealing element (40) is prevented from coming out of the groove (24) during fluid discharge by means of the protrusion (26). The first sealing element (40) provides the sealing of the flow channel (22) when the cap (30) is in closed position. In preffered embodiments of the invention, the first sealing element (40) is located between the body (20) and the cap (30). The first sealing element (40) has a “V” shaped form. In preffered embodiments of the invention, the pointed tip of the “V” shape is positioned to face the flow channel (22). The placement of the first sealing element (40) in this way ensures that the amount of fluid discharged per unit time increases. Another advantage of this placement is that the pressure balancing device (A) successfully passes the tests applied in the protection ratings IP65, IP66, IP67, IP68 and IP69K, which represent the sealing protection ratings.

There is at least a second sealing element (50) between the battery housing (10) and the body (20). The second sealing element (50) provides sealing between the battery housing (10) and the body (20). In preferred embodiments of the invention, the second sealing element (50) has a grooved structure. In this way, the second sealing element (50) can be used in the thicknesses of the battery housing (10) within a predetermined thickness range. Therefore, sealing is provided at different predetermined thicknesses of the battery housing (10) thicknesses without changing the second sealing element Automatic closing of the cap (30) when the internal pressure of the battery housing (10) and the external pressure are balanced is provided by at least one spring (60). The spring (60) surrounds the connection element (32). Thus, the alignment of the spring (60) in the center of the flow channel (22) is ensured. The spring (60) centered by the connection element (32) ensures that the cap (30) is opened without wobbling during fluid discharge. Therefore, the cap (30) moves in the center of the flow channel (22). In the pressure balancing device (A) which is the subject of the invention, the pressure range which the cap (30) will be opened can only be determined depending on the spring constant of the spring (60). In this way, it is ensured that the pressure balancing device (A) operates independently of all other variables in the predetermined pressure range. Variances in predetermined working pressure ranges that may occur due to different production times of pressure balancing devices (A) and/or variances in the working pressure ranges of the same pressure balancing device (A) due to time depending aging are prevented. In a preferred embodiment of the invention, the spring (60) is in helical form.

The lock ring (70) ensures that the spring (60) is fixed by compression. The lock ring (70) is mounted to at least one pin (34) on the connection element (32).

In alternative embodiments of the invention, the pressure balancing device (A) includes at least one membrane (80). The membrane (80) is placed on the cap (30) and the membrane (80) provides gas passage from the inside of the battery housing (10) to the outside when the cap (30) is closed. The membrane (80) allows gas passage and does not allow liquid passage. The pressure balancing device includes at least one protection cover (90) to protect the membrane (A) (80) from external effects.