Drain valve for battery box, battery, electric apparatus, and drainage method

1 . A drain valve, comprising:

a sealing member, wherein the sealing member is configured to be disposed on an outer side of a drain outlet of a battery box; and

an expansion member, wherein the expansion member is disposed on a side of the sealing member facing the drain outlet, and the expansion member is configured to expand after absorbing water to extrude an edge of the sealing member, causing the edge of the sealing member to bend and deform, to move in a direction leaving an inner side of the drain outlet.

2 . A battery, comprising:

a battery box, wherein the battery box is provided with a drain outlet communicating with an inner side and outer side of the battery box; and

the drain valve according to claim 1 , wherein the drain valve is connected to the drain outlet to close the drain outlet.

3 . An electric apparatus, comprising:

the battery according to claim 2 .

4 . The drain valve according to claim 1 , further comprising:

a fixing assembly, wherein the fixing assembly is configured to fix the drain valve to the battery box.

5 . The drain valve according to claim 4 , wherein:

the fixing assembly comprises a connecting member, a fastening member, and a bearing member, wherein a first side of the connecting member is attached to the outer side of the drain outlet, the fastening member is connected to both the connecting member and the inner side of the drain outlet, the bearing member is connected to a second side of the connecting member facing away from the first side, and the bearing member and the second side of the connecting member define a closed space; and

the connecting member, the fastening member, and the bearing member are respectively provided with a first through hole, a second through hole, and a third through hole that communicate with each other, the sealing member is disposed in the closed space, and the expansion member is opposite the first through hole.

6 . The drain valve according to claim 5 , wherein:

an accommodating portion is recessed on a surface of the bearing member facing the second side of the connecting member, a connecting pillar extends from an inner wall of the bearing member in a direction facing the connecting member, the connecting pillar runs through the sealing member and is connected to the connecting member, and the surface of the second side of the connecting member abuts against an edge of the accommodating portion.

7 . The drain valve according to claim 5 , wherein:

a penetrating pillar protrudes from the first side of the connecting member, the penetrating pillar runs through the drain outlet and is partially located on the inner side of the drain outlet, and the penetrating pillar is provided with an external thread; and

the fastening member is provided with an internal thread fitting with the external thread, and a turn of edge of the fastening member close to a side of the bearing member abuts against a turn of the inner side of the drain outlet.

8 . The drain valve according to claim 5 , further comprising:

a sealing ring, wherein the sealing ring is an elastic member, the sealing ring is disposed in a turn of groove in the first side of the connecting member, and a surface of the sealing ring facing away from the turn of groove abuts against a turn of the outer side of the drain outlet.

9 . The drain valve according to claim 1 , wherein:

the sealing member is provided with a concave portion on the side facing the drain outlet, the concave portion is configured for accommodating the expansion member, and the expansion member expands to extrude the concave portion to move in the direction leaving the inner side of the drain outlet.

10 . The drain valve according to claim 9 , wherein:

the expansion member is adhered and coupled in the concave portion of the sealing member; and/or

the expansion member and the sealing member are integrally formed.

11 . The drain valve according to claim 9 , wherein:

the sealing member is plate-shaped, a plurality of convex strips are formed on a side surface of the sealing member, and adjacent two of the plurality of convex strips cooperate to define the concave portion.

12 . The drain valve according to claim 11 , wherein:

the plurality of convex strips are ring-shaped, the plurality of convex strips are concentrically spaced apart, and a center of the ring overlaps an orthographic projection of a center of the drain outlet.

13 . The drain valve according to claim 11 , wherein:

extension directions of the plurality of convex strips are consistent, and a first part of the plurality of convex strips are correspondingly located on one side of a center of the drain outlet, and a second part of the plurality of convex strips are correspondingly located on an other side of the center of the drain outlet.

14 . The drain valve according to claim 13 , wherein:

a distance between adjacent two of the plurality of convex strips in a first part of the plurality of convex strips is equal to a distance between adjacent two of the plurality of convex strips in a second part of the plurality of convex strips; and/or

the first part of the plurality of convex strips and the second part of the plurality of convex strips are symmetrical, and a distance between the first part of the plurality of convex strips and the second part of the plurality of convex strips is greater than the distance between adjacent two of the plurality of convex strips in the first part of the plurality of convex strips.

15 . An automatic drainage method applied to a drain valve,

wherein the drain valve is mounted on an outer side of a drain outlet of a battery box to close the drain outlet, and the drain valve comprises:

a sealing member, wherein the sealing member is disposed on the outer side of the drain outlet; and

an expansion member, wherein the expansion member is disposed on a side of the sealing member facing the drain outlet, and the expansion member is configured to expand after absorbing water to extrude an edge of the sealing member to move in a direction leaving an inner side of the drain outlet;

the automatic drainage method comprising:

enabling a liquid in the battery box to come into contact with the expansion member of the drain valve;

expanding by the expansion member to extrude sealing members on two sides of the expansion member; and

bending edges of the extruded sealing members in a direction leaving the battery box to form gaps between the edges of the extruded sealing members and the battery box, wherein water is drained through the gaps.

16 . A drain valve, comprising:

a sealing member configured to be disposed on an outer side of a drain outlet of a battery box; and

an expansion member disposed on a side of the sealing member facing the drain outlet, wherein the expansion member is configured to expand after absorbing water to extrude an edge of the sealing member to move in a direction leaving an inner side of the drain outlet;

wherein:

the sealing member is provided with a concave portion on the side facing the drain outlet, the concave portion is configured for accommodating the expansion member, and the expansion member expands to extrude the concave portion to move in the direction leaving the inner side of the drain outlet; and

the sealing member is plate-shaped, a plurality of convex strips are formed on a side surface of the sealing member, and adjacent two of the plurality of convex strips cooperate to define the concave portion.