Battery pack shim, battery pack manufacturing method, and battery pack

Abstract

To make a battery pack of a secondary battery vibration-resistant with a simple configuration.SOLUTION: A shim for a battery pack for performing dimensional coordination in a gap between a battery case 12 and a battery stack 11 in a battery pack 10 in which the battery stack 11 is accommodated in the battery case 12, comprises: contact parts 3a, 3b composed of a pair of plate-like members in contact with an inner wall surface of the battery stack 11 or the battery case 12; a main body part 2 provided between the pair of contact parts 3a, 3b; a first space 6a provided inside the main body part and a second space 6b provided adjacent thereto; and fluid 7 filled into the spaces. The first space 6a and the second space 6b are communicated with each other through a gap 5 that is a narrowed structure. The fluid 7 filled into the first space 6a and the second space 6b is movable between the adjacent spaces through the gap 5 according to a force applied to the contact part 3b.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a shim for a battery pack, a manufacturing method for a battery pack, and a battery pack, and more particularly to a shim for a battery pack that is resistant to vibration, a manufacturing method for a battery pack, and a battery pack. [Background technology]

[0002] In recent years, high voltage and high current have been supplied by battery packs equipped with multiple battery stacks of secondary batteries, each consisting of a large number of stacked and connected cell batteries, for use as a driving power source for electric vehicles, etc. Examples of such secondary batteries include non-aqueous electrolyte secondary batteries such as lithium-ion secondary batteries and alkaline secondary batteries such as nickel-metal hydride batteries.

[0003] Such battery packs are mounted on vehicles, and for safety and to maintain battery performance, a battery stack is formed by stacking a large number of plate-shaped cell batteries in the thickness direction, and this constrained battery stack is housed in a case.

[0004] 27 is a schematic diagram of a conventional shim 100 for a battery pack. In an in-vehicle battery pack 10, a plate-shaped adjustment member called a "shim" is sometimes used to fill the gap between the battery stack 11 and the battery case 12 and adjust the restraining force so that the battery stack 11 does not shake due to vehicle vibrations or the like.

[0005] In the invention described in Patent Document 1, a shim of appropriate dimensions is produced by injecting a resin or the like to fit the gap between the battery case and the battery stack and hardening it, thereby producing a battery pack with the appropriate restraining force. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-87704 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a battery pack is installed in a vehicle, vibrations of various wavelengths are transmitted while the battery pack is running. Among these vibrations, there are some that resonate with the length of the battery stack. When vibrations of a wavelength that causes such resonance are received, the battery stack inside the battery pack may vibrate in a large undulating manner.

[0008] The shim described in Patent Document 1 can usually suppress vibrations with a predetermined restraining force. However, when vibrations of a frequency that causes resonance occur, the restraining force of the shim must be increased to suppress the vibrations. This requires increasing the strength of the cell battery itself and the battery pack structure. This leads to problems such as a complicated battery pack structure, increased mass, and higher manufacturing costs.

[0009] An object of the battery pack shim, the battery pack manufacturing method, and the battery pack of the present invention is to make the battery pack resistant to vibration with a simple structure. [Means for solving the problem]

[0010] In order to solve the above problem, the shim for a battery pack of the present invention is a shim for a battery pack that adjusts the size of the gap between a battery case and a battery stack that houses a battery stack in which multiple battery cells are stacked in a battery case, and is characterized in that it comprises: a contact portion consisting of a pair of plate-shaped members that contact the inner wall of the battery stack or the battery case; a main body portion that is provided between the pair of contact portions and has an airtight space made of a flexible material; a first space that contacts both of the pair of contact portions provided in the main body portion; a second space that is adjacent to the first space and contacts both of the pair of contact portions; and a fluid filled in the first space and the second space, the first space and the second space being connected via an aperture structure, and the fluid filled in the first space and the second space being configured to be able to move between the adjacent spaces via the aperture structure in response to a force applied to the abutment portion.

[0011] The throttle structure may be formed by a gap between a pair of protrusions that protrude from the pair of contact portions in opposing directions. The gap between the pair of protrusions may be formed as a slit extending in the horizontal direction. The pair of protrusions may have horizontal linear ridges. The ridges of the pair of protrusions may be formed to be offset in the vertical direction. The pair of protrusions may have a triangular vertical cross section. The pair of protrusions may be formed from a diaphragm filled with liquid. The diaphragm of the protrusion may be formed from a flexible resin, and a folding portion that can expand and contract in the horizontal direction may be formed in the diaphragm as the main body expands and contracts. The pair of protrusions may be formed from a solid.

[0012] The fluid filled in the main body preferably has a viscosity of 1 to 10 Pa / s. The main body may include an injection hole that allows the fluid to be injected from the outside and seals the injected fluid.

[0013] The pair of contact portions may be provided with a restricting portion for restricting misalignment by interfering with misalignment in the vertical and horizontal directions. The throttle structure may be configured by an orifice provided in a diaphragm that separates the first space and the second space.

[0014] Furthermore, the shim for a battery pack of the present invention may be a shim for a battery pack that adjusts the size of a gap between a battery case and a battery stack in a battery pack in which a battery stack, formed by stacking multiple battery cells in a battery case, is housed from above, and that includes: a pair of abutment portions made of plate-shaped members that abut against the inner wall of the battery stack or the battery case; a main body portion that is provided between the pair of abutment portions and has an airtight space made of a flexible material; a third space that is provided within the main body and is formed in contact with one of the pair of abutment portions; a fourth space that is connected to the third space and is formed in contact with the other of the pair of abutment portions; and a fluid that is filled in the third space and the fourth space, wherein the third space and the fourth space are connected via an aperture structure that is fixed in position to one of the pair of abutment portions and is configured so that the fluid filled in the third space and the fourth space can move between adjacent spaces via the aperture structure in response to a force applied to the abutment portions.

[0015] The battery pack shim of the present invention is a battery pack shim for adjusting the size of a gap between a battery case and a battery stack in a battery pack in which a battery stack, which is made of a plurality of stacked battery cells, is housed from above in a battery case, and includes a pair of abutment parts made of plate-like members that abut against the inner wall of the battery stack or the battery case, a main body part provided between the pair of abutment parts and having an airtight space made of a flexible material, a fifth space formed in the main body part and abutting one of the pair of abutment parts, a sixth space communicating with the fifth space and abutting the other of the pair of abutment parts, and a space between the sixth space and the abutment part. a seventh space adjacent to the fifth space with a gap therebetween, communicating with the fifth space and formed in contact with the other of the pair of contact portions; and fluids filled in the fifth space, the sixth space, and the seventh space, wherein the fifth space and the sixth space, and the fifth space and the seventh space, are communicated via an aperture structure, and the aperture structure is fixed in position to one of the pair of contact portions, and is configured so that the fluids filled in the fifth space and the sixth space, and the fifth space and the seventh space, can move between adjacent spaces via the aperture structure in response to a force applied to the contact portions.

