Explosion-proof pressure release valve of lithium battery

Abstract

The utility model relates to the technical field of lithium batteries, in particular to an anti-explosion pressure release valve of a lithium battery. Comprising a cylindrical valve body, a sealing groove is formed in the inner wall of the valve body, a sealing ring is arranged in the sealing groove, an inserting groove penetrating through the two sides of the valve body is formed in one end of the valve body, a piston is inserted into the valve body and is in sliding connection with the sealing ring, a protruding column is arranged at one end of the piston, and the diameter of the protruding column is smaller than that of the piston. Elastic pieces are arranged on the two sides of the end, away from the piston, of the protruding column, the elastic pieces are inserted into the inserting grooves, and a blocking plate is arranged on the inner side of the end, provided with the inserting grooves, of the valve body. Whether the internal pressure of the battery is abnormal or not can be judged by observing whether the piston moves outwards or not.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to an explosion-proof pressure relief valve for lithium batteries. Background Art

[0002] In order to prevent lithium batteries from exploding due to excessive internal pressure, it is generally necessary to install a pressure relief valve on the outer casing of the lithium battery. Patent application number 202222885224.8 discloses an explosion-proof pressure relief valve for square aluminum-cased lithium batteries. The valve comprises a valve aperture, an explosion-proof membrane, a circular ring, and a protective membrane. The entire explosion-proof membrane is circular, consisting of an outer annular flat base and a central spherical raised portion. A circular notch is engraved on the surface of the concave side of the raised portion, at the intersection of the circles where the flat base and the raised portion meet. When the internal pressure of the battery rises and reaches the tipping pressure, the raised portion of the explosion-proof membrane flips from concave to convex under the stress of the internal and external pressure differential. This change in the membrane's shape serves as a marker for identifying batteries with abnormal internal pressure. When the internal pressure of the battery continues to rise and reaches the bursting threshold, the membrane, under the stress, bursts and tears along the annular notch, allowing the accumulated gas in the battery to be discharged into the atmosphere, thereby preventing the battery from exploding. However, the abnormal battery pressure can only be detected when the internal and external pressure differential reaches a certain level, causing the raised portion of the explosion-proof membrane to bulge outward. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide a lithium battery explosion-proof pressure relief valve in response to the above-mentioned technical deficiencies.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is: a lithium battery explosion-proof pressure relief valve, including a valve body, the valve body is cylindrical, a sealing groove is provided on the inner wall of the valve body and a sealing ring is provided in the sealing groove, one end of the valve body is provided with a slot running through both sides thereof, the piston is inserted into the valve body and is slidingly connected to the sealing ring, one end of the piston is provided with a boss, the diameter of the boss is smaller than the diameter of the piston, and elastic sheets are provided on both sides of the end of the boss away from the piston, the elastic sheets are inserted into the slot, and a blocking plate is provided on the inner side of the end of the valve body with the slot.

[0005] To further optimize the technical solution, a plurality of second exhaust grooves are provided on the outer circumference of one end of the piston close to the boss. In a natural state, the second exhaust grooves are located on the side of the sealing ring close to the boss.

[0006] To further optimize the technical solution, a plurality of first exhaust grooves are provided on the inner wall of the valve body, and the first exhaust grooves are located on a side of the sealing ring away from the protruding column.

[0007] To further optimize the technical solution, a cap portion is provided on the outer side of one end of the valve body away from the slot.

[0008] Compared with the prior art, the present invention has the following advantages: a sealing ring is provided on the inner wall of the valve body, the piston is slidably connected to the sealing ring, a convex column is provided at one end of the piston, elastic sheets are provided on both sides of the convex column, and the elastic sheets are inserted into the slots on the valve body. When the pressure inside the battery increases, the piston will be pushed to move. By observing whether the piston moves outward, it can be determined whether the internal pressure of the battery is abnormal. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The figure is a structural diagram of a lithium battery explosion-proof pressure relief valve.

[0010] Figure 2 This is a cross-sectional view of a lithium battery explosion-proof pressure relief valve.

[0011] Figure 3 This is a schematic diagram of the installation of a lithium battery explosion-proof pressure relief valve.

[0012] In the figure: 1. valve body; 11. cap; 12. first exhaust groove; 13. blocking plate; 14. slot; 2. piston; 21. second exhaust groove; 22. elastic sheet; 3. sealing ring; 4. cover plate; 41. valve hole. DETAILED DESCRIPTION

[0013] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. Furthermore, descriptions of known structures and technologies are omitted in the following description to avoid unnecessary confusion regarding the concepts of the present invention.

