Battery pack

Abstract

This disclosure aims to provide a battery pack in which manufacturing costs are reduced compared to cases where the frame is formed from extruded material, and cooling efficiency is improved compared to cases where a casing is used to waterproof the underside of the frame and the cooler and battery module are in indirect contact. [Solution] The battery pack 102 comprises a frame 110 made of sheet metal and frame-shaped on all four sides, a battery module 180 arranged inside the frame 110, a cover member 182 fixed to the upper end of the frame 110 and covering the upper surface of the battery module 180, and a cooler 190 fixed to the lower end of the frame 110 and covering the lower surface of the battery module 180 and cooling the battery module 180 by directly contacting it.

Description

Technical Field

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

Background Art

[0002] For example, Patent Document 1 discloses an attachment structure of an electric connector for an electric vehicle battery pack, which includes a box-shaped tray that houses a battery and has an open upper surface, a box-shaped cover that has an open lower surface and is joined to the tray on a horizontal plane, and an electric connector to which an electric cable is connected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology of Patent Document 1, since waterproofing is performed using a box-shaped tray with an open upper surface, it is necessary to cool the battery module housed inside the tray with a cooler through the tray. Therefore, since the cooler and the battery module are indirectly in contact, the cooling efficiency is reduced.

[0005] Further, when the frame for housing the battery module is formed of an extruded material with a closed structure, although the strength of the frame is ensured, the cost of forming the frame increases.

[0006] An object of the present disclosure is to provide a battery pack with reduced manufacturing costs compared to the case where the frame is formed of an extruded material, and improved cooling efficiency compared to the case where a housing is used to waterproof the lower surface of the frame and the cooler and the battery module are indirectly in contact.

Means for Solving the Problems

[0007] The battery pack of the first embodiment comprises a frame made of sheet metal and having a frame-like shape on all four sides; a battery module disposed inside the area enclosed by the frame; a cover member fixed to the upper end of the frame and covering the upper surface of the battery module; and a cooler fixed to the lower end of the frame, covering the lower surface of the battery module and cooling the battery module by directly contacting it.

[0008] In this battery pack, the frame is formed from sheet metal. The top surface of the battery pack is covered by a lid member, and the bottom surface of the battery pack is covered by a cooler that is in direct contact with the battery module. Therefore, this embodiment of the battery pack allows for a reduction in manufacturing costs compared to cases where the frame is formed from extruded material. Furthermore, in this embodiment of the battery pack, since the battery module and the cooler are in direct contact, the cooling efficiency is improved compared to cases where a casing is used to waterproof the bottom surface of the frame and the cooler and battery module are indirectly in contact.

[0009] The battery pack of the second embodiment is the battery pack of the first embodiment, wherein the frame has plate-shaped upper plate-shaped portions at the upper ends of each of the four sides and plate-shaped lower plate-shaped portions at the lower ends of each of the four sides, the lid member is fixed to the upper plate-shaped portions with other waterproofing material in between, and the cooler is fixed to the lower plate-shaped portions with waterproofing material in between.

[0010] This battery pack has a frame with an upper plate-like portion and a lower plate-like portion. The lid member is fixed to the upper plate-like portion with a waterproofing material in between, and the cooler is fixed to the lower plate-like portion with another waterproofing material in between. Therefore, according to this embodiment of the battery pack, waterproofing of the battery module is ensured.

[0011] The third embodiment of the battery pack is the battery pack described in the second embodiment, wherein the frame has frame pieces on each of its four sides, each having a wall surface connecting the upper plate-like portion and the lower plate-like portion, and the plurality of frame pieces are integrated in a state in which the frame pieces on adjacent sides overlap the upper plate-like portion, the lower plate-like portion and the wall surface portion.

[0012] In this battery pack, the frame is constructed with frame pieces on each of its four sides. Each frame piece is then integrated with the adjacent frame piece by overlapping them. Therefore, this embodiment of the battery pack allows for a reduction in manufacturing costs compared to a case where the frame is made from a single sheet of metal.

[0013] The fourth embodiment of the battery pack is the battery pack described in the third embodiment, wherein at least one of the frame pieces is joined to a second frame piece having a second wall portion facing the wall portion, a second upper plate portion which is plate-shaped and overlaps the upper plate portion, and a second lower plate portion which is plate-shaped and overlaps the lower plate portion, so that the cross section viewed from the direction in which the frame piece extends is enclosed.

[0014] This battery pack has a closed structure because at least one frame piece is joined to a second frame piece. Therefore, the strength of this battery pack is improved compared to a case where all frame pieces have an open structure.