[0016] The fifth space may be further divided by a throttle structure into a portion communicating with the sixth space and a portion communicating with the seventh space, and the fluid filled in the portion communicating with the sixth space and the portion communicating with the seventh space may be configured to be able to move between adjacent spaces via the throttle structure in response to a force applied to the abutment portion.

[0017] The method for manufacturing a battery pack of the present invention includes a restraining step of pressing a battery stack formed by stacking a plurality of battery cells in a stacking direction to restrain the battery stack, a battery stack inserting step of inserting the battery stack in a restrained state into a battery case, and a battery pack inserting step of inserting the battery stack in a restrained state into a battery case. The battery pack inserting step includes a main body having an airtight space made of a flexible material and a pair of abutting portions made of a pair of plate-like members that abut against the battery stack or an inner wall of the battery case, a first space that abuts against both of the pair of abutting portions provided in the main body, and a second space that abuts against the first space and that abuts against the first space. The battery pack includes a second space in contact with both of the pair of abutment portions, and a fluid filled in the first space and the second space, the first space and the second space being connected via a throttle structure, and the fluid filled in the first space and the second space is configured to be able to move between adjacent spaces via the throttle structure in response to a force applied to the abutment portions. The battery pack also includes a shim insertion process for inserting a shim into a space between an end face in the stacking direction of the battery stack and an inner wall surface of the battery case facing the end face.

[0018] The shim insertion process includes a shim compression process of compressing the shim for the battery pack in a stacking direction, a process of inserting the compressed shim into a space between an end face of the battery stack in the stacking direction and an inner wall surface of the battery case facing the end face, and a process of releasing the compression after insertion to press the shim against the end face of the battery stack in the stacking direction and the inner wall surface of the battery case facing the end face.

[0019] The shim insertion process may include inserting the shim into a space between an end face of the battery stack in the stacking direction and an inner wall surface of the battery case facing the end face, and injecting the fluid into the main body portion after the insertion, thereby pressing the shim against the end face of the battery stack in the stacking direction and the inner wall surface of the battery case facing the end face.

[0020] The battery pack of the present invention is a battery pack that includes the battery pack shim, houses a battery stack in which a plurality of battery cells are stacked in a battery case, and uses the battery pack shim to adjust the dimensions of the gap between the battery case and the battery stack, and is characterized in that the battery cells directly abut the battery pack shim on a side of the battery stack that faces the battery pack shim, and the battery cells abut against the inner wall of the battery case via an end plate on a side different from the side that faces the battery pack shim. [Effects of the Invention]

[0021] The battery pack shim, the battery pack manufacturing method, and the battery pack of the present invention can make the battery pack resistant to vibration with a simple structure. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a perspective view of the appearance of the battery pack. [Figure 2] FIG. 2 is a perspective view of a battery stack housed in the battery pack. [Figure 3] FIG. 2 is a perspective view showing a battery case of a battery pack that houses a battery stack. [Figure 4] 5A to 5C are schematic diagrams showing a procedure for inserting a battery pack shim into the battery pack of the first embodiment. [Figure 5] 10A to 10C are schematic diagrams showing a procedure for pressing a battery pack shim against a battery pack. [Figure 6] 10A and 10B are schematic diagrams showing the action of the battery pack shim when the battery stack is oscillated. [Figure 7] 10A and 10B are schematic diagrams showing the action of the battery pack shim when the battery stack is oscillated. [Figure 8] 10 is a graph comparing the vibration amplification factor according to frequency [Hz] of the battery pack shim of the prior art and the present embodiment. [Figure 9] FIG. 2 is a perspective view showing the appearance of a shim for a battery pack. [Figure 10] FIG. 2 is an exploded perspective view of the battery pack shim when contracted. [Figure 11] FIG. 10 is a view showing the folded portion of the membrane of the protrusion unfolded. [Figure 12] FIG. 10 is a view showing the folded portion of the diaphragm of the protrusion folded. [Figure 13] FIG. 10 is a perspective view showing the shim for the battery pack when contracted. [Figure 14] FIG. 2 is a perspective view showing the battery pack shim when expanded. [Figure 15] FIG. 2 is a plan view showing the appearance of the battery pack shim. [Figure 16] FIG. 2 is a front view showing the appearance of the battery pack shim. [Figure 17] 17 is a cross-sectional view taken along line 17-17 of FIG. 16. [Figure 18] 18-18 cross-sectional view of FIG. 16. [Figure 19] FIG. 18 is a partial cross-sectional view taken along line 18-18 of FIG. 16 during contraction. [Figure 20] FIG. 18 is a partial cross-sectional view taken along the line 18-18 in FIG. 16 when enlarged. [Figure 21] FIG. 2 is an exploded perspective view of the battery pack shim when enlarged. [Figure 22] 10A and 10B are schematic diagrams of a shim for a battery pack provided with a modified protrusion and a restricting portion. [Figure 23] FIG. 2 is a schematic diagram showing the arrangement of battery pack shims in the battery pack. [Figure 24] 10 is a schematic diagram of a shim for a battery pack for absorbing vibration in the stacking direction of a battery stack according to a second embodiment. FIG. [Figure 25] FIG. 10 is a schematic diagram of a shim for a battery pack according to a third embodiment. [Figure 26] 10A and 10B are schematic diagrams illustrating the operation of the shim for a battery pack according to the third embodiment. [Figure 27] FIG. 10 is a schematic diagram showing the configuration of a conventional shim for a battery pack. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, a battery pack shim and a method for manufacturing a battery pack according to the present invention will be described with reference to FIGS. 1 to 26 using an embodiment of a battery pack 10 of a lithium ion secondary battery and a battery pack shim 1. FIG.

[0024] <Battery pack configuration> Fig. 1 is a perspective view of the appearance of a battery pack 10. Fig. 2 is a perspective view of a battery stack 11 housed in the battery pack 10. Fig. 3 is a perspective view showing a battery case 12 of the battery pack 10 that houses the battery stack 11.

[0025] First, the basic configuration of the battery pack 10 will be described. When the battery pack 10 is mounted on a vehicle, a number of assembled batteries (two in this embodiment for the sake of explanation) are housed in an airtight container to prevent contamination or damage. This container is equipped with auxiliary devices such as a control device, external electrodes, etc., and is then sealed. In this embodiment, such incidental components will be omitted for the sake of explanation of the invention, and the battery pack 10 will be the one shown in FIG. 1.

[0026] First, the battery pack 10 shown in FIG. 1 has a battery stack 11, as shown in FIG. 2, housed in a battery case 12, as shown in FIG. 3. The battery stack 11 is an assembled battery in which a large number of rectangular plate-shaped battery cells 13 (34 in FIG. 2) are stacked and restrained in the thickness direction of the battery cells 13. Conventionally, end plates made of metal or resin are placed on both ends of the stacked battery cells 13. When viewed in the stacking direction, the end plates 14 have substantially the same shape as the battery cells 13. The battery stack 11 is tightly restrained in the stacking direction from the outside of the end plates 14, which are placed on both ends of the stacked battery cells 13, by, for example, belt-like restraining members. Therefore, both ends of the stacked battery cells 13 are configured so that the end plates 14 apply a uniform restraining force to the entire surfaces of the battery cells 13.

