Battery pack

Abstract

To provide a battery pack which can secure an exhaust function even when a sufficient space is not available at the outside of a case of the battery pack.SOLUTION: A battery pack includes a battery, a case which houses the battery, and an exhaust valve which exhausts a gas generated by the battery to the outside of the case. The case has a wall part attached with the exhaust valve. The wall part is expanded in a first direction when a pressure in the case is increased by the gas. The exhaust valve has: a main part fixed to the wall part; and a movable part which is attached to the main part in a state where the movable part is biased in the first direction and may move in a second direction opposite to the first direction relative to the main part. The exhaust valve is opened by the movable part moving in the second direction relative to the main part. When the wall part is expanded in the first direction by the gas, a pressing member provided outside the battery pack moves the movable part in the second direction relative to the main part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a battery pack. [Background technology]

[0002] BACKGROUND ART Battery packs mounted on vehicles are known. For example, Japanese Patent Application Laid-Open No. 2017-33886 (Patent Document 1) discloses a pressure release mechanism for such battery packs.

[0003] The pressure release mechanism is composed of multiple pressure release holes formed in the wall, a rod-shaped valve support member arranged along the inner surface of the wall, and a truncated conical sealing valve supported by the valve support member and press-fit into the pressure release hole from inside the pack case. Both ends of the valve support member are connected to the wall by brackets. When pressure inside the pack case increases, the wall of the pack case bends and deforms into an arc, causing the sealing valve to move away from the pressure release hole. This opens the pressure release hole. When most of the gas has been discharged, the pack case returns to its original shape and closes the pressure release hole. This maintains a positive pressure inside the pack case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-33886 Summary of the Invention [Problem to be solved by the invention]

[0005] In the battery pack of Patent Document 1, if there is not enough space on the outside of the pack case for the wall to curve, there is a risk that the pressure cannot be released.

[0006] The present disclosure provides a battery pack that can ensure exhaust function even when there is not enough space outside the case of the battery pack. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, a battery pack includes a battery, a case that houses the battery, and an exhaust valve that exhausts gas generated by the battery to the outside of the case. The case has a wall to which the exhaust valve is attached. The wall swells in a first direction when pressure inside the case increases due to the gas. The exhaust valve has a main body fixed to the wall, and a movable part attached to the main body while being biased in the first direction and movable relative to the main body in a second direction opposite to the first direction. The exhaust valve opens when the movable part moves in the second direction relative to the main body. When the wall swells in the first direction due to the gas, a pressing member provided outside the battery pack moves the movable part in the second direction relative to the main body.

[0008] With this configuration, the direction in which the wall expands is opposite to the direction in which the movable part moves relative to the main body to open the exhaust valve, so that the battery pack can ensure its exhaust function even when there is not enough space outside the battery pack case. [Effects of the Invention]

[0009] According to the present disclosure, even if there is not enough space outside the case of the battery pack, the exhaust function can be ensured. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing a state in which the battery pack is attached to a vehicle body frame. [Figure 2] FIG. 2 is a diagram showing state transitions from FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0012] The battery pack described below is mounted on an electrically powered vehicle such as a hybrid vehicle that can run using at least one of the power of a motor and an engine, or an electric vehicle that runs using driving force obtained from electrical energy.

[0013] Fig. 1 is a diagram showing a state in which a battery pack is attached to a vehicle body frame. As shown in Fig. 1, a battery pack 100 is attached to a vehicle body frame 200. The vehicle body frame 200 has a floor portion 210. The floor portion 210 has a bottom surface 211.

[0014] Stud bolts 300A and 300B extend vertically downward (in the direction of DR12) from the bottom surface 211. The stud bolts 300A and 300B are spaced apart in the direction of DR2, which is perpendicular to the vertical direction (direction of DR1). The direction of DR2 corresponds to the width direction of the vehicle or the longitudinal direction of the vehicle.

[0015] The battery pack 100 is installed below the bottom surface 211 of the floor portion 210. The battery pack 100 is installed below the stud bolts 300A and 300B.