[0015] The fifth embodiment of the battery pack is the battery pack described in the third or fourth embodiment, wherein at least one of the frame pieces is bent such that both ends of the frame piece in the direction in which the wall portion extends are bent such that the inside of the frame is on the inside of the bend.

[0016] In this battery pack, at least one frame piece has both ends of its wall surface bent such that the inside of the frame faces the inside of the bend. Therefore, the strength of this battery pack is improved compared to a case where all frame pieces are flat in the direction in which their respective wall surfaces extend. [Effects of the Invention]

[0017] According to the present disclosure, compared with the case where the frame is formed of an extruded material, the manufacturing cost is reduced, and compared with the case where a housing is used to waterproof the lower surface of the frame and the cooler and the battery module are in indirect contact, a battery pack with improved cooling efficiency is provided.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram for explaining how the battery pack according to the present disclosure is used in a vehicle. [Figure 2] It is a diagram for explaining the battery pack according to the present disclosure, and is a perspective view of the battery pack. [Figure 3] It is a diagram for explaining the battery pack according to the present disclosure, and is a perspective view showing the internal structure of the battery pack. [Figure 4] It is a perspective view showing the cooler included in the battery pack according to the present disclosure. [Figure 5] It is a perspective view showing the lid member included in the battery pack according to the present disclosure. [Figure 6] It is a perspective view showing the frame included in the battery pack according to the present disclosure. [Figure 7] It is a perspective view showing the front frame piece included in the frame according to the present disclosure. [Figure 8] It is a perspective view showing the rear frame piece included in the frame according to the present disclosure. [Figure 9] It is a perspective view showing the left frame piece included in the frame according to the present disclosure. [Figure 10] It is a perspective view showing the second frame piece included in the left frame according to the present disclosure. [Figure 11] In the frame according to the present disclosure, it is a perspective view showing a state in which the rear frame piece and the left frame piece are joined while being overlapped. [Figure 12] It is a cross-sectional view taken from the 2A-2A direction in FIG. 2, and is a diagram showing a state in which the left frame according to the present disclosure has a closed structure by the first frame piece and the second frame piece.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, an example of an embodiment of this disclosure will be described with reference to the drawings. In each drawing, the same or equivalent components and parts are given the same reference numerals. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0020] Furthermore, the arrow UP shown in each figure is in the vertical direction and indicates the upward direction of the vehicle 100, the arrow RH is in the horizontal direction and indicates the right direction in the width direction of the vehicle 100, the arrow LH is in the horizontal direction and indicates the left direction in the width direction of the vehicle 100, and the arrow FR is in the horizontal direction and indicates the forward direction of the vehicle 100. For the purposes of this description, the vertical direction, width direction and front-rear direction of the battery pack 102 all coincide with the vertical direction, width direction and front-rear direction of the vehicle 100.

[0021] (composition) Figure 1 shows a vehicle 100 equipped with a battery pack 102 according to this disclosure. The vehicle 100 is a so-called electric vehicle that uses electricity as its energy source and runs by drawing electricity from the battery pack 102. The battery pack 102 is located under the floor of the cabin in the vehicle 100. More specifically, the battery pack 102 is mounted to the vehicle 100 from below in a space provided under the floor. In other words, the battery pack 102 is located under the cabin floor in a space partitioned from the cabin.

[0022] Figure 2 shows a perspective view of the battery pack 102 according to this disclosure. Figure 3 shows the internal structure of the battery pack 102 according to this disclosure. As shown in Figures 2 and 3, the battery pack 102 according to this disclosure is, for example, a roughly rectangular parallelepiped with the longitudinal direction of the vehicle 100 as its longitudinal direction. As shown in Figures 2 and 3, the battery pack 102 according to this disclosure comprises a cooler 190, a battery module 180, a lid member 182, a frame 110, a beam member 118, and a gasket 178.

[0023] As shown in Figures 2 and 3, the battery module 180 is a component housed inside the battery pack 102 that is capable of storing and releasing electricity. More specifically, as shown in Figure 3, the battery modules 180 are arranged in a front-to-back direction inside the battery pack 102. Any type of battery module 180 can be used, but a lithium-ion battery is used as an example.

[0024] In this embodiment, the battery modules 180 are electrically connected in parallel by electrical wiring (not shown). Electrical terminals for inputting and outputting electricity from the battery modules 180 are also omitted from the illustration.

[0025] The cooler 190 is a component located on the underside of the battery pack 102, as shown in Figures 2 and 3. More specifically, the cooler 190 has a roughly rectangular shape, with dimensions similar to those of the battery pack 102, as shown in Figure 4.