[0027] The battery pack shim 1 of this embodiment can also be additionally used in a battery stack 11 having both ends sandwiched between a pair of end plates 14 like this. Furthermore, in this embodiment, as shown in Fig. 1, the battery pack shim 1 of this embodiment can be used as an end plate instead of one of the end plates 14. In this case, the end plate 14 is not disposed on the surface of the battery stack 11 that faces the battery pack shim 1. As a result, the battery pack shim 1 directly contacts the battery cell 13. In this embodiment, since the battery pack shim 1 is used as an end plate instead of one of the end plates 14, the other end plate is not necessary.

[0028] <Problems with the prior art> FIG. 27 is a schematic diagram showing the configuration of a conventional battery pack 10. A conventional battery pack shim 100 is housed in a battery case 12 and inserted into an opening AP between one inner wall surface 12a of the battery case 12 and the housed battery stack 11. The conventional battery pack shim 100 is made of a hard resin or the like to maintain a restraining force. When inserting the conventional battery pack shim 100 into the gap between the other inner wall surface 12a of the battery case 12 and the housed battery stack 11, several thicknesses of battery pack shims 100 are prepared and selected to match the opening AP. Alternatively, as disclosed in Patent Document 1, the thickness is adjusted by filling and hardening a resin. In either case, the battery pack shim 100 is inserted as a hard battery pack shim. The battery stack 11 is restrained by a restraining member 11c so that pressure is applied in the stacking direction. Therefore, the stacked battery stack 11 is fixed as a whole. However, when the battery pack 10 is mounted on a vehicle or the like, the battery stack 11 vibrates due to the violent up-and-down movement. Even if the battery pack shim 100 is tightly inserted into the opening AP, if the frequency of the up-and-down movement matches the inherent resonant frequency of the battery stack 11, the battery stack 11 resonates and generates violent up-and-down movement accompanied by undulations. In order to suppress the vibration of the battery stack 11, it may be necessary to increase the rigidity of the battery case 12 to match the maximum amplitude or to use a restraining member 11c to suppress the vibration. This results in an increase in mass, a complex structure, and higher production costs.

[0029] <Features of the battery pack shim 1 of this embodiment> FIG. 4 is a schematic diagram showing the procedure for inserting the battery pack shim 1 into the battery pack 10 of the first embodiment.

[0030] 4, in the battery pack 10 of this embodiment, a battery stack 11 is housed in a battery case 12. An end face 11b on the rear side of the battery stack 11 contacts an inner wall surface 12b on the rear side of the battery case 12. An end face 11a on the front side of the battery stack 11 is separated from the inner wall surface 12a on the rear side of the battery case 12 and has an opening AP.

[0031] The battery pack shim 1 of this embodiment has a back surface having abutment portions 3b made of a pair of plate-shaped members that abut against the end surface 11a of the battery stack 11. The front surface has abutment portions 3a that abut against the inner wall surface 12a of the battery case 12. The battery pack shim 1 is inserted into the opening AP.

[0032] The battery pack shim 1 of this embodiment has a main body 2 that is provided between a pair of contact portions 3a, 3b and has an airtight space made of a flexible material. The main body 2 has an upper first space 6a that contacts both of the pair of contact portions 3a, 3b provided within the main body 2. The main body 2 also has a second space 6b that is adjacent to the first space 6a on the lower side and contacts both of the pair of contact portions 3a, 3b. The first space 6a and the second space 6b are filled with a fluid 7. The first space 6a and the second space 6b are in communication with each other via a gap 5 that forms a throttle structure.

[0033] The fluid 7 filled in the first space 6a and the second space 6b is configured to be movable between the adjacent first space 6a and second space 6b through the gap 5, which is a throttle structure, in response to the force applied to the abutment parts 3a and 3b.

[0034] <Fixing battery pack shim 1> 5 is a schematic diagram showing the procedure for pressing the battery pack shim 1 against the battery pack 10. As shown in FIG. 5, the battery pack shim 1 has an injection hole 25 in the upper part 21 of the main body 2. The injection hole 25 receives the fluid 7 so that it can be injected from the outside, and functions as a check valve that seals the fluid 7 after injection to prevent backflow and store it inside the main body 2.

[0035] The liquid injection device 15 has a pressure injection section 15a that stores the fluid 7 and pushes it out by applying pressure, and an injection tube 15b that injects the fluid 7 into the main body section 2 from the pressure injection section 15a.

[0036] When pressurized fluid 7 is injected into the main body 2 by the fluid injection device 15, the stretchable main body 2 stretches in the stacking direction of the battery stack 11. Before the fluid 7 was injected, the thickness D1 of the battery pack shim 1 shown in FIG. 4 was smaller than the opening AP by the gap G, allowing the battery pack shim 1 to be easily inserted into the opening AP. After the fluid 7 was injected, the thickness D2 of the battery pack shim 1 becomes equal to the width of the opening AP, as shown in FIG. 5. Furthermore, the contact portion 3b presses the battery stack 11 with a predetermined pressure, thereby restraining the battery stack 11 within the battery case 12. By fixing the battery stack 11 within the battery case 12 in this way, the battery stack 11 does not rattle due to normal vibrations.

[0037] <Function of Battery Pack SIM 1> FIG. 6 is a schematic diagram showing the action of the battery pack shim 1 when the battery stack 11 swings.

[0038] When the vehicle vibration reaches the resonant frequency of the battery stack 11, the amplitude is amplified and the battery stack 11 vibrates in an undulating manner. At this time, as shown in Figure 6, when the center of the battery stack 11 jumps upward, the contact portion 3b tilts counterclockwise from the state shown in Figure 5. This causes the thickness D3 to decrease and the space 6a to compress. Meanwhile, the thickness D4 increases and the space 6b expands. At this time, the overall capacity of the main body 2 does not change, so the fluid 7 filling the space 6a passes through the gap 5 and moves into the space 6b.

[0039] Here, the gap 5 has a small cross-sectional area. The fluid 7 is a highly viscous liquid with a viscosity of 1 to 10 Pa / s. Therefore, viscous resistance occurs when the fluid 7 passes through the gap 5. Viscous resistance is proportional to speed. Therefore, when the fluid 7 passes through the gap 5 slowly, the fluid 7 passes smoothly through the gap 5, generating almost no resistance. However, when a large-amplitude vibration is applied to the battery stack 11, the acceleration applied to the contact portion 3b also increases. The increased acceleration applied to the contact portion 3b leads to more drastic volumetric changes in the spaces 6a and 6b, and the speed at which the fluid 7 passes through the gap 5 also increases. This significantly increases the viscous resistance when the fluid 7 passes through the gap 5. This viscous resistance suppresses the volumetric changes in the spaces 6a and 6b, thereby suppressing tilting of the contact portion 3b. Suppressing the tilting of the contact portion 3b consequently suppresses sudden vibrations of the battery stack 11.

