JP7730865B2 - battery pack - Google Patents

Description

This technology relates to battery packs.

Japanese Patent Application Laid-Open Publication No. 08-121444 (Patent Document 1) discloses a hook-and-loop type connection mechanism for attaching the device body to a base.

JP 2016-143554 A (Patent Document 2) discloses a mechanism for storing the external connection terminals of an energy storage module, which includes an opening/closing cover and a bearing member that rotatably supports the opening/closing cover.

Japanese Patent Application Publication No. 08-121444 JP 2016-143554 A

In cases that house terminal members for electrically connecting battery cells in a battery pack to devices external to the battery pack, there is a need to simplify the manufacture of a locking mechanism that keeps the case closed while improving its durability.

In addition, from a different perspective than the above, there is a need to improve the operability of the locking mechanism.

One aspect of the present technology provides the following assembled battery:

[1] An assembled battery comprising: a plurality of battery cells; terminal members electrically connected to the plurality of battery cells; and an openable/closable case that houses the terminal members. The case has a holder that holds the terminal members, a cover that is rotatable about a first axis relative to the holder, and a locking mechanism that keeps the case closed. The case is opened and closed by rotating the cover about the first axis. The locking mechanism includes a fixed claw that is integrated with a first member that constitutes one of the holder and cover, and a movable claw that is integrated with a second member that constitutes the other of the holder and cover. The movable claw includes a tip claw that engages with the fixed claw and an operating portion for moving the tip claw. The second member faces the operating portion and has a gap for moving the operating portion. The portion of the second member that faces the gap has an uneven shape that includes a protrusion that defines the minimum width of the gap and a recess that exposes the tip claw when viewed from above the gap.

[2] The battery pack described in [1], in which the fixed claws are integrally molded with the holder portion and the movable claws are integrally molded with the cover portion.

[3] The battery pack described in [1] or [2], wherein the locking mechanism includes a first locking mechanism and a second locking mechanism aligned in a direction parallel to the first axis, each of the first locking mechanism and the second locking mechanism including a fixed claw and a movable claw, and the locking by the locking mechanism is released by pinching the operating portions of the movable claws of the first locking mechanism and the second locking mechanism from the direction of the first axis.

[4] The battery pack described in any one of [1] to [3], wherein the holder portion has a limiting protrusion that prevents the cover portion from rotating in the opening direction beyond a predetermined angle.

[5] A battery pack described in any one of [1] to [4], wherein the movable claw is integrated with the second member via the rod-shaped portion, and the tip claw portion and the operating portion are separately provided on both sides of the rod-shaped portion when viewed in the axial direction of the rod-shaped portion.

According to one aspect of the present technology, excessive deformation of the movable claw is suppressed by providing a convex portion that defines the minimum width of the gap, and a concave portion that exposes the tip claw portion when viewed from above the gap makes it easy to manufacture the integrated movable claw and second member. As a result, it is possible to provide a battery pack in which the case that houses the terminal members is easy to manufacture and is highly durable.

FIG. 2 is a perspective view showing a battery pack. FIG. 2 is a perspective view showing the internal structure of the battery pack. FIG. 2 is a perspective view showing the configuration of a battery cell. FIG. 2 is a perspective view showing an open state of a case that stores terminal members. FIG. 2 is a perspective view showing a case that houses terminal members in a closed state. FIG. 10 is an enlarged perspective view showing details of a locking mechanism that keeps the case closed. 10 is a side view showing an opening/closing mechanism for opening and closing the case and a holding mechanism for maintaining the case in an open state. FIG. 8 is a perspective view showing a state in which the cover portion of the case has been rotated in the closing direction from the state shown in FIG. 7. FIG. FIG. 10 is a side view showing a modified example of the holding mechanism.

The following describes an embodiment of the present technology. Note that the same or corresponding parts are designated by the same reference symbols, and their descriptions may not be repeated.

Note that in the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the embodiments described below, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects mentioned in the present embodiments.

In this specification, the terms "comprise," "include," and "have" are open-ended. In other words, when a certain feature is included, other features may or may not be included.

In addition, when geometric terms and terms expressing positional or directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

In this specification, "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "electrode" may collectively refer to positive and negative electrodes.

In this specification, "battery cells" are not necessarily limited to rectangular cells, but may also include cells of other shapes, such as cylindrical cells.

In addition, the "battery pack" in this specification can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of the "battery pack" in this specification is not limited to in-vehicle use.

Figure 1 is a perspective view showing the configuration of the battery pack 1. Figure 2 is a perspective view showing the internal structure of the battery pack 1.