[0026] Furthermore, as shown in Figure 4, the cooler 190 has a flow path 192 formed inside through which cooling water flows. As shown in Figure 4, the flow path 192 is connected to an inlet 194I and an outlet 194O located on the front side of the cooler 190. In other words, cooling water flows into the cooler 190 from the inlet 194I, passes through the flow path 192, and flows out from the outlet 194O.

[0027] Furthermore, the upper surface of the cooler 190 is formed of a material with high thermal conductivity, such as aluminum, as an example. Therefore, the upper surface of the cooler 190 is cooled by the cooling water flowing through the channel 192.

[0028] Furthermore, as shown in Figure 4, the cooler 190 has multiple through holes 196 on the edges of its four sides (front, back, left, and right). These through holes 196 are, for example, arranged at equal intervals along the edges of the four sides (front, back, left, and right) in the direction in which each side extends. The top surface of the cooler 190 is in contact with the lower plate-like portion 124 of the frame 110, which will be described later.

[0029] The lid member 182 is a component positioned on the upper side of the battery pack 102, as shown in Figure 5. More specifically, the lid member 182 is roughly rectangular in shape, with dimensions equivalent to those of the battery pack 102, as shown in Figure 2.

[0030] Furthermore, as shown in Figure 5, the lid member 182 has multiple through holes 186 on the edges of its four sides (front, back, left, and right). These through holes 186 are, for example, arranged at equal intervals along the edges of the four sides (front, back, left, and right) in the direction in which each side extends. The bottom surface of the lid member 182 is in contact with the upper plate-like portion 122 of the frame 110, which will be described later.

[0031] The frame 110 is a component that houses the battery module 180, as shown in Figure 3. The frame 110 has multiple frame pieces that each form one of the four sides, creating a roughly rectangular frame, as shown in Figures 3 and 6. In this embodiment, the frame pieces are the front frame piece 120, the rear frame piece 130, the left frame piece 140L, and the right frame piece 140R. The frame 110 is roughly rectangular in shape, with dimensions equivalent to those of the battery pack 102 when viewed from above.

[0032] As shown in Figures 6 and 7, the front frame piece 120 extends in the left-right direction and is a member that forms the edge of the front portion of the frame 110. The front frame piece 120 has a wall surface portion 126 that extends in the vertical direction, an upper plate-like portion 122 that connects to the upper end of the wall surface portion 126 and extends toward the front, and a lower plate-like portion 124 that connects to the lower end of the wall surface portion 126 and extends toward the front.

[0033] The wall portion 126 is the front wall portion of the frame 110. A hole 129 is drilled through the wall portion 126 in the thickness direction, and a connector (not shown) is provided in the hole 129. The connector (not shown) is electrically connected to a battery module 180 housed inside the frame 110. The connector (not shown) is in contact with the wall portion 126 via a waterproofing material, and is structured to prevent liquid from entering the inside of the frame 110 through the hole 129 in the wall portion 126.

[0034] The upper plate-like portion 122 is the upper surface portion at the front of the frame 110. Holes 128 are drilled in the upper plate-like portion 122, arranged in the left-right direction. A weld nut 108 is welded to the lower side (i.e., the opposite side of the upper surface) of each hole 128. The spacing between these holes 128 is the same as the spacing between the through holes 186 drilled in the front edge of the cover member 182 described above. The upper plate-like portion 122 also sandwiches the gasket 178 together with the cover member 182.

[0035] The lower plate-like portion 124 is the lower surface portion at the front of the frame 110. Holes 128 are drilled in the lower plate-like portion 124, arranged in the left-right direction. A weld nut 108 is welded to the upper side (i.e., the opposite side of the lower surface) of each hole 128. The spacing between these holes 128 is the same as the spacing between the through holes 196 drilled in the front edge of the cooler 190, which will be described later.

[0036] In other words, the front frame piece 120 in this embodiment is a member with a substantially U-shaped cross-section. The front frame piece 120 is made of sheet metal. The material of the sheet metal is set as appropriate, but as an example, galvanized steel sheet is used. The galvanized steel sheet may be made by electro-galvanizing or by hot-dip galvanizing. Furthermore, the zinc plated on the steel sheet may be a zinc-aluminum-magnesium alloy. Moreover, it is not limited to galvanized steel sheet, and a steel sheet with a painted surface may be used.

[0037] In this embodiment, both ends of the front frame piece 120 in the left-right direction are bent toward the rear. More specifically, as shown in Figure 6, both ends of the front frame piece 120 in the left-right direction are bent such that the surface that faces the inside of the frame 110 faces the inside of the bend.