[0040] That is, the battery pack shim 1 itself functions as a damper device equivalent to a so-called dashpot. FIG. 7 is a schematic diagram showing the action of the battery pack shim 1 when the battery stack 11 is swung in the opposite direction to that shown in FIG.

[0041] When the end of the battery stack 11 flips upward, the contact portion 3b tilts clockwise from the state shown in Figure 5. This causes the thickness D5 to increase and the space 6a to expand. Meanwhile, the thickness D6 decreases and the space 6b shrinks. At this time, the overall capacity of the main body 2 remains unchanged, so the fluid 7 filling the space 6b passes through the gap 5 and moves into the space 6a.

[0042] When large-amplitude vibrations are applied to the battery stack 11, the acceleration applied to the contact portion 3b also increases. As the acceleration applied to the contact portion 3b increases, the volumetric changes in the spaces 6a and 6b become more intense, and the speed at which the fluid 7 passes through the gap 5 also increases. This causes a sudden increase in viscous resistance when the fluid 7 passes through the gap 5. This viscous resistance therefore suppresses the volumetric changes in the spaces 6a and 6b, thereby suppressing the tilting of the contact portion 3b. Suppressing the tilting of the contact portion 3b results in suppressing sudden vibrations of the battery stack 11.

[0043] As described above, in the battery pack shim 1 of this embodiment, when the vibration of the battery stack 11 becomes large, the tilting of the abutment portion 3b is suppressed from both directions, thereby effectively suppressing the undulation of the battery stack 11.

[0044] <Advantages of the First Embodiment> Fig. 8 is a graph comparing the vibration amplification factor (as a function of frequency [Hz]) of the battery pack shim 1 of the prior art and the present embodiment. In Fig. 8, the dashed curve L1 indicates the amplification factor (%) of the vibration of the battery stack 11 with respect to the input vibration and with respect to the change in frequency [Hz] when using the battery pack shim 100 of the prior art. On the other hand, the solid curve L2 indicates the amplification factor (%) of the vibration of the battery stack 11 with respect to the input vibration and with respect to the change in frequency [Hz] when using the battery pack shim 1 of the present embodiment.

[0045] Looking at the conventional curve L1, the vibration amplification factor increases significantly at peak P1. This occurs when the input frequency [Hz] matches the resonant frequency of the battery stack 11, causing resonance. The amplitude of the battery stack 11 at this time is large. On the other hand, looking at the curve L2 of this embodiment, it is clear that the increase in the vibration amplification factor is effectively suppressed at peak P2. This occurs when the input frequency [Hz] matches the resonant frequency of the battery stack 11, but the battery pack shim 1 effectively suppresses resonance. The amplitude of the battery stack 11 at this time is small.

[0046] (Example) Hereinafter, an example will be described showing a specific configuration example of the battery pack shim 1 of the first embodiment explained using the schematic diagram.

[0047] <Appearance of battery pack SIM 1> FIG. 9 is a perspective view showing the appearance of the battery pack shim 1. As shown in FIG. 2, the battery pack shim 1 has the same height and width as the battery cell 13. It has a rectangular parallelepiped appearance overall, with a rectangular contact portion 3a on the front side in the stacking direction and a contact portion 3b with the same shape as contact portion 3a on the back side. The upper surface is provided with an upper portion 21 of the main body portion 2, and the lower surface (not shown) is provided with a lower portion 22 of the main body portion 2. The left side surface is provided with a left portion 23 of the main body portion 2, and the right side surface (not shown) is provided with a right portion 24 of the main body portion 2. The center portion of the main body portion 2 in the stacking direction is recessed in a groove-like shape.

[0048] <Structure of battery pack shim 1> FIG. 10 is an exploded perspective view of the battery pack shim 1 when contracted. <Contact part 3 (3a, 3b)> The front-side contact portion 3a and the rear-side contact portion 3b are hard plate-like members of the same size as the battery cells 13, and are made of a hard material such as hard polypropylene (PP), iron, or aluminum. The rear-side contact portion 3b has high rigidity relative to the front-side end face 11a of the battery stack 11, just like the end plate 14 (Fig. 1), and functions to ensure a uniform restraining force.

[0049] <Protrusion 4 (4a, 4b)> The protrusions 4 are formed on the inner surface of the front contact portion 3a and the rear contact portion 3b, and are made of a flexible material such as rubber or PP in the form of a film.

[0050] FIG. 11 is a diagram showing the folded portion 43 of the diaphragm 42 of the protrusion 4 unfolded. FIG. 12 is a diagram showing the folded portion 43 of the diaphragm 42 of the protrusion 4 folded. As shown in FIG. 11, the protrusion 4 is formed from a single rectangular sheet. First, the rectangular sheet is folded so that the horizontal line at the center of the height direction forms a mountain fold (the front side of the drawing is convex), with ridge line 41 as the fold line. At the same time, fold line 1 (mountain fold) 43a is formed linearly from point 41a of ridge line 41 at the side edge of the sheet to the upper and lower vertices. Point 41b is set outward from point 41a, and fold line 2 (valley fold) 43b is formed linearly from point 41b to the upper and lower vertices. Furthermore, point 41c is set outward from point 41b, and fold line 3 (mountain fold) 43c is formed linearly from point 41c to the upper and lower vertices.

[0051] By folding along the creases of the ridge line portion 41 and the folded portion 43, a roof-like protrusion 4 is formed, which is a triangular prism with a roughly isosceles triangular base, as shown in Figure 12. The periphery of the protrusion 4 thus formed is bonded to the abutting portion 3. The space formed by the protrusion 4 thus formed and the abutting portion 3 is filled with a filler 45 made of liquid or gas.

[0052] In addition, as shown in Figure 10, the isosceles triangular portion formed between the fold 43c and the sheet end is adhered to the portions indicated by the dashed dotted lines at the ends of the left side portion 23 and the right side portion 24 of the main body portion 2.

[0053] The protrusions 4 (4a, 4b) are formed by being filled with the filler 45 in this way, and therefore have an airtight structure that is not easily crushed by pressure. <Main body part 2 (21a, 21b, 21c, 21d)> The main body 2 is formed between a pair of parallel abutment portions 3 (3a, 3b) arranged opposite to each other. Each of the main body portions 2 has a sheet structure made of flexible rubber or a resin such as PP. The main body 2 is made up of an upper portion 21 arranged on the top surface, a lower portion 22 arranged on the bottom surface, a left portion 23 arranged on the left side, and a right portion 24 arranged on the right side.

