JP2024146501A - Battery unit - Google Patents

Abstract

[Problem] To improve the strength of a battery unit against impacts from above. [Solution] A battery unit is disposed between two side members and two cross members of the vehicle. The battery unit includes a battery pack that supplies electricity to the vehicle, a protective cover that covers the battery pack above the battery pack, and a skeleton frame that is positioned below the protective cover, spans the two cross members, is welded to the protective cover, and is fastened to the two cross members. [Selected Figure] Figure 3

Description

The present invention relates to a battery unit for a vehicle.

Vehicles such as hybrid vehicles (HVs) and electric vehicles (EVs) are equipped with a battery unit that supplies electricity to the vehicle. The battery unit has a battery pack. Known vehicles of this type include those in which a protective cover is provided on the battery pack (see, for example, Patent Document 1) and those in which a framework member is provided across two cross members (see, for example, Patent Document 2).

JP 2012-84340 A JP 2017-136909 A

Conventional technology only encases the battery pack with a cover, which means the battery unit is weak in terms of resistance to impacts from above.

The present invention was made in consideration of the above, and one of its objectives is to improve the strength of the battery unit against impacts from above.

The battery unit according to the present invention is a battery unit disposed between two side members provided on a vehicle and two cross members provided on the vehicle, and includes a battery pack that supplies electricity to the vehicle, a protective cover that covers the battery pack above the battery pack, and a skeleton frame that is located below the protective cover, spans the two cross members, is welded to the protective cover, and is fastened to the two cross members.

With this configuration, the skeleton frame is welded to the protective cover and fastened to the two cross members, improving the strength (resistance) of the battery unit against impacts from above.

The battery unit is, for example, arranged in a direction intersecting the vertical direction with the battery pack and includes a control device that controls the battery pack, and the protective cover has a first cover member that covers the battery pack above the battery pack and a second cover member that covers the control device above the control device, and at least one of the skeletal frames is provided on each of the first cover member and the second cover member.

With this configuration, the protective cover is divided into at least a first cover member that covers the battery pack and a second cover member that covers the control device, so that when repairing the control device, only the second cover member can be removed to perform the work. This improves the ease of working on the battery unit.

In the battery unit, for example, a portion of the first cover member and a portion of the second cover member overlap each other to form a labyrinth structure.

This configuration can prevent liquids such as water from entering the battery unit between the first and second cover members, improving the waterproofing of the battery unit.

The battery unit of the present invention has the effect of improving the strength of the battery unit against impacts from above.

FIG. 1 is a diagram showing the general shape of a vehicle equipped with a battery unit according to an embodiment. FIG. 2 is a plan view showing a floor and a battery unit of the vehicle according to the embodiment. FIG. 3 is a cross-sectional view taken along line III-III of FIG. FIG. 4 is a cross-sectional view showing a labyrinth structure in a protective cover of a battery unit according to an embodiment. FIG. 5 is a plan view showing the battery unit according to the embodiment, with a protective cover partially removed. FIG. 6 is a cross-sectional view showing a portion including a protruding portion of a skeleton frame in a battery unit according to an embodiment. FIG. 7 is a perspective view showing a portion including a blower in the battery unit according to the embodiment. FIG. 8 is a plan view showing a portion including a blower in the battery unit according to the embodiment. FIG. 9 is a cross-sectional view showing a mounting structure of a blower in a battery unit according to an embodiment.

One embodiment will be described below. Note that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. Furthermore, the drawings may include parts with different dimensional relationships and ratios. Furthermore, in this specification, ordinal numbers are used only to distinguish between parts, members, locations, positions, directions, etc., and do not indicate order or priority.

Figure 1 is a diagram showing the general shape of a vehicle 100 in which a battery unit 1 according to an embodiment is mounted. The vehicle is an electric vehicle such as a hybrid vehicle or an electric car. The vehicle 100 has a front seat 103, a rear seat 104, and a battery unit 1 on a floor 102 of an interior 101. The battery unit 1 is installed under the front seat 103. The battery unit 1 is also referred to as a power supply unit.