[0016] The battery pack 100 includes one or more batteries 110, a case 120, and exhaust valves 130A and 130B. The case 120 houses the battery 110. The exhaust valves 130A and 130B exhaust gas generated within the battery pack 100 to the outside of the case 120. More specifically, the exhaust valves 130A and 130B exhaust gas generated by the battery 110 to the outside of the case 120.

[0017] Case 120 includes wall 121 including the top surface of case 120, wall 122 including the bottom surface of case 120, walls 123 to 125 including the side surfaces of case 120, and a wall (not shown) on the back surface of wall 125. Walls 121 to 124 extend in directions perpendicular to the DR1 and DR2 directions. Wall 121 is located higher than wall 122. Exhaust valves 130A and 130B are attached to wall 121.

[0018] The top surface and the bottom surface are each the main surface of the case 120. In this example, the wall portion 123 and the wall portion 124 are in contact with the body frame 200. The wall portion 123 and the wall portion 124 are spaced apart in the DR2 direction.

[0019] The exhaust valves 130A and 130B have the same configuration. Each of the exhaust valves 130A and 130B has a main body 131 and a movable part 132. In this example, the movable part 132 is located above the main body 131.

[0020] The main body 131 is fixed to the wall 121. The movable part 132 is attached to the main body 131 in a state where it is biased vertically upward (in the direction of DR1). The movable part 132 is biased vertically upward by a spring or the like. The movable part 132 is configured to be movable relative to the main body 131. More specifically, the movable part 132 is movable relative to the main body 131 in the direction of DR11 and in the direction of DR12 (vertically downward), which is opposite to the direction of DR11.

[0021] The exhaust valves 130A, 130B are opened when the movable part 132 moves in the direction of DR12 (vertically downward) relative to the main body part 131. Specifically, this relative movement of the movable part 132 with respect to the main body part 131 forms a gas flow path (gap) between the main body part 131 and the movable part 132, connecting the space inside the case 120 with the space outside the case 120. In the state shown in FIG. 1, the movable part 132 is biased in the direction of DR11 (vertically upward), and therefore the exhaust valves 130A, 130B are closed.

[0022] Exhaust valve 130A is disposed directly below stud bolt 300A. More specifically, movable part 132 of exhaust valve 130A is disposed directly below stud bolt 300A. Movable part 132 of exhaust valve 130A is positioned in the direction of DR12 when viewed from stud bolt 300A.

[0023] Similarly, exhaust valve 130B is disposed directly below stud bolt 300B. More specifically, movable part 132 of exhaust valve 130B is disposed directly below stud bolt 300B. Movable part 132 of exhaust valve 130B is positioned in the direction of DR12 when viewed from stud bolt 300B.

[0024] Fig. 2 is a diagram showing the state transition from Fig. 1. In detail, Fig. 2 is a diagram showing a state in which the battery pack 100 is swollen due to gas generated within the battery pack 100.

[0025] As shown in Fig. 2, the battery pack 100 bulges at least in the direction of DR11 (vertically upward). Specifically, the case 120 bulges at least in the direction of DR11. More specifically, the wall 121 of the case 120 bulges in the direction of DR11. Specifically, the wall 121 is deformed in an arc shape. More specifically, the wall 121 is curved so that the central portion of the wall 121 protrudes in the direction of DR11.

[0026] When gas is generated inside the case 120 and the wall portion 121 begins to bulge in the direction of DR11, the exhaust valves 130A, 130B provided on the wall portion 121 move in the direction of DR11. The exhaust valves 130A, 130B rise. That is, the exhaust valves 130A, 130B move toward the bottom surface 211 of the floor portion 210. Thereafter, the exhaust valve 130A comes into contact with the tip of the stud bolt 300A. The exhaust valve 130B comes into contact with the tip of the stud bolt 300B.