[0054] The upper part 21, which is disposed on the upper surface, is airtightly adhered to the upper ends of the abutment parts 3 (3a, 3b). The lower part 22, which is disposed on the lower surface, is airtightly adhered to the lower ends of the abutment parts 3 (3a, 3b). The left part 23, which is disposed on the left surface, is airtightly adhered to the left ends of the abutment parts 3 (3a, 3b). The right part 24, which is disposed on the right surface, is airtightly adhered to the right ends of the abutment parts 3 (3a, 3b). Therefore, the main body part 2 remains airtight.

[0055] <Injection hole 25> An injection hole 25 is provided in the center of the upper part 21 of the main body 2. As explained in Fig. 5, injection hole 25 allows fluid 7 to be injected into the main body 2 under pressure, and after the fluid 7 is injected, it restricts the outflow of the fluid 7 and maintains the pressure inside the main body 2. A well-known check valve can be used for this configuration.

[0056] <Fluid 7> The fluid 7 is filled inside the main body 2 and functions as damper oil. In this embodiment, a silicone oil with a viscosity of 1 to 10 Pa / s is used as the fluid 7. Silicone oil is generally a colorless, transparent liquid with excellent heat resistance, cold resistance, and water resistance. It also has little change in viscosity over a wide temperature range and excellent electrical properties. It also has antifoaming and lubricating properties, making it suitable for use as the fluid in this embodiment. A specific example is dimethyl silicone oil KF-96H manufactured by Shin-Etsu Chemical Co., Ltd.

[0057] The fluid 7 is not limited to oil, and a high viscosity polymer solution, such as an aqueous solution of a cellulose derivative or an aqueous solution of a polyacrylic acid derivative, can also be used. <Function of the battery pack shim 1 of the embodiment> Fig. 13 is a perspective view showing the battery pack shim 1 when contracted. Fig. 14 is a perspective view showing the battery pack shim 1 when expanded. When the battery pack shim 1 is inserted into the battery case 12 as shown in Fig. 4, the thickness D1 is made smaller than the opening AP. Therefore, the inside of the main body 2 is not filled with fluid 7 or is filled with only a small amount.

[0058] After insertion, the fluid 7 is injected through the injection hole 25 . As a result, the thickness of the main body 2 increases, and as shown in FIG. 14, the thickness D2 becomes equal to the thickness of the opening AP, and the contact portion 3b presses against the end face 11a of the battery stack 11 with a predetermined pressure.

[0059] At this time, the volume of the main body 2 increases due to the fluid 7 being filled, and the groove-like curve toward the inside becomes smaller. Also, the opposing contact portions 3a and 3b move away from each other while maintaining a parallel relationship.

[0060] <Internal structure of battery pack shim 1 according to the embodiment> Fig. 15 is a plan view showing the appearance of the battery pack shim 1. Fig. 16 is a front view showing the appearance of the battery pack shim 1. Fig. 17 is a cross-sectional view taken along line 17-17 of Fig. 16, perpendicular to the stacking direction at the center in the width direction.

[0061] Next, the internal structure of the battery pack shim 1 of the embodiment will be described. A fluid 7 is filled between the upper portion 21 and the lower portion 22 of the main body portion 2, sandwiched between the opposing contact portions 3a and 3b. Furthermore, roof-like protrusions 4a and 4b are formed on the contact portions 3a and 3b, respectively, so as to face each other. A filler 45 is filled inside the protrusions 4a and 4b. The protrusions 4a and 4b are formed so that horizontal ridge portions 41 are close to each other, and a gap 5 is formed between the ridge portions 41. The gap 5 has a throttle structure with a small cross-sectional area, forming a flow path.

[0062] Figure 18 is a horizontal cross-sectional view taken along line 18-18 in the stacking direction at the center of the height direction in Figure 16. Ridge lines 41, 41 of protrusions 4a, 4b face each other in parallel, forming a slit-like gap 5. Folded portions 43, 43 are formed at both ends of protrusions 4a, 4b.

[0063] <Function of the folding portion 43> FIG. 19 is a partial cross-sectional view taken along line 18-18 of FIG. 16 during contraction. 11 and 12, the folding portion 43 has a shape folded along fold line 1 (mountain fold) 43a, fold line 2 (valley fold) 43b, and fold line 3 (mountain fold) 43c. The left side portion 23 and the right side portion 24 of the main body 2 are curved inward to follow the folded folding portion 43 of the protruding portions 4a and 4b whose central portions are bonded to the inside.

[0064] FIG. 20 is an enlarged partial cross-sectional view taken along line 18-18 in FIG. 16. As described in FIG. 5, when pressurized fluid 7 is injected into the main body 2 by the fluid injection device 15, the expandable main body 2 expands in volume and expands in the stacking direction of the battery stack 11. Therefore, the thickness D1 of the battery pack shim 1 before the injection of the fluid 7 shown in FIG. 19 becomes the thickness D2 of the battery pack shim 1 after the injection of the fluid 7 shown in FIG. 20. At this time, the fluid 7 injected into the main body 2 exerts a force on the right side 24 of the main body 2 in FIG. 19. The fluid 7 injected into the main body 2 also exerts a force in the direction separating the protrusions 4a and 4b. Therefore, the right side 24 of the main body 2 deforms to become less curved and closer to a flat surface. The end of the protrusion 4 is bonded to the right side 24 of the main body 2. Therefore, the end of the protrusion 4 is pulled outward by the upper portion 21 of the main body 2. As a result, the fold 1 (mountain fold) 43a, fold 2 (valley fold) 43b, and fold 3 (mountain fold) 43c are stretched and deformed to approach a flat surface.

[0065] 20 is a partial cross-sectional view taken along line 18-18 in FIG. 16 when expanded. As described above, fold 1 (mountain fold) 43a, fold 2 (valley fold) 43b, and fold 3 (mountain fold) 43c are stretched and become nearly flat. In this way, by unfolding folded portion 43, thickness D2 can be achieved smoothly while abutting portions 3a and 3b remain parallel to each other without causing excessive deformation.

[0066] Figure 21 is an exploded perspective view of the battery pack shim 1 when expanded. As shown in Figures 19 and 20, unfolding the folding portion 43 prevents excessive deformation of the protruding portion 4. Therefore, by straightening the curves of the upper portion 21, lower portion 22, left portion 23, and right portion 24 that make up the main body portion 2 and making them closer to a flat surface, the spacing between the abutting portions 3a and 3b can be smoothly changed while maintaining their parallelism. This allows the thickness D of the battery pack shim 1 to be adjusted to any desired thickness D to match the opening AP.

[0067] (Effects of this embodiment) (1-1) The battery pack shim 1, the battery pack 10, and the manufacturing method thereof according to this embodiment have the advantage of being able to make the battery pack 10 resistant to vibration with a simple structure.