[0038] As shown in Figures 6 and 8, the rear frame piece 130 extends in the left-right direction and is a member that forms the edge of the rear portion of the frame 110. The rear frame piece 130 has a wall surface portion 136 that extends in the vertical direction, an upper plate-like portion 132 that connects to the upper end of the wall surface portion 136 and extends toward the rear, and a lower plate-like portion 134 that connects to the lower end of the wall surface portion 136 and extends toward the rear. Also, as shown in Figures 6 and 8, both ends of the rear frame piece 130 in the left-right direction are bent toward the rear. More specifically, as shown in Figure 6, both ends of the rear frame piece 130 in the left-right direction are bent so that the surface that is on the inside of the frame 110 is on the inside of the bend.

[0039] In other words, each component of the rear frame piece 130 (upper plate-like portion 132, wall portion 136, lower plate-like portion 134, and hole 139) corresponds functionally to each component with the same name in the front frame piece 120 (upper plate-like portion 122, wall portion 126, lower plate-like portion 124, and hole 129). As shown in Figures 7 and 8, the shapes of the wall portion 126 and wall portion 136, the upper plate-like portion 122 and upper plate-like portion 132, and the hole 129 and hole 139 are different, but their functions are equivalent. Also, although hidden in Figures 6 and 8, weld nuts 108 are welded to the back side of the holes 138 drilled in the upper plate-like portion 132 and lower plate-like portion 134, similar to the holes 128 drilled in the upper plate-like portion 122 and lower plate-like portion 124.

[0040] Furthermore, the rear frame piece 130 in this embodiment is a member with a substantially U-shaped cross-section. The rear frame piece 130 is made of sheet metal. The material of the sheet metal is set as appropriate, but as an example, the same material as the front frame piece 120 is used.

[0041] The left frame piece 140L extends in the front-rear direction and forms the left side of the frame 110, as shown in Figures 6 and 9. The left frame piece 140L has a first frame piece 150L and a second frame piece 160L.

[0042] As shown in Figure 9, the first frame piece 150L has a wall portion 156L extending in the vertical direction, a first upper plate-like portion 152L connected to the upper end of the wall portion 156L and extending toward the left, and a first lower plate-like portion 154L connected to the lower end of the wall portion 156L and extending toward the left.

[0043] The wall portion 156L is the left-side wall portion of the frame 110. More specifically, as shown in Figure 6, the wall portion 156L is the portion that demarcates the inside and outside of the frame 110 on its left side.

[0044] The first upper plate-like portion 152L is the upper surface portion on the left side of the frame 110. Also, in Figure 12, which will be described later, the first upper plate-like portion 152L is the portion that sandwiches the gasket 178 together with the cover member 182.

[0045] The first lower plate-like portion 154L is the lower surface portion on the left side of the frame 110. Holes are drilled in the first lower plate-like portion 154L, arranged in the front-to-back direction. A weld nut 108 is welded to the upper side (i.e., the opposite side of the lower surface) of each hole. The spacing between these holes is the same as the spacing between the holes 128 drilled on the left edge of the cooler 190. Furthermore, the first lower plate-like portion 154L is the portion that sandwiches the gasket 178 together with the cooler 190 in Figure 12, which will be described later.

[0046] In other words, the first frame piece 150L in this embodiment is a member with a substantially U-shaped cross-section. The first frame piece 150L is made of sheet metal. The material of the sheet metal is set as appropriate, but as an example, the same material as the front frame piece 120 is used.

[0047] As shown in Figure 9, the second frame piece 160L has a second wall portion 166L extending in the vertical direction, a second upper plate-like portion 162L connected to the upper end of the second wall portion 166L and extending toward the right, and a second lower plate-like portion 164L connected to the lower end of the second wall portion 166L and extending toward the right.

[0048] The second wall section 166L is the left-side wall section of the frame 110.

[0049] The second upper plate-like portion 162L is the upper surface portion on the left side of the frame 110. Through holes 168L are drilled in the second upper plate-like portion 162L, arranged in the front-to-back direction. A weld nut 108 is welded to the lower side (i.e., the opposite side of the upper surface) of each through hole 168L. The spacing between these through holes 168L is the same as the spacing between the through holes 186 drilled in the left edge of the cover member 182 described above.

[0050] The second lower plate-like portion 164L is the lower surface portion on the left side of the frame 110. Holes are drilled in the second lower plate-like portion 164L, arranged in the front-to-back direction. A weld nut 108 is welded to the upper side (i.e., the opposite side of the lower surface) of each hole. The spacing between these holes is equivalent to the spacing between the through holes 196 drilled in the left edge of the cooler 190.