A three-dimensional coordinate system is shown in each drawing. In the three-dimensional coordinate system, the front-rear direction of the vehicle 100 and the battery unit 1 is the X-axis direction, the width direction (left-right direction) is the Y-axis direction, and the up-down direction (height direction) is the Z-axis direction. The positive direction of the X-axis is the rear in the front-rear direction, and the negative direction of the X-axis is the front in the front-rear direction. The positive direction of the Y-axis is the right, and the negative direction of the Y-axis is the left. The positive direction of the axis is upward, and the negative direction of the Z-axis is downward. Furthermore, hereafter, unless otherwise specified, the front-rear direction is the front-rear direction of the vehicle 100 and the battery unit 1, the width direction is the width direction of the vehicle 100 and the battery unit 1, and the up-down direction is the up-down direction of the vehicle 100 and the battery unit 1.

Figure 2 is a plan view showing the floor 102 and battery unit 1 of the vehicle 100 according to the embodiment. As shown in Figure 2, the floor 102 is a part of the vehicle body, and has at least a left side member 5L, a right side member 5R, a front cross member 6F, and a rear cross member 6R. The floor 102 is also called a floor panel.

The left side member 5L and the right side member 5R each extend in the front-rear direction and are arranged at intervals from each other in the width direction. The front cross member 6F and the rear cross member 6R each extend in the width direction and are arranged at intervals from each other in the front-rear direction. The front cross member 6F and the rear cross member 6R are provided across the left side member 5L and the right side member 5R, respectively. In the floor 102, a plate-shaped panel portion is provided in the area surrounded by the left side member 5L, the right side member 5R, the front cross member 6F, and the rear cross member 6R, and the battery unit 1 is disposed above this panel portion.

Figure 3 is a cross-sectional view taken along line III-III of Figure 2. As shown in Figures 2 and 3, the battery unit 1 includes a case 11, a battery pack 12, a blower 13 (Figure 2), a control device 14 (Figure 2), and a waterproof tray 15 (Figure 3). The case 11 houses the battery pack 12, the blower 13, and the control device 14. The battery pack 12, the blower 13, and the control device 14 are arranged in the width direction. The blower 13 is disposed on one side of the battery pack 12 (for example, the right side), and the control device 14 is disposed on the other side of the battery pack 12 (for example, the left side). The waterproof tray 15 houses the case 11, the battery pack 12, the blower 13, and the control device 14.

The battery pack 12 is a secondary battery (battery) that supplies electricity to the motor of the vehicle 100, and is, for example, a lithium-ion battery. The battery pack 12 is charged by regenerative power or power from a charger. The blower 3 blows air to the battery pack 12 inside the protective cover 2 to cool the battery pack 12. The control device 14 controls the battery pack 12 and the blower 13. The control device 14 is, for example, a battery management system, and has a plurality of electronic components. The plurality of electronic components includes high-voltage components to which a high voltage is applied.

Each part is explained in detail below.

As shown in FIG. 3, the waterproof tray 15 is open upward. The waterproof tray 15 is fastened to the front cross member 6F and the rear cross member 6R via a number of brackets 32, for example, by bolts 27 and 28. The brackets 32 are also called waterproof tray brackets.

As shown in Figures 2 and 3, the case 11 has a lower case 21 (Figure 3) and a protective cover 22.

The lower case 21 is open upward and houses the battery pack 12, blower 13, and control device 14 inside. The lower case 21 is fixed to the floor 102. For example, the lower case 21 is fastened to the front cross member 6F and the rear cross member 6R via the bracket 32. As a result, the battery pack 12 is fastened to the front cross member 6F and the rear cross member 6R via the lower case 21 and the bracket 32. In other words, the bracket 32 fastens the battery pack 12 (lower case 21) and the waterproof tray 15 to the front cross member 6F and the rear cross member 6R.

The protective cover 22 is provided above the lower case 21 and covers the opening of the lower case 21. The protective cover 22 is provided above the battery pack 12, the blower 13, and the control device 14 and covers the battery pack 12, the blower 13, and the control device 14.