[0068] (1-2) The device includes a first space 6a and a second space 6b that contact both of a pair of contact portions 3a, 3b provided in the main body 2, and a fluid 7 filled therein. The first space 6a and the second space 6b are connected via a gap 5 that is a throttle structure. The device is configured so that the fluid 7 filled in the first space 6a and the second space 6b can move between the adjacent spaces via the gap 5 in response to a force applied to the contact portions 3a, 3b.

[0069] Therefore, the battery pack shim 1 has the effect of functioning as a damper that suppresses swell in the battery stack 11. (1-3) In particular, when the vibration of the vehicle reaches the resonant frequency of the battery stack 11, and the vibration is accompanied by a violent swell, this can be effectively suppressed.

[0070] (1-4) The shim 1 for the battery pack has the advantage that it can be made to any thickness and pressure by filling the main body 2 made of a flexible material with any amount of fluid 7.

[0071] (1-5) The throttle structure that generates the viscous resistance of the fluid 7 is due to the gap 5 formed by the protrusions 4a and 4b, and therefore has the effect of functioning even if the thickness of the battery pack shim 1 is changed.

[0072] (1-6) The battery pack shim 1 has elasticity by filling the body 2 made of a flexible material with an arbitrary amount of fluid 7. This has the effect of suppressing changes in the pressing force on the battery stack 11 even with use, allowing pressing with a constant pressure.

[0073] (1-7) The pair of protrusions 4a, 4b are formed from a diaphragm 42 filled with a filler 45 such as a liquid. This has the effect of simplifying the structure of the protrusions 4a, 4b.

[0074] (1-8) The diaphragm 42 of the protruding portion 4 is made of flexible PP resin or rubber. In addition, the diaphragm 42 has a folding portion 43 that can expand and contract horizontally in accordance with the expansion and contraction of the main body 2. Therefore, even if the main body 2 expands due to the injection of the fluid 7 when contracted, the deformation of the shape can be absorbed, and the thickness of the battery pack 10 can be smoothly adjusted.

[0075] (1-9) In this embodiment, the battery pack shim 1 is used as an end plate instead of the one end plate 14, which has the effect of making the other end plate unnecessary.

[0076] (Second embodiment) While the battery pack shim 1 of the first embodiment was intended to suppress vibrations caused by undulations of the battery stack 11, the battery pack shim 101 of the second embodiment differs in that it absorbs vibrations in the stacking direction.

[0077] FIG. 24 is a schematic diagram of a battery pack shim 101 for absorbing vibration in the stacking direction of the battery stack 11 of the second embodiment. The second embodiment has a basic configuration in common with the first embodiment, so the common configuration will be assigned the same reference numerals and explanations will be omitted, and only the differences will be explained.

[0078] A third space 6c and a fourth space 6d are provided in the main body 2 between the pair of contact portions 3a, 3b. The third space 6c and the fourth space 6d are airtight spaces made of a flexible material. The third space 6c is formed in contact only with the contact portion 3a. The fourth space 6d is formed in contact only with the contact portion 3b. The third space 6c and the fourth space 6d are filled with a fluid 7, and the third space 6c and the fourth space 6d are connected via a gap 5, which is a throttle structure.

[0079] The battery pack shim 101 of the second embodiment has an upper support portion 46a extending from the upper end of the contact portion 3a toward the contact portion 3b (back side), and a lower support portion 46b extending from the lower end of the contact portion 3a toward the contact portion 3b (back side). The tip of this support portion 46a has a protrusion 4c that protrudes toward the inside (downward) of the main body portion 2. The protrusion 4c is a roughly triangular prism that protrudes downward and extends in the width direction (direction perpendicular to the paper surface of FIG. 24). The protrusion 4c is formed of a solid, hard resin such as PP. Similarly, the tip of the support portion 46b has a protrusion 4d that protrudes toward the inside (upward) of the main body portion 2. The protrusion 4d is a roughly triangular prism that protrudes upward and extends in the width direction (direction perpendicular to the paper surface of FIG. 24). The protrusions 4c and 4d are formed of a solid hard resin such as PP. The protrusions 4c and 4d are configured to bring the ridges 41, 41 close to each other, and have a gap 5 that forms a slit, which is a throttle structure.

[0080] The fluid 7 filled in the third space 6c and the fourth space 6d is configured to be able to move between adjacent spaces through the gap 5, which is a throttle structure, in response to the force applied to the abutment portion 3b.

[0081] (Operation of the second embodiment) When the battery stack 11 presses the battery pack shim 101 (a force directed leftward in FIG. 24), the contact portion 3b is pressed against this force. At this time, the contact portion 3a also receives a reaction force from the battery case 12. At this time, the protrusions 4c and 4d are fixed to the contact portion 3a. As a result, the contact portion 3b approaches the protrusions 4c and 4d, and the volume of the fourth space 6d decreases. As a result, the fluid 7 in the fourth space 6d moves through the gap 5 into the third space 6c. At this time, the gap 5 acts as a throttle structure, applying viscous resistance to the passing fluid 7. Therefore, the fluid 7 pressed by the contact portion 3b moves slowly into the third space 6c. As a result, the battery pack shim 101 functions as a damper against vibrations in the stacking direction of the battery stack 11.

[0082] The damping effect will be more effective if the third space 6c is more easily deformed than the fourth space 6d of the main body 2. To achieve this, the ease of deformation can be controlled by changing the material or thickness of the wall surface, for example.

[0083] (Effects of the second embodiment) (2-1) The battery pack shim 101 of the second embodiment can effectively suppress vibrations of the battery stack 11 in the stacking direction.

[0084] (Modification of the second embodiment) Although the second embodiment shows an example in which one battery pack shim 101 is provided, a configuration in which a plurality of battery pack shims 101 are provided in one battery pack 10 to support the battery stack 11 may also be used. For example, by inserting battery pack shims 101 in parallel on the upper and lower sides between the end face 11a of the battery stack 11 and the inner wall surface 12a of the battery case 12, it is possible to absorb vibrations independently at the upper and lower parts of the contact portion 3b.

[0085] (Third embodiment) The first embodiment was configured to include a first space 6a that contacts both of the pair of contact portions 3a, 3b provided in the main body 2, and a second space 6b that is adjacent to the first space 6a and contacts both of the pair of contact portions. The third embodiment is characterized in that it further includes multiple throttle structures, providing four spaces.

[0086] FIG. 25 is a schematic diagram of a battery pack shim 201 according to the third embodiment. The third embodiment has a basic configuration in common with the first embodiment, so the common configuration will be assigned the same reference numerals and explanations will be omitted, and only the differences will be explained.

[0087] The battery pack shim 201 has a main body portion 2 and a fifth space formed in contact only with the abutment portion 3a provided within the main body portion 2, and the fifth space is divided into space 6e and space 6f.

[0088] The fifth space 6e is in contact with only the upper part of the contact portion 3a. The fifth space 6f is in contact with only the lower part of the contact portion 3a. The sixth space 6g is in communication with the fifth space 6e and in contact with only the upper part of the contact portion 3b. The seventh space 6h is in communication with the fifth space 6f and in contact with only the lower part of the contact portion 3b. The sixth space 6g and the seventh space 6h are not in communication with each other and are separated from each other.