[0051] In other words, the second frame piece 160L in this embodiment is a member with a substantially U-shaped cross-section. The second frame piece 160L is made of sheet metal. The material of the sheet metal is set as appropriate, but as an example, the same material as the front frame piece 120 is used.

[0052] Furthermore, the first frame piece 150L and the second frame piece 160L are welded together at the first upper plate-like portion 152L and the second upper plate-like portion 162L. Also, the first frame piece 150L and the second frame piece 160L are welded together at the first lower plate-like portion 154L and the second lower plate-like portion 164L. More specifically, as shown in Figure 12 described later, the first frame piece 150L is overlapped so that the second upper plate-like portion 162L is above the first upper plate-like portion 152L, and the overlapped portion is welded. Also, the first frame piece 150L is overlapped so that the first lower plate-like portion 154L is below the second lower plate-like portion 164L, and the overlapped portion is welded.

[0053] Therefore, as shown in Figure 12, the first frame piece 150L has a so-called closed structure, in which the cross-section is enclosed in a roughly rectangular shape when viewed from the front-to-back direction (i.e., the direction in which the first frame piece 150L extends).

[0054] The right frame piece 140R is a member that forms the right side of the frame 110. Like the left frame piece 140L, the right frame piece 140R comprises a first frame piece 150R and a second frame piece 160R. The right frame piece 140R is symmetrical with respect to the left frame piece 140L with respect to the front-rear axis. That is, the first frame piece 150R of the right frame piece 140R is symmetrical with respect to the first frame piece 150L of the left frame piece 140L, and the second frame piece 160R of the right frame piece 140R is symmetrical with respect to the second frame piece 160L of the left frame piece 140L.

[0055] In the following explanation, when the first frame piece 150R of the right frame piece 140R and the first frame piece 150L of the left frame piece 140L are not distinguished, they will simply be referred to as "first frame piece 150," and the trailing symbol will be omitted. Similarly, for the first upper plate-like part 152R and first upper plate-like part 152L, the second upper plate-like part 162R and second upper plate-like part 162L, the first lower plate-like part 154R and first lower plate-like part 154L, the second lower plate-like part 164R and second lower plate-like part 164L, the wall surface part 156R and wall surface part 156L, and the second wall surface part 166R and second wall surface part 166L, when the left and right are not distinguished, the trailing symbol will be omitted. Similarly, for the protruding parts 142R and protruding parts 142L, which will be described later, when the left and right are not distinguished, the trailing symbol will be omitted.

[0056] In this embodiment, as shown in Figure 6, the front frame piece 120, the rear frame piece 130, the left frame piece 140L, and the right frame piece 140R are welded together to form the four sides of a rectangle, thereby constructing the frame 110.

[0057] More specifically, as shown in Figure 11, at the front end of the left frame piece 140L, the upper plate-like portion 122 and the upper plate-like portion 152 are overlapped and welded together. The lower plate-like portion 124 and the lower plate-like portion 154 are overlapped and welded together. The wall portion 126 and the wall portion 156 are overlapped and welded together.

[0058] Furthermore, as shown in Figure 11, a waterproofing agent 119 is applied to the boundary between the left frame piece 140L and the front frame piece 120. More specifically, a waterproofing agent 119, such as modified silicone resin, is applied to the step created at the boundary between the left frame piece 140L and the front frame piece 120. This prevents liquids such as water from entering the frame 110 through this step.

[0059] In this embodiment, as shown in Figure 11, the front frame piece 120 is welded so that it is inside the frame 110 more than the first frame piece 150L of the left frame piece 140L. However, it is not limited to this, and the first frame piece 150 may be welded so that it is inside the frame 110 more than the front frame piece 120 (i.e., the front frame piece 120 is inserted into the closed structure of the left frame piece 140L).

[0060] Furthermore, as described above and shown in Figure 6, the front frame piece 120 is bent so that its left and right ends are on the inside of the bend. Therefore, the upper plate-like portion 122, wall portion 126, and lower plate-like portion 124 of the front frame piece 120 are joined to the rear of the front ends of the upper plate-like portion 152, wall portion 156, and lower plate-like portion 154 of the left frame piece 140L, respectively. In other words, as shown in Figure 6, the front end of the left frame piece 140L is joined to coincide with the front end of the front frame piece 120. As shown in Figure 6, the portion of the left frame piece 140L in front of the joint with the front frame piece 120 will be referred to as the protruding portion 142L in the following description. In other words, the protruding portion 142L is the area from the front end of the first upper plate-like portion 152L, the second upper plate-like portion 162L, the wall portion 156L, the second wall portion 166L, the first upper plate-like portion 152L, and the second upper plate-like portion 162L to the joint portion with the front frame piece 120.