The protective cover 22 is composed of a combination of multiple members. For example, as shown in FIG. 2, the protective cover 22 has a first cover member 23, a second cover member 24, and a third cover member 25. The protective cover 22 is fixed to the front cross member 6F and the rear cross member 6R by bolts 27 to 29, etc.

The first cover member 23 is located at least above the battery pack 12 and covers the battery pack 12. The second cover member 24 is located at least above the control device 14 and covers the control device 14. The third cover member 25 is located at least above the blower 13 and covers the blower 13.

Figure 4 is a cross-sectional view showing the labyrinth structure 22a in the protective cover 22 of the battery unit 1 according to the embodiment. As shown in Figures 2 and 3, the first cover member 23 and the second cover member 24 are overlapped in the vertical direction at their overlapping portions 23a, 24a, which are parts of each other. As an example, the overlapping portion 24a of the second cover member 24 is overlapped with a gap on the upper side of the overlapping portion 23a of the first cover member 23. The overlapping portion 24a of the second cover member 24 may be overlapped with a gap on the lower side of the overlapping portion 23a of the first cover member 23. The overlapping portion 23a of the first cover member 23 and the overlapping portion 24a of the second cover member 24 may also be in contact with each other.

As shown in FIG. 4, the two overlapping portions 23a, 24a form a labyrinth structure 22a. In detail, the overlapping portion 23a of the first cover member 23 has a first portion 23aa, a second portion 23ab, and a third portion 23ac. The first portion 23aa spreads in a direction perpendicular to the up-down direction. The second portion 23ab extends from the left end (negative direction of the Y axis) of the first portion 23aa so as to move upward as it moves leftward. In other words, the second portion 23ab extends diagonally upward from the first portion 23aa to the left. The second portion 23ab is also called an inclined portion. The third portion 23ac extends leftward from the left end (negative direction of the Y axis) of the second portion 23ab.

The overlapping portion 24a of the second cover member 24 has a first portion 24aa, a second portion 24ab, and a third portion 24ac. The first portion 24aa spreads in a direction perpendicular to the up-down direction. The second portion 24ab extends from the right end of the first portion 23aa (positive direction of the Y axis) so as to move downward as it moves to the right. In other words, the second portion 24ab extends diagonally downward to the right from the first portion 24aa. The second portion 24ab is also referred to as an inclined portion. The third portion 24ac extends to the right from the right end of the second portion 24ab (positive direction of the Y axis).

The third portion 24ac of the overlapping portion 24a of the second cover member 24 is positioned above the first portion 23aa of the overlapping portion 23a of the first cover member 23, with a gap therebetween. The second portion 24ab of the overlapping portion 24a of the second cover member 24 is positioned above the second portion 23ab of the overlapping portion 23a of the first cover member 23, with a gap therebetween. The first portion 24aa of the overlapping portion 24a of the second cover member 24 is positioned above the third portion 23ac of the overlapping portion 23a of the first cover member 23, with a gap therebetween.

The labyrinth structure 22a configured as described above prevents liquids such as water from entering the inside of the protective cover 22 from between the overlapping portion 23a of the first cover member 23 and the overlapping portion 24a of the second cover member 24. The gap between the overlapping portion 23a of the first cover member 23 and the overlapping portion 24a of the second cover member 24 may be sealed with a sealing member.

As shown in FIG. 2, a plurality of (two in one example) skeletal frames 26A, 26B are fixed to the protective cover 22. The skeletal frame 26A is fixed to the first cover member 23, and the skeletal frame 26B is fixed to the second cover member 24. Hereinafter, the skeletal frame 26 will be used as a general term for the plurality of skeletal frames 26A, 26B. Below, an example will be described in which one skeletal frame 26 is provided for each of the first cover member 23 and the second cover member 24, but the number of skeletal frames 26 is not limited to this. For example, a plurality of skeletal frames 26 may be provided for each of the first cover member 23 and the second cover member 24.

Figure 5 is a plan view showing the battery unit 1 according to the embodiment, with a portion of the protective cover 22 removed. Specifically, Figure 5 shows the first cover member 23 and the second cover member 24 of the protective cover 22 removed.