[0089] The fifth space 6e, 6f, the sixth space 6g, and the seventh space 6h are filled with a fluid 7. It has an upper support part 46a extending from the upper end of the contact part 3a toward the contact part 3b (back side), and a lower support part 46b extending from the lower end of the contact part 3a toward the contact part 3b (back side).It also has an upper support part 46c extending from the center toward the contact part 3b (back side).All of the support parts 46a to 46c are fixed in position relative to the contact part 3a.

[0090] The tip of the support portion 46a and the support portion 46c are formed with protrusions 4e and 4f that are arranged facing each other, and a gap 5a that is a throttle structure is formed between the protrusions 4e and 4f. At the tip of the support portion 46c and the support portion 46b, protrusions 4g and 4h are formed which are arranged opposite to each other, and a gap 5b which is a throttle structure is formed between the protrusions 4g and 4h.

[0091] A protrusion 4i is formed at the tip of the support portion 46c on the contact portion 3a side, and a gap 5c having a throttle structure is formed between the protrusion 4i and the contact portion 3a. The configuration of the gaps 5a to 5c is the same as the gap 5 in the first embodiment, so a description thereof will be omitted.

[0092] The fifth space 6e and the space 6f are connected via a gap 5c. The fifth space 6e and the sixth space 6g are connected via a gap 5a. The fifth space 6f and the seventh space 6h are connected via a gap 5b.

[0093] (Operation of the third embodiment) FIG. 26 is a schematic diagram illustrating the operation of a battery pack shim 201 according to the third embodiment. Similar to the first embodiment shown in FIG. 6, when a resonant vibration is applied to the battery stack 11 of the in-vehicle battery pack 10, the battery stack 11 vibrates violently. As shown in FIG. 26, when the battery stack 11 presses the upper portion of the contact portion 3b, the sixth space 6f is compressed, reducing its volume, and the fluid 7 flows into the fifth space 6e through the gap 5a. At this time, the fluid 7 generates viscosity resistance in the gap 5a. The fluid 7 that flows into the space 6e similarly flows into the space 6g through the gap 5c. The fluid 7 that flows into the space 6g then flows into the seventh space 6h through the gap 5b. At this time, the seventh space 6h generates negative pressure because the abutment portion 3b is displaced in a direction that expands the seventh space 6h, and the seventh space 6h becomes a force that causes the fluid 7 to flow out of the space 6g of the fifth space.

[0094] The flow of the fluid 7 generates viscosity resistance in the gaps 5a, 5b, and 5c, which acts as a force to suppress the inclination of the contact portion 3a. Although not shown in the drawings, in the battery pack shim 201 of the third embodiment, the contact portion 3b may tilt in the opposite direction, as in the battery pack shim 1 of the first embodiment shown in Fig. 7. Even in such a case, the movement can be similarly suppressed by the viscous resistance of the fluid 7 due to the gaps 5a, 5b, and 5c. Therefore, the energy of large-amplitude resonance is consumed by the viscous resistance, and the strength of the battery stack 11 against vibration can be increased without increasing the mechanical rigidity of the battery pack 10.

[0095] (Modification of the third embodiment) In the third embodiment described above, the gaps 5a, 5b, and 5c generate flow path resistance for the fluid 7. However, for example, the gap 5c may be omitted, and the main body 2 may be formed by the gaps 5a and 5b. Conversely, the gaps 5a and 5b may be omitted, and only the gap 5c may be formed.

[0096] The battery pack shim 201 can be used with the front and back reversed. In the third embodiment, the throttle structure is formed by the gaps 5a, 5b, and 5c. However, for example, a partition separating the fifth space 6e and the space 6f may be provided, and the throttle structure may be formed by an orifice drilled in the partition.

[0097] (Effects of the third embodiment) (3-1) The sixth space 6g and the seventh space 6h can be separated and deformed independently, so that it is easy to accommodate a large displacement of the battery stack 11.

[0098] (3-2) The sixth space 6g, the fifth space 6e, the space 6f, and the seventh space 6h are all connected to each other, so that it is easy to deal with large displacements and vibrations can be effectively suppressed.

[0099] (Another example) The present invention has been described above using the first to third embodiments as examples, but it can also be implemented in the following configurations.

[0100] Although the battery pack shim 1 of the embodiment is generally a rectangular parallelepiped plate, the shape and dimensions thereof are not particularly limited. 22 is a schematic diagram of a battery pack shim 1 having modified protrusions 4a, 4b and a restricting portion 8. As shown in FIG. 8, the ridges 41, 41 of the pair of protrusions 4a, 4b may be formed so as to be offset in the vertical direction. In this case, even if the distance between the contact portions 3a, 3b changes, the gap 5 can be formed narrow.

[0101] In the embodiment, the pair of protrusions 4a, 4b are formed by filling the diaphragm 42 with the filler 45. However, the entire protrusions 4a, 4b may be formed of a solid material such as a solid resin. By forming the protrusions 4a, 4b from a solid material, the rigidity of the protrusions 4a, 4b can be increased.

[0102] In the embodiment, the battery pack shim 1 is formed by bonding together the various components, but these may be formed as a single unit. As shown in Figure 22, a restricting portion 8 may be provided that restricts vertical displacement of the pair of contact portions 3a, 3b by interfering with the vertical displacement. Generally, the contact portion 3a that contacts the battery case 12 is unlikely to become displaced, so one end is fixed to the contact portion 3a, and the other end of the contact portion 3b restricts the displacement when the contact portion 3b shifts upward.

[0103] Although not shown in the figures, a restricting portion 8 may be provided that restricts horizontal displacement by interfering with the pair of contact portions 3a, 3b. In this case as well, since the contact portion 3a that contacts the battery case 12 is unlikely to become displaced, one end is fixed to the contact portion 3a, and the other end of the contact portion 3b restricts the displacement when the contact portion 3a is displaced horizontally.

[0104] The shape, position, size and number of the regulating portion 8 are not limited, and it is sufficient if the members mutually protruding from both the contact portions 3a and 3b interfere with each other and regulate the shift when the contact portion 3b shifts upward or horizontally.

[0105] Fig. 23 is a schematic diagram showing the arrangement of a battery pack shim 1 in a battery pack 10. In the embodiment, the battery pack shim 1 is inserted between an end surface 11a of a battery stack 11 housed in a battery case 12 and an inner wall surface 12a of the battery case 12, but it may also be inserted on the opposite side. Furthermore, as shown in Fig. 23, the battery pack shim 1 may also be inserted between two battery stacks 11, 11.

[0106] Although the battery case 12 is made of an aluminum alloy in the above example, other metals such as stainless steel may also be used. Furthermore, in the case of alkaline electrolyte secondary batteries such as nickel-metal hydride batteries, even resin battery cases can be used.