[0061] Furthermore, at the rear end of the left frame piece 140L, the left frame piece 140L and the rear frame piece 130 are similarly welded. Specifically, the upper plate-like portion 132 and the first upper plate-like portion 152L are overlapped and the overlapped portion is welded. Similarly, the lower plate-like portion 134 and the first lower plate-like portion 154L are overlapped and the overlapped portion is welded. Then, the wall portion 136 and the wall portion 156L are overlapped and the overlapped portion is welded. Finally, the waterproofing agent 119 is similarly applied to the boundary between the left frame piece 140L and the rear frame piece 130.

[0062] As described above and shown in Figure 6, the rear frame piece 130 is bent so that its left and right ends are on the inside of the bend. Similar to the protrusion 142L, as shown in Figure 6, the portion of the left frame piece 140L behind the joint with the rear frame piece 130 will be referred to as the protrusion 144L in the following description.

[0063] In addition to the explanation of how the front frame piece 120 and the left frame piece 140L, and the rear frame piece 130 and the left frame piece 140L are joined, the right frame piece 140R is also welded in the same manner and coated with waterproofing agent 119.

[0064] As a result, as shown in Figures 3 and 6, a frame 110 is formed that is approximately rectangular in shape and has dimensions equivalent to those of the battery pack 102. Also, as shown in Figures 3 and 6, the front frame piece 120, the rear frame piece 130, the left frame piece 140L, and the right frame piece 140R form a series of upper plate-like portions 112 on the frame 110. Similarly, the front frame piece 120, the rear frame piece 130, the left frame piece 140L, and the right frame piece 140R form a series of lower plate-like portions 114 on the frame 110. Similarly, the front frame piece 120, the rear frame piece 130, the left frame piece 140L, and the right frame piece 140R form a series of wall surfaces 116 on the frame 110.

[0065] Any welding method may be used for each part of the frame 110. Examples of welding methods include projection welding, spot welding, and laser welding.

[0066] The beam member 118 is a member positioned inside the frame 110. The beam member 118 reinforces the frame 110 and, like the frame 110, supports the load of the battery module 180.

[0067] The beam member 118 is formed of sheet metal, for example, similar to the frame 110. The beam member 118 is joined so as to span the second frame piece 160L of the left frame piece 140L and the second frame piece 160R of the right frame piece 140R. The beam member 118 is welded to the left frame piece 140L and the right frame piece 140R, respectively, similar to the frame pieces.

[0068] As shown in Figure 3, the gasket 178 is a component sandwiched between the frame 110 and the lid member 182. More specifically, as shown in Figure 3, the gasket 178 is an endless, annular component and is positioned on the upper surface of the upper plate-like portion 112 of the frame 110. Also, as shown in Figure 2, the gasket 178 fills the gap between the frame 110 and the lid member 182 when the frame 110 and the lid member 182 are joined together. Any material can be used as the gasket 178, but a rubber material with a round cross-section, such as an O-ring, is used. The gasket 178 is an example of a "waterproofing material" in this disclosure.

[0069] Furthermore, as shown in Figure 3, the gasket 178 is a component sandwiched between the frame 110 and the cooler 190. More specifically, as shown in Figure 3, the gasket 178 is an endless, annular component and is positioned on the lower surface of the lower plate-like portion 114 of the frame 110. Also, as shown in Figure 3, the gasket 178 fills the gap between the frame 110 and the cooler 190 when the frame 110 and the cooler 190 are joined together.

[0070] The gasket 178 positioned between the cooler 190 and the lower plate-shaped portion 114 is an example of "other waterproofing material" in this disclosure. The gasket 178 positioned between the lid member 182 and the upper plate-shaped portion 112 and the gasket 178 positioned between the cooler 190 and the lower plate-shaped portion 114 may be the same part or different parts. Furthermore, these two gaskets 178 may be integrated.

[0071] Next, the manufacturing procedure for the battery pack 102 in this embodiment will be described.

[0072] (Manufacturing procedure) First, as shown in Figures 9 and 10, the first frame piece 150L and the second frame piece 160L are welded together to create the left frame piece 140L. Similarly, the right frame piece 140R is also created.

[0073] Next, as shown in Figures 6 and 11, the front frame piece 120, the rear frame piece 130, the left frame piece 140L, and the right frame piece 140R are welded together on all four sides to create the frame 110.