As shown in FIG. 5, the multiple skeletal frames 26 each extend in the front-to-rear direction and are arranged at intervals from one another in the width direction. Each skeletal frame 26 is provided across the front cross member 6F and the rear cross member 6R and is fixed to the front cross member 6F and the rear cross member 6R. In other words, each skeletal frame 26 bridges the front cross member 6F and the rear cross member 6R.

The skeletal frame 26 is a plate member whose longitudinal direction is the front-to-rear direction. The skeletal frame 26 is made, for example, by processing a hat-shaped member, and at least a portion of the cross section is hat-shaped. The skeletal frame 26 is made, for example, from a metal material.

The skeletal frame 26 has a front end 26a, a rear end 26b opposite the front end 26a, a left end 26c, and a right end 26d opposite the left end 26c.

2 and 3, the front end 26a and the rear end 26b of the skeletal frame 26 are fastened to the front cross member 6F and the rear cross member 6R by bolts 27. The bolts 27 are coupled with nuts (not shown) to fasten the skeletal frame 26 to the front cross member 6F and the rear cross member 6R. More specifically, as shown in FIG. 3, the front end 26a and the rear end 26b of the skeletal frame 26 overlap the bracket 32 and are fastened to the front cross member 6F and the rear cross member 6R together with the bracket 32 by the bolts 27. That is, the skeletal frame 26 is fastened together with the bracket 32 to the front cross member 6F and the rear cross member 6R. Here, the bracket 32 that fastens the skeletal frame 26B to the front cross member 6F and the rear cross member 6R is fastened to the front cross member 6F and the rear cross member 6R by bolts 28 (FIG. 2) in addition to the bolts 27. However, the bolts 28 do not fasten the skeletal frame 26B to the front cross member 6F and the rear cross member 6R. That is, the bolts 28 fasten the waterproof tray 15 to the front cross member 6F and the rear cross member 6R via the brackets 32, but do not fasten the skeletal frame 26B. Therefore, when performing maintenance on the control device 14, it is possible to remove the bolts 27 and remove only the second cover member 24 to perform maintenance. At this time, because the bolts 28 fasten the waterproof tray 15 to the front cross member 6F and the rear cross member 6R, there is no risk of the waterproof tray 15 (battery pack 12) coming off the front cross member 6F and the rear cross member 6R.

5, the left end 26c and the right end 26d of the skeletal frame 26 are provided with uneven portions 26e. The uneven portions 26e have a plurality of convex portions 26ea arranged at intervals in the front-rear direction. Each of the convex portions 26ea is fixed to the protective cover 22. Specifically, each of the convex portions 26ea is welded to the protective cover 22. In detail, the convex portion 26ea of the skeletal frame 26A is welded to the first cover member 23, and the convex portion 26ea of the skeletal frame 26B is welded to the second cover member 24. The welding between the skeletal frame 26 and the protective cover 22 is, for example, spot welding, but is not limited to this. In FIG. 5, the welded points 26g on the skeletal frame 26 are indicated by black circles. Note that the welded points 26g between the skeletal frame 26 and the protective cover 22 are not limited to the above.

Figure 6 is a cross-sectional view showing a portion including the protrusion 26i of the skeletal frame 26A in the battery unit 1 according to the embodiment. As shown in Figures 5 and 6, the skeletal frame 26A is provided with the protrusion 26i. A plurality of protrusions 26i (two, for example) are provided on the left end 26c of the skeletal frame 26A. The plurality of protrusions 26i are provided at intervals in the front-rear direction. The plurality of protrusions 26i protrude leftward from the left end 26c, i.e., on the opposite side to the blower 13. The protrusions 26i are integrally formed with the skeletal frame 26A. The protrusions 26i may be provided as separate members from the skeletal frame 26A and fixed to the skeletal frame 26A by fastening or the like.

6, the protrusion 26i is located on the upper side of the battery pack 12. The protrusion 26i has a first portion 26ia, a second portion 26ib, and a third portion 26ic. The first portion 26ia extends in a direction perpendicular to the up-down direction. The second portion 26ib extends downward as it moves leftward from the left end (negative direction of the Y axis) of the first portion 26iaa. In other words, the second portion 26ib extends diagonally downward to the left from the first portion 26ia. The second portion 26ib is also referred to as an inclined portion. The third portion 26ic extends leftward from the left end (negative direction of the Y axis) of the second portion 26ib.