As shown in Figures 1 and 2, the battery pack 1 includes a battery cell 100, an end plate 200, a restraining member 300, a cover member 400, a terminal member 500, and a case 600.

A number of battery cells 100 are stacked in the Y direction to form the stack 10. Separators (not shown) are interposed between the battery cells 100. The stack 10 is sandwiched between two end plates 200. In this embodiment, the stack 10 is pressed against the end plates 200 and restrained between the two end plates 200.

The end plates 200 are provided at both ends of the stack 10 in the Y direction. The end plates 200 are fixed to a base such as a pack case that houses the battery pack 1. The end plates 200 are made of, for example, aluminum or iron.

The restraining members 300 are provided on both ends of the stack 10 and the end plates 200 in the X direction. The stack 10 and end plates 200 are arranged side by side, and a compressive force in the Y direction is applied to the stack 10 and end plates 200. The restraining members 300 are engaged with the end plates 200, and the compressive force is then released, causing a tensile force to act on the restraining members 300 connecting the two end plates 200. In reaction to this, the restraining members 300 press the two end plates 200 in a direction that brings them closer together. As a result, the restraining members 300 restrain the stack 10 in the Y direction.

The cover member 400 is provided to cover the stack 10 from the Z direction. The cover member 400 is made of an electrically insulating resin material.

The terminal members 500 are provided to electrically connect the stack 10 to an external terminal (not shown). The terminal members 500 are arranged on both sides of the stack 10 in the Y direction. The terminal members 500 are made of plate-shaped conductors. The terminal members 500 are electrically connected to at least one battery cell 100 out of the multiple battery cells 100.

The case 600 houses the terminal member 500. In the example shown in Figures 1 and 2, the case 600 is located at the end of the stack 10 in the Y direction. The case 600 includes a holder portion 610 (first member) and a cover portion 620 (second member).

The holder portion 610 is insulating. The holder portion 610 is connected to the end plate 200 by a known method such as bolt fastening. The terminal member 500 is fixed to the holder portion 610. In other words, the holder portion 610 holds the terminal member 500.

The cover part 620 is rotatable around the X-axis (first axis) relative to the holder part 610. The case 600 is opened and closed by rotating the cover part 620 around the X-axis.

Figure 3 is a perspective view showing the configuration of the battery cell 100. As shown in Figure 3, the battery cell 100 includes an electrode terminal 110, a housing 120, and a gas release valve 130.

The electrode terminal 110 is formed on the housing 120. The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112. The positive electrode terminal 111 and the negative electrode terminal 112 are arranged side by side in the X direction.

The housing 120 is a container that houses an electrode assembly and electrolyte (not shown). The housing 120 has a roughly rectangular parallelepiped shape. The housing 120 is made of aluminum, an aluminum alloy, iron, or an iron alloy such as stainless steel.

The gas exhaust valve 130 ruptures when the pressure inside the housing 120 reaches or exceeds a predetermined value. This allows the gas inside the housing 120 to be exhausted outside the housing 120.

Figures 4 and 5 are perspective views showing the case 600 in the open and closed states, respectively. As shown in Figures 4 and 5, the case 600 includes a locking mechanism 630. The locking mechanism 630 includes a fixed claw 631 and a movable claw 632. The locking mechanism 630 maintains the case 600 in the closed state.

The fixed claw 631 is integrated with the holder portion 610, and the movable claw 632 is integrated with the cover portion 620. However, the scope of the present technology is not limited to this, and the fixed claw 631 may be integrated with the cover portion 620, and the movable claw 632 may be integrated with the holder portion 610. In this specification, "integration" typically refers to integral molding of resin, but the scope of the present technology is not limited to this, and for example, the holder portion 610 and the fixed claw 631 may be formed separately and then fixed together by adhesive or the like.

The fixed claw 631 is provided to protrude from the side of the holder portion 610. The movable claw 632 includes a tip claw portion 632A that engages with the fixed claw 631, an operating portion 632B for moving the tip claw portion 632A, and a rod-shaped portion 632C.

As shown in Figures 4 and 5, a pair of locking mechanisms 630 (first locking mechanism and second locking mechanism) are provided, aligned in a direction parallel to the X-axis (first axis). Each of the pair of locking mechanisms 630 includes a fixed claw 631 and a movable claw 632.

By clamping the operating portions 632B of the movable claws 632 of a pair of locking mechanisms 630 along the X direction, the locking mechanism 630 is released. This results in a locking mechanism 630 that is easy to operate.