[0027] When the wall portion 121 further expands in the direction of DR11, the movable portion 132 of the exhaust valve 130A is pushed by the stud bolt 300A and moves in the direction of DR12 relative to the main body portion 131 of the exhaust valve 130A. Specifically, the movable portion 132 of the exhaust valve 130A is pushed down by the tip of the stud bolt 300A. Similarly, the movable portion 132 of the exhaust valve 130B is pushed by the stud bolt 300B and moves in the direction of DR12 relative to the main body portion 131 of the exhaust valve 130B. Specifically, the movable portion 132 of the exhaust valve 130B is pushed down by the tip of the stud bolt 300B. In this way, the stud bolts 300A and 300B function as pressing members that press the movable portion 132.

[0028] When the movable part 132 of the exhaust valve 130A is pushed down, the exhaust valve 130A opens, as described above. Similarly, when the movable part 132 of the exhaust valve 130B is pushed down, the exhaust valve 130B opens. When the exhaust valves 130A and 130B open, the gas 900 inside the battery pack 100 is exhausted to the outside of the battery pack 100 through the exhaust valves 130A and 130B.

[0029] When the gas 900 is discharged, the swelling of the battery pack 100 is eliminated or reduced. As a result, the movable parts 132 of the exhaust valves 130A, 130B move toward the DR11 relative to the main body part 131. This movement causes the exhaust valves 130A, 130B to transition from an open state to a closed state.

[0030] As described above, the battery pack 100 includes the battery 110, the case 120 that houses the battery 110, and the exhaust valves 130A and 130B that exhaust gas 900 generated by the battery 110 to the outside of the case 120. The case 120 has a wall 121 to which the exhaust valves 130A and 130B are attached. When the pressure inside the case 120 increases due to the gas 900, the wall 121 expands in the direction of DR11 (first direction).

[0031] The exhaust valves 130A, 130B have a main body 131 fixed to the wall 121, and a movable part 132 attached to the main body 131 while being biased in the direction of DR11 and movable in a direction of DR12 (second direction) opposite to the direction of DR11 relative to the main body 131. The exhaust valves 130A, 130B are opened when the movable part 132 moves in the direction of DR12 relative to the main body 131. When the wall 121 expands in the direction of DR11 due to the gas 900, the movable part 132 moves in the direction of DR12 relative to the main body 131 by the stud bolts 300A, 300B provided on the outside of the battery pack 100.

[0032] With this configuration, when the wall portion 121 bulges in the direction of DR11 due to the gas 900, the stud bolts 300A and 300B move the movable portions 132 of the exhaust valves 130A and 130B in a direction (DR12 direction) opposite to the bulging direction (DR11 direction) of the wall portion 121 relative to the main body portion 131. As a result, the gas 900 inside the battery pack 100 is discharged to the outside of the battery pack 100 through the exhaust valves 130A and 130B.

[0033] Thus, with battery pack 100, the direction in which wall portion 121 expands is opposite to the direction in which movable portion 132 moves relative to main body portion 131 to open exhaust valves 130A, 130B. Therefore, with battery pack 100, even if there is not enough space outside case 120 of battery pack 100, exhaust function can be ensured.

[0034] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0035] 100 battery pack, 110 battery, 120 case, 121, 122, 123, 124, 125 wall section, 130A, 130B exhaust valve, 131 main body section, 132 moving section, 200 body frame, 210 floor section, 211 bottom surface, 300A, 300B stud bolt, 900 gas.

Claims

[Claim 1] A battery pack, A battery, a case for accommodating the battery; an exhaust valve for discharging gas generated by the battery to the outside of the case, the case has a wall to which the exhaust valve is attached, the wall portion expands in a first direction when the pressure inside the case increases due to the gas; The exhaust valve is a main body portion fixed to the wall portion; a movable portion attached to the main body portion in a state where the movable portion is biased in the first direction and movable relative to the main body portion in a second direction opposite to the first direction; The movable portion moves in the second direction relative to the main body portion to assume an open state, When the wall portion expands in the first direction due to the gas, a pressing member provided outside the battery pack moves the movable portion in the second direction relative to the main body portion.

Images