When the battery pack 12 moves upward toward the skeletal frame 26A for some reason, the upper part of the battery pack 12 comes into contact with the third portion 26ic of the protrusion 26i configured as described above. In this state, the protrusion 26i limits the upward movement of the battery pack 12.

5, the skeletal frame 26A is provided with a fixing portion 26h. The blower 13 is fixed to the fixing portion 26h. In other words, the blower 13 is attached to the fixing portion 26h. The fixing portion 26h is also referred to as a blower attachment portion. A plurality of fixing portions 26h (two, for example) are provided at the right end portion 26d of the skeletal frame 26A. The plurality of fixing portions 26h are provided at intervals in the front-rear direction. The plurality of fixing portions 26h protrude from the left end portion 26c to the right, that is, on the opposite side to the battery pack 12. The fixing portion 26h is integrally formed with the skeletal frame 26A. The fixing portion 26h may be provided as a separate member from the skeletal frame 26A and fixed to the skeletal frame 26A by fastening or the like. The shape of the fixing portion 26h will be described in detail later.

The battery pack 12 shown in FIG. 3 has multiple battery cells 31 and a bracket 32. The multiple battery cells 31 store electricity to be supplied to the motor of the vehicle 100. The bracket 32 supports the multiple battery cells 31. The bracket 32, together with the skeleton frame 26, is fastened to the front cross member 6F and the rear cross member 6R by bolts 27.

Figure 7 is a perspective view showing a portion of the battery unit 1 according to the embodiment that includes the blower 13. Figure 8 is a plan view showing a portion of the battery unit 1 according to the embodiment that includes the blower 13.

As shown in Figures 7 and 8, the blower 13 has a case 41. The case 41 houses an impeller and a motor that drives the impeller to rotate. The blower 13 rotates the impeller with the motor, sucking in air from the air intake of the case 41 and blowing the sucked air from the air outlet of the case 41 onto the battery pack 12, thereby cooling the battery pack 12 with the air flow. In other words, the blower 13 generates an air flow that cools the battery pack 12.

The case 41 has a case body 41a that houses the impeller and the motor, and multiple fixing parts 41b, 41c that protrude from the case body 41a.

Next, the fixing structure of the blower 13 will be described. The blower 13 is fixed to the skeleton frame 26A and the lower case 21. In detail, the fixing portion 41b of the case 41 is fastened to the fixing portion 26h of the skeleton frame 26A by a bolt 42, and the fixing portion 41c is fastened to the fixing portion 21b of the lower case 21 by a bolt 42.

Figure 9 is a cross-sectional view showing the mounting structure of the blower 13 in the battery unit 1 according to the embodiment. As shown in Figure 9, the fixing portion 41b is placed on top of the fixing portion 21h of the skeletal frame 26A and fastened to the fixing portion 21h of the skeletal frame 26A by a bolt 42. The bolt 42 is coupled with a nut 43 to fix the fixing portion 41b of the blower 13 to the fixing portion 26h of the skeletal frame 26A.

Here, the fixing portion 26h of the skeletal frame 26A has a first portion 26ha, a second portion 26hb, and a third portion 26hc. The first portion 26ha extends in a direction perpendicular to the up-down direction. The second portion 26hb extends from the right end of the first portion 26aa (positive direction of the Y axis) so as to move downward as it moves to the right. In other words, the second portion 26hb extends diagonally downward to the right from the first portion 26aa. The second portion 26hb is also referred to as an inclined portion. The third portion 26hc extends to the right from the right end of the second portion 26hab (positive direction of the Y axis). The fixing portion 41b of the blower 13 is fastened to this third portion 26hc.

As shown in FIG. 8, the fixing portion 21b of the lower case 21 protrudes from the inner surface of the lower case 21. A female thread is provided on the fixing portion 21b. The fixing portion 41c of the case 41 is placed on the upper side of the fixing portion 21b of the lower case 21 and is fastened to the fixing portion 21b by a bolt 42. The bolt 42 engages with the female thread and fixes the fixing portion 41c of the blower 13 to the fixing portion 21b of the lower case 21.