The movable claw 632 is integrated with the holder portion 610 via the rod-shaped portion 632C. The rod-shaped portion 632C is arranged so that its axial direction is along the Y direction. When the movable claw 632 is viewed from the Y direction, the tip claw portion 632A is located on one side in the Z direction (the lower side in the figure), and the operating portion 632B is located on the other side in the Z direction (the upper side in the figure). In other words, the tip claw portion 632A and the operating portion 632B are separately located on either side of the rod-shaped portion 632C when viewed from the axial direction of the rod-shaped portion 632C.

Figure 6 is an enlarged perspective view showing the details of the locking mechanism 630. As shown in Figure 6, a gap 621 is formed in the cover portion 620 facing the operating portion 632B of the movable claw 632. The portion of the cover portion 620 facing the gap 621 has an uneven shape. More specifically, the uneven shape includes protrusions 622 and recesses 623. The protrusions 622 are formed on both sides of the recesses 623. The recesses 623 are formed so as to be sandwiched between the protrusions 622. The protrusions 622 and the recesses 623 are formed so as to be adjacent to each other in the Y direction.

The formation of the gap 621 allows the operating portion 632B of the movable claw 632 to move in the X direction. When the operating portion 632B is pushed toward the cover portion 620, the rod-shaped portion 632C is slightly twisted and deformed, disengaging the tip claw portion 632A from the fixed claw 631. This releases the closed state maintained by the locking mechanism 630.

The convex portions 622 define the minimum width of the gap 621. In the structure shown in FIG. 6, the length of the operating portion 623B in the Y-axis direction is longer than the length of the concave portions 623 located between the convex portions 622 in the Y-axis direction. In this way, the operating portion 632B of the movable claw 632 abuts against the convex portions 622, defining the movable range of the operating portion 632B in the X-axis direction and suppressing excessive deformation of the rod-shaped portion 632C, thereby suppressing damage to the movable claw 632. However, the scope of the present technology is not limited to that shown in FIG. 6, and the structure for abutting the operating portion 623B against the convex portions 622 is not limited to the above example.

The recess 623 is formed so that the tip claw portion 632A is exposed when the gap 621 is viewed from the Z direction (from above in Figure 6), i.e., so that the tip claw portion 632A is visible when the gap 621 is viewed from above. This makes it easier to prepare a molding die for integrally molding the cover portion 620 and the movable claw 632, facilitating the production of the integrated cover portion 620 and movable claw 632.

In this way, the battery pack 1 according to this embodiment makes it possible to easily manufacture the locking mechanism 630 while improving its durability.

Next, using Figures 7 to 9, we will explain the opening and closing mechanism 640 that opens and closes the case 600, and the holding mechanism 650 that keeps the case 600 open.

Figure 7 is a side view showing the opening/closing mechanism 640 and the holding mechanism 650, and Figure 8 is a perspective view showing the state in which the cover part 620 has been rotated in the closing direction from the state shown in Figure 7.

As shown in Figures 7 and 8, the opening/closing mechanism 640 includes a shaft portion 641 and a cylindrical portion 642. The shaft portion 641 fits into the cylindrical portion 642. The case 600 is opened and closed by relative rotation between the shaft portion 641 and the cylindrical portion 642. The shaft portion 641 and the cylindrical portion 642 are formed to extend along the X direction.

In the example shown in Figures 7 and 8, the shaft portion 641 is formed on the holder portion 610, and the tubular portion 642 is formed on the cover portion 620. However, the scope of the present technology is not limited to this, and the shaft portion 641 may be formed on the cover portion 620, and the tubular portion 642 may be formed on the holder portion 610.

The holding mechanism 650 includes a protrusion 651 (first protrusion) and an engagement portion 652. The protrusion 651 protrudes in the X direction from the holder portion 610. The engagement portion 652 is integral with the cover portion 620. In the example shown in Figure 7, the engagement portion 652 is part of the cover portion 620.

As shown in Figure 7, the protrusion 651 and the engagement portion 652 engage, maintaining the open state of the case 600 in the state shown in Figure 7 (first open angle).

The holder portion 610 has a limiting protrusion 611. When the open angle of the cover portion 620 is further increased from the state shown in Figure 7 (when the cover portion 620 is rotated clockwise in the figure), the cover portion 620 comes into contact with the limiting protrusion 611, preventing the cover portion 620 from further rotating in the opening direction. This prevents excessive rotation of the opening/closing mechanism 640 and protects the case 600.