[0014] Specific implementation method: Figure 1-3 As shown, a lithium battery explosion-proof pressure relief valve includes a valve body 1, which is cylindrical. A sealing groove is provided on the inner wall of the valve body 1 and a sealing ring 3 is provided in the sealing groove. One end of the valve body 1 is provided with a slot 14 running through both sides thereof. The piston 2 is inserted into the valve body 1 and is slidably connected with the sealing ring 3. There is a relatively small gap between the outer wall of the piston 2 and the inner wall of the valve body 1. A boss is provided at one end of the piston 2. The diameter of the boss is smaller than the diameter of the piston 2. Elastic sheets 22 are provided on both sides of the end of the boss away from the piston 2. A threaded hole penetrating into the piston 2 can be provided on the boss, and a through hole is provided in the middle of the elastic sheet 22. The elastic sheet 22 is fixed to the boss with a screw. The elastic sheet 22 is inserted into the slot 14 and can slide relative to the slot 14. A blocking plate 13 is provided on the inner side of the end of the valve body 1 where the slot 14 is provided. When the elastic sheet 22 is in a natural state, the side away from the piston 2 contacts the blocking plate 13, thereby limiting the position of the piston 2.

[0015] Furthermore, a plurality of second exhaust grooves 21 are provided on the outer circumference of the end of the piston 2 close to the boss. In a natural state, the second exhaust grooves 21 are located on the side of the sealing ring 3 close to the boss. When the second exhaust grooves 21 are provided, the length of the piston 2 can be longer, thereby improving the guiding performance.

[0016] Furthermore, a plurality of first exhaust grooves 12 are provided on the inner wall of the valve body 1 . The first exhaust grooves 12 are located on a side of the sealing ring 3 away from the boss. The first exhaust grooves 12 can improve the exhaust capacity.

[0017] Furthermore, a cap portion 11 is provided on the outer side of the end of the valve body 1 away from the slot 14. The pressure relief valve of the present application is installed on the cover plate 4 of the battery when in use. The cover plate 4 is provided with a valve hole 41. The outer diameter of the cap portion 11 is larger than the diameter of the valve hole 41. The valve body 1 is inserted into the valve hole 41. In the absence of the cap portion 11, the valve body 1 can be bonded to the valve hole 41 and the two are in a sealed state; in the presence of the cap portion 11, the cap portion 11 can be bonded or welded to the outer side of the cover plate 4 (i.e., Figure 3 The upper side of the middle part of the flange is provided), thereby increasing the firmness of the connection and the reliability of the seal.

[0018] Working principle: Combination Figure 2 As shown, when the pressure within the lithium battery increases, it pushes piston 2 upward, deforming elastic sheet 22 during this process. When the pressure rises above the allowable value, the lower end of piston 2 passes upward over sealing ring 3 (if a second exhaust groove 21 is provided, the upper end of second exhaust groove 21 passes upward over sealing ring 3). Gas is discharged from the gap between valve body 1 and piston 2, releasing the pressure. When the battery is operating, the user can determine the internal pressure of the battery based on the distance between the upper end of piston 2 and the upper end of valve body 1. For easier observation, the inner wall of valve body 1 can be painted with a gradient color. The gradient color ranges from the position of the upper end of piston 2 in the normal state to the position of the upper end of piston 2 in the pressure relief state. Within this range, the color gradually changes from bottom to top. The color corresponding to the upper end of piston 2 can be used to determine the internal pressure of the battery.

[0019] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lithium battery explosion-proof pressure relief valve, comprising a valve body (1), characterized in that: The valve body (1) is cylindrical, a sealing groove is provided on the inner wall of the valve body (1) and a sealing ring (3) is provided in the sealing groove, one end of the valve body (1) is provided with a slot (14) running through both sides thereof, the piston (2) is inserted into the valve body (1) and is slidably connected to the sealing ring (3), one end of the piston (2) is provided with a convex column, the diameter of the convex column is smaller than the diameter of the piston (2), and elastic sheets (22) are provided on both sides of the end of the convex column away from the piston (2), and the elastic sheet (22) is inserted into the slot (14), and a blocking plate (13) is provided on the inner side of the end of the valve body (1) provided with the slot (14).

2. The lithium battery explosion-proof pressure relief valve according to claim 1, characterized in that: A plurality of second exhaust grooves (21) are provided on the outer circumference of one end of the piston (2) close to the boss. In a natural state, the second exhaust grooves (21) are located on a side of the sealing ring (3) close to the boss.

3. The lithium battery explosion-proof pressure relief valve according to claim 1, characterized in that: A plurality of first exhaust grooves (12) are provided on the inner wall of the valve body (1), and the first exhaust grooves (12) are located on a side of the sealing ring (3) away from the protruding column.

4. A lithium battery explosion-proof pressure relief valve according to any one of claims 1 to 3, characterized in that: A cap portion (11) is provided on the outer side of one end of the valve body (1) away from the slot (14).

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