The blower 13 configured as described above can also be said to be fixed such that at least a portion of the case body 41a is suspended from the skeletal frame 26A and the lower case 21 via the fixing parts 41b and 41c.

As described above, the battery unit 1 of this embodiment is disposed between the right side member 5R and the left side member 5L (two side members) provided on the vehicle 100 and the front cross member 6F and the rear cross member 6R (two cross members) provided on the vehicle 100. The battery unit 1 includes a battery pack 12, a protective cover 22, and a skeletal frame 26. The battery pack 12 supplies electricity to the vehicle 100. The protective cover 22 covers the battery pack 12 on the upper side thereof. The skeletal frame 26 is located below the protective cover 22, and is welded to the protective cover 22 across the front cross member 6F and the rear cross member 6R, and is fastened to the two front cross members 6F and the rear cross member 6R.

With this configuration, the skeletal frame 26 is welded to the protective cover 22 and fastened to the front cross member 6F and the rear cross member 6R, improving the strength (resistance) of the battery unit 1 against impacts from above. Therefore, even if an object inside the vehicle falls onto the battery unit 1, it is possible to prevent the battery pack 12 and the control device 14 (high-voltage components, etc.) in the battery unit 1 from receiving an impact. In addition, in the event of a longitudinal collision of the vehicle 100, the skeletal frame 26 can prevent the gap between the front cross member 6F and the rear cross member 6R on the floor 102 from being crushed and narrowed. Therefore, with the above configuration, the safety of the battery unit 1 can be improved.

The battery unit 1 is also arranged, for example, in a direction intersecting the vertical direction with the battery pack 12 and includes a control device 14 that controls the battery pack 12. The protective cover 22 has a first cover member 23 that covers the battery pack 12 above the battery pack 12, and a second cover member 24 that covers the control device 14 above the control device 14. Each of the first cover member 23 and the second cover member 24 is provided with at least one skeletal frame 26.

With this configuration, the protective cover 22 is divided into at least a first cover member 23 that covers the battery pack 12 and a second cover member 24 that covers the control device 14, so that when repairing the control device 14, only the second cover member 24 can be removed. This improves the ease of working on the battery unit 1.

In addition, in the battery unit 1, for example, the overlapping portion 23a (part) of the first cover member 23 and the overlapping portion 24a (part) of the second cover member 24 overlap each other to form a labyrinth structure 22a.

This configuration can prevent liquids such as water from entering the battery unit 1 between the first cover member 23 and the second cover member 24, thereby improving the waterproofing of the battery unit 1.

Although an embodiment of the present invention has been described, the above embodiment is presented as an example and is not intended to limit the scope of the invention. The above embodiment can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the gist of the invention. The above embodiment and its variations are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1...battery unit, 5L...left side member (side member), 5R...right side member (side member), 6F...front cross member (cross member), 6R...rear cross member (cross member), 12...battery pack, 13...blower, 14...control device, 21...lower case, 22...protective cover, 22a...labyrinth structure, 23...first cover member, 23a...overlapping portion (part), 24...second cover member, 24a...overlapping portion (part), 26, 26A, 26B...skeletal frame, 26c...left end (other end), 26d...right end (one end), 26i...protruding portion, 100...vehicle.

Claims (3)

A battery unit disposed between two side members provided on a vehicle and two cross members provided on the vehicle,
A battery pack that supplies electricity to the vehicle;
a protective cover for covering the battery pack from above the battery pack;
a framework frame located below the protective cover, spanning the two cross members, welded to the protective cover, and fastened to the two cross members;
A battery unit equipped with a control device arranged in a direction intersecting the up-down direction with the battery pack and controlling the battery pack;
The protective cover is
a first cover member that covers the battery pack from an upper side of the battery pack;
A second cover member that covers the control device from above the control device;
having
At least one of the skeleton frames is provided on each of the first cover member and the second cover member.
The battery unit according to claim 1 . A portion of the first cover member and a portion of the second cover member overlap each other to form a labyrinth structure.
The battery unit according to claim 2 .

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