[0074] Next, as shown in Figure 3, the beam member 118 is welded across the wall portion 156L of the left frame piece 140L and the wall portion 156R of the right frame piece 140R. It is preferable that the frame 110 to which the beam member 118 is welded is painted with an electrically insulating paint.

[0075] Next, the cooler 190 is fixed to the underside of the frame 110 with the gasket 178 in between. More specifically, as shown in Figure 3, the cooler 190 is fixed to the underside of the frame 110 from the underside of the frame 110 using bolts 109 inserted into each through hole 196, with the gasket 178 in between.

[0076] Next, as shown in Figure 3, the battery modules 180 are placed inside the frame 110. Each battery module 180 is in direct contact with the upper surface of the cooler 190 and is supported by the beam members 118.

[0077] Next, connectors (not shown) are attached to the holes 129 in the front frame piece 120 and the holes 139 in the rear frame piece 130. These connectors (not shown) are then electrically connected to the battery module 180.

[0078] Then, as shown in Figure 2, the lid member 182 is fixed to the upper side of the frame 110 with the gasket 178 in between. More specifically, as shown in Figure 2, the lid member 182 is fixed to the upper surface of the frame 110 from the upper side of the frame 110 using bolts 109 inserted into each through hole 186, with the gasket 178 in between.

[0079] As a result, for example, the gasket 178 is fixed in place between the left frame piece 140L and the lid member 182, as shown in Figure 12. Similarly, the gasket 178 is fixed in place between the left frame piece 140L and the cooler 190, as shown in Figure 12. The same applies to the front frame piece 120, the rear frame piece 130, and the right frame piece 140R. In other words, the gasket 178 is fixed in place between the upper plate-like portion 112 of the frame 110 and the lid member 182. The gasket 178 is also fixed in place between the lower plate-like portion 114 of the frame 110 and the cooler 190.

[0080] The battery pack 102 in this embodiment is manufactured by the procedure described above. The battery pack 102 is installed in the space below the cabin from below the vehicle 100, as shown in Figure 1. Cooling water piping (not shown) is connected to the inlet 194I and outlet 194O of the battery pack 102. This allows the vehicle 100 to store power for driving in the battery pack 102 and to draw power from the battery pack 102.

[0081] Next, we will explain the functions and effects of this disclosure.

[0082] The battery pack 102 has a frame 110 made of sheet metal. The top surface of the battery pack 102 is covered by a cover member 182, and the bottom surface of the battery pack 102 is covered by a cooler 190, which is in direct contact with the battery module 180.

[0083] Therefore, according to this embodiment of the battery pack 102, manufacturing costs (more specifically, the material cost of the frame 110) can be reduced compared to the case where the frame 110 is formed from an extruded material. Furthermore, according to this embodiment of the battery pack 102, since the battery module 180 and the cooler 190 are in direct contact, the cooling efficiency is improved compared to the case where a casing is used to waterproof the lower surface of the frame 110 and the cooler 190 and the battery module 180 are in indirect contact.

[0084] Furthermore, the battery pack 102 has a frame 110 which includes an upper plate-shaped portion 112 and a lower plate-shaped portion 114. The lid member 182 is fixed to the upper plate-shaped portion 112 with a gasket 178 in between, and the cooler 190 is fixed to the lower plate-shaped portion 114 with a gasket 178 in between. Therefore, according to this embodiment of the battery pack 102, waterproofing of the battery module 180 is ensured.

[0085] Furthermore, the battery pack 102 has a frame 110 whose four sides are each composed of a front frame piece 120, a rear frame piece 130, a left frame piece 140L, and a right frame piece 140R. Each frame piece is integrated by overlapping with the adjacent frame piece. Therefore, according to this embodiment of the battery pack 102, it is possible to reduce manufacturing costs (more specifically, processing costs) compared to when the frame 110 is made from a single sheet of metal.

[0086] Furthermore, this battery pack 102 has a closed structure because the left frame piece 140L and the right frame piece 140R are joined to the first frame piece 150 and the second frame piece 160. Therefore, the strength of the battery pack 102 according to this embodiment is improved compared to the case where all frame pieces have an open structure.

[0087] Furthermore, in this battery pack 102, the front frame piece 120 and the rear frame piece 130 are bent at both ends of the wall portions 126 and 136 such that the inside of the frame 110 is on the inside of the bend. Therefore, the strength of the battery pack 102 according to this embodiment is improved compared to the case where all frame pieces are flat in the direction in which their respective wall portions 126 and 136 extend.