When the cover part 620 is rotated in the open direction from the state shown in Figure 8 to the state shown in Figure 7, the cover part 620 deforms slightly around the engagement part 652, bending in the X direction, and can overcome the protrusion 651 to reach the state shown in Figure 7.

Figure 9 is a side view showing a modified example of the holding mechanism 650. In the example of Figure 9, the shape of the engagement portion 652 is different from the examples of Figures 7 and 8.

In the modified example shown in Figure 9, the engagement portion 652 includes a first leg portion 652A, a second leg portion 652B, a bridge portion 652C, and a protrusion 652D (second protrusion). The first leg portion 652A and the second leg portion 652B protrude radially outward from the cylindrical portion 642. The bridge portion 652C connects the first leg portion 652A and the second leg portion 652B in the circumferential direction while forming a gap between the bridge portion 652C and the cylindrical portion 642. The protrusion 652D protrudes radially outward from the bridge portion 652C. The engagement of the protrusion 652D with the protrusion 651 maintains the open state of the case 600 in the state shown in Figure 9 (first open angle). When the protrusion 652D overcomes the protrusion 651, the bridge portion 652C deforms slightly so as to bend radially inward.

In the retention mechanism 650 of this embodiment, the structure of the protrusion 651 and the engagement portion 652 is simple, and the open angle at which the case 600 is kept open can be easily changed simply by adjusting the position of the protrusion 651. Furthermore, the required retention force (torque) for keeping the case 600 open can be obtained simply by adjusting the configuration of the protrusion 651 (shape, protrusion height, etc.) or the configuration of the engagement portion 652 (for example, the shape and protrusion height of the protrusion 652D, etc.).

In this way, the battery pack 1 according to this embodiment makes it possible to easily manufacture the holding mechanism 650 that maintains the case 600 in an open state at a predetermined angle, while improving its holding force.

The above describes embodiments of the present technology, but the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims.

1 Battery pack, 10 Stacked body, 100 Battery cell, 110 Electrode terminal, 111 Positive electrode terminal, 112 Negative electrode terminal, 120 Housing, 130 Gas release valve, 200 End plate, 300 Restraint member, 400 Cover member, 500 Terminal member, 600 Case, 610 Holder portion, 611 Restricting protrusion, 620 Cover portion, 621 Gap, 622 Convex portion, 623 Concave portion, 630 Locking mechanism, 631 Fixed claw, 632 Movable claw, 632A Tip claw portion, 632B Operating portion, 632C Rod-shaped portion, 640 Opening/closing mechanism, 641 Shaft portion, 642 Cylinder portion, 650 Holding mechanism, 651 Protrusion, 652 Engagement portion, 652A First leg portion, 652B Second leg portion, 652C Bridge section, 652D protrusion.

Claims (5)

A plurality of battery cells;
terminal members electrically connected to the plurality of battery cells;
an openable and closable case for accommodating the terminal member;
the case has a holder portion that holds the terminal member, a cover portion that is rotatable about a first axis relative to the holder portion, and a locking mechanism that keeps the case closed, and the case is opened and closed by rotating the cover portion about the first axis;
the locking mechanism includes a fixed claw integrated with a first member constituting one of the holder portion and the cover portion, and a movable claw integrated with a second member constituting the other of the holder portion and the cover portion,
The movable claw includes a tip claw portion that engages with the fixed claw and an operating portion for moving the tip claw portion,
the second member faces the operating unit and has a gap for moving the operating unit;
a portion of the second member facing the gap has an uneven shape including a protrusion that defines a minimum width of the gap and a recess that exposes the tip claw portion when viewed from above the gap. The battery pack described in claim 1, wherein the fixed claws are integrally molded with the holder portion, and the movable claws are integrally molded with the cover portion. the locking mechanism includes a first locking mechanism and a second locking mechanism aligned in a direction parallel to the first axis, each of the first locking mechanism and the second locking mechanism including the fixed claw and the movable claw;
3. The battery pack according to claim 1, wherein the locking by the locking mechanisms is released by pinching the operating portions of the movable claws of the first locking mechanism and the second locking mechanism from the direction of the first axis. The battery pack described in claim 1 or claim 2, wherein the holder portion has a limiting protrusion that prevents the cover portion from rotating in the opening direction beyond a predetermined angle. the movable claw is integrated with the second member via a rod-shaped portion,
3. The battery pack according to claim 1, wherein the tip claw portion and the operating portion are separately provided on both sides of the rod-shaped portion when viewed in the axial direction of the rod-shaped portion.