[0088] (modified version) In the above description, the frame 110 had an upper plate-like portion 112 and a lower plate-like portion 114. The battery pack 102 in this disclosure is not limited to this. That is, the battery pack 102 only needs to be able to ensure waterproofness between the frame 110 and the lid member 182, and waterproofness between the frame 110 and the cooler 190. In other words, the frame 110 may be configured to contact the lid member 182 at the upper edge of the wall portion 126, or to contact the cooler 190 at the lower edge of the wall portion 126.

[0089] Furthermore, in the above description, the frame 110 was formed by a front frame piece 120, a rear frame piece 130, a left frame piece 140L, and a right frame piece 140R, which were divided in the front-rear and left-right directions, respectively. The battery pack 102 in this disclosure is not limited thereto. For example, the frame 110 may be formed by bending a single sheet of metal. That is, each frame piece forming each side of the rectangle may be connected in any part from the first to the fourth side.

[0090] Furthermore, in the above description, the left frame piece 140L and the right frame piece 140R had a first frame piece 150 and a second frame piece 160, and were in a closed structure. The battery pack 102 in this embodiment is not limited to this. For example, if the first frame piece 150 alone can have sufficient strength as a battery pack 102, the battery pack may be configured without the second frame piece 160.

[0091] Furthermore, in the above description, both the front frame piece 120 and the rear frame piece 130 were bent at both ends in the left-right direction. However, the shape of the battery pack 102 in this embodiment is not limited to this. That is, as long as sufficient strength of the frame 110 can be ensured, the front frame piece 120 and the rear frame piece 130 may be in a configuration where both ends are not bent.

[0092] While embodiments of this disclosure have been described above with reference to the attached drawings, it is clear that any person with ordinary skill in the art to which this disclosure belongs could conceive of various modifications or applications within the scope of the technical idea described in the claims, and these too are naturally understood to fall within the technical scope of this disclosure. [Explanation of symbols]

[0093] 100 vehicles 108 Weld Nut 102 Battery Pack 110 frames 112 Upper plate part 114 Lower plate part 116 Wall section 118 Beam members 119 Waterproofing agent 120 Front frame piece (an example of a frame piece) 122 Upper plate part 124 Lower plate part 126 Wall section 128 holes 129 holes 130 Rear frame piece (an example of a frame piece) 132 Upper plate part 134 Lower plate part 136 Wall section 138 holes 139 holes 140L Left side frame piece (an example of a frame piece) 140R Right side frame piece (an example of a frame piece) 150 First frame piece (an example of a first frame piece) 152 First upper plate-like portion (an example of the first upper plate-like portion) 154 First lower plate-like section (an example of the first lower plate-like section) 156 Wall section 160 Second frame piece (an example of a second frame piece) 162 Second upper plate-like part (an example of a second upper plate-like part) 164 Second lower plate-like section (an example of the second lower plate-like section) 166 Second wall section 168 through holes 178 Gasket (Example of waterproofing material, other examples of waterproofing materials) 180 Battery Modules 182 Lid member 186 Through hole 190 Cooler 192 Channels 196 Through hole 194I Inlet 194O Outlet

Claims

1. A frame made of sheet metal, with a frame-like structure on all four sides, A battery module is located inside the frame, A cover member fixed to the upper end of the frame and covering the upper surface of the battery module, A cooler is fixed to the lower end of the frame, covers the lower surface of the battery module, and cools the battery module by directly contacting it. A battery pack equipped with these features.

2. The frame has plate-shaped upper plate-like portions at the upper ends of each of its four sides, and plate-shaped lower plate-like portions at the lower ends of each of its four sides. The lid member is fixed to the upper plate-like portion with a waterproofing material in between. The cooler is fixed to the lower plate-shaped portion with other waterproofing material in between. The battery pack according to claim 1.

3. The frame is composed of frame pieces, each of which has a wall surface connecting the upper plate-like portion and the lower plate-like portion. The plurality of frame pieces are integrated by overlapping the frame pieces on adjacent sides with the upper plate-like portion, the lower plate-like portion, and the wall portion. The battery pack according to claim 2.

4. At least one of the frame pieces is joined to a second frame piece which has a second wall portion facing the wall portion, a second upper plate portion which is plate-shaped and overlaps the upper plate portion, and a second lower plate portion which is plate-shaped and overlaps the lower plate portion, so that the cross section viewed from the direction in which the frame piece extends is enclosed, forming a closed structure. The battery pack according to claim 3.

5. At least one of the frame pieces is bent such that both ends in the direction in which the wall portion of the frame piece extends are bent such that the inside of the frame is on the inside of the bend. The battery pack according to claim 3 or claim 4.

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