[0107] Although the battery case 12 is exemplified as a rectangular plate, the battery case is not limited to this and may be a cubic battery case or a battery case with a partially curved surface as long as the present invention can be implemented.

[0108] The numerical values ​​and numerical ranges described in this embodiment are merely examples for explaining one embodiment, and the present invention is not limited thereto. These can be optimized by the person skilled in the art according to the configuration of the target secondary battery, etc.

[0109] The drawings and graphs are for the purpose of explaining the present embodiment, and the present invention is not limited thereto. Furthermore, the shape, dimensions, balance, number of layers, etc. of the battery pack 10 shown in the drawings are simplified or exaggerated for illustrative purposes, and other drawings and graphs do not limit the present invention.

[0110] The configurations disclosed in the respective embodiments can be combined with each other by those skilled in the art as long as no contradiction occurs. In addition, it goes without saying that the present invention can be implemented by those skilled in the art by adding, deleting or modifying its configuration, provided that the addition, deletion or modification does not deviate from the scope of the claims. [Explanation of symbols]

[0111] SIM for 1, 101, 201... (battery pack) 2...Main body 21...Upper 22...Lower 23...Left side 24...Right side 25...Injection hole 3 (Front 3a, back 3b)…Contact part 4(4a~4i)...Protruding part 41...Ridge 41a, 41b, 41c... points 42...diaphragm 43...Folding section 43a...Fold 1 (mountain fold) 43b…Fold 2 (valley fold) 43c...Fold 3 (mountain fold) 44...End 45...Filling 46(46a~46c)...Support part 5...Gap (aperture structure, slit) 6...Space (1st to 8th spaces 6a-h) 7...Fluid 8. Regulatory Department 10...Battery pack 11...Battery stack 11a, 11b...end face 11c...Restraining member 12...Battery case 12a, 12b...inner wall surface 13...Battery cell 14...End plate 15...Injection device 15a...Pressure injection section 15b…Injection pipe AP…Aperture G...Gap D, D1, D2...Thickness L1…Curve L2…Curve

Claims

1. A battery pack shim that adjusts the size of a gap between a battery case and a battery stack that contains a plurality of battery cells stacked in a battery case, a contact portion consisting of a pair of plate-shaped members that contacts the inner wall of the battery stack or the battery case; a main body portion provided between the pair of contact portions and having an airtight space made of a flexible material; a first space provided in the main body portion and in contact with both of the pair of abutment portions; and a second space adjacent to the first space and in contact with both of the pair of abutment portions. a fluid filled in the first space and the second space, the first space and the second space are in communication with each other via a throttle structure, A shim for a battery pack, characterized in that the fluid filled in the first space and the second space is configured to be movable between adjacent spaces via the throttle structure in response to force applied to the abutment portion.

2. 2. The shim for a battery pack according to claim 1, wherein the throttle structure is formed by a gap between a pair of protrusions that protrude from the pair of abutting portions in opposing relation to each other.

3. 3. The shim for a battery pack according to claim 2, wherein the gap between the pair of protrusions is formed as a slit extending in a horizontal direction.

4. 3. The shim for a battery pack according to claim 2, wherein the pair of protrusions have horizontal linear ridges.

5. 5. The battery pack shim according to claim 4, wherein the ridges of the pair of protrusions are offset from each other in the vertical direction.

6. 3. The shim for a battery pack according to claim 2, wherein the pair of protrusions have a triangular vertical cross section.

7. 3. The shim for a battery pack according to claim 2, wherein the pair of protrusions are formed of a diaphragm filled with a liquid.

8. 8. The shim for a battery pack according to claim 7, wherein the dividing membrane of the protruding portion is made of a flexible resin, and the dividing membrane has a folding portion formed thereon that can expand and contract horizontally in accordance with the expansion and contraction of the main body portion.

9. 3. The shim for a battery pack according to claim 2, wherein the pair of protrusions are formed of a solid material.

10. 2. The shim for a battery pack according to claim 1, wherein the fluid filled in the main body has a viscosity of 1 to 10 Pa / s.

11. A shim for a battery pack as described in any one of claims 1 to 10, characterized in that the main body portion is provided with an injection hole that allows the fluid to be injected from the outside and seals the injected fluid.

12. The shim for a battery pack according to any one of claims 1 to 10, further comprising a restricting portion that restricts misalignment by interfering with vertical and horizontal misalignment of the pair of contact portions.

13. 2. The shim for a battery pack according to claim 1, wherein the throttle structure is formed by an orifice provided in a partition that separates the first space from the second space.

14. A battery pack shim that adjusts the size of a gap between a battery case and a battery stack, the battery stack being formed by stacking a plurality of battery cells in a battery case and accommodating the battery stack from above, a contact portion consisting of a pair of plate-shaped members that contacts the inner wall of the battery stack or the battery case; a main body portion provided between the pair of contact portions and having an airtight space made of a flexible material; a third space formed in contact with one of the pair of abutment portions provided in the main body portion; and a fourth space communicating with the third space and formed in contact with the other of the pair of abutment portions; a fluid filled in the third space and the fourth space, the third space and the fourth space are communicated with each other via a throttle structure, the throttle structure is fixed in position to one of the pair of abutment portions, A shim for a battery pack, characterized in that the fluid filled in the third space and the fourth space is configured to be movable between adjacent spaces via the throttle structure in response to force applied to the abutment portion.

15. A battery pack shim that adjusts the size of a gap between a battery case and a battery stack, the battery stack being formed by stacking a plurality of battery cells in a battery case and accommodating the battery stack from above, a contact portion consisting of a pair of plate-shaped members that contacts the inner wall of the battery stack or the battery case; a main body portion provided between the pair of contact portions and having an airtight space made of a flexible material; a fifth space formed in contact with one of the pair of abutment portions provided in the main body portion; a sixth space communicating with the fifth space and formed in contact with the other of the pair of contact portions; a seventh space adjacent to the sixth space with a gap therebetween, communicating with the fifth space, and formed in contact with the other of the pair of contact portions; a fluid filled in the fifth space, the sixth space, and the seventh space; the fifth space and the sixth space, and the fifth space and the seventh space are communicated with each other via a throttle structure formed in a support portion extending from a central portion of one of the pair of contact portions through the main body portion to the other of the pair of contact portions, the throttle structure is fixed in position to one of the pair of abutment portions, A shim for a battery pack, characterized in that the fluid filled in the fifth space and the sixth space, and the fifth space and the seventh space, is configured to be movable between adjacent spaces via the throttle structure in response to force applied to the abutment portion.

16. The fifth space is further divided into a portion communicating with the sixth space and a portion communicating with the seventh space by a throttle structure, 16. The shim for a battery pack according to claim 15, characterized in that the fluid filled in the portion communicating with the sixth space and the portion communicating with the seventh space is configured to be movable between adjacent spaces via the throttle structure in response to a force applied to the abutment portion.

17. a restraining step of pressing and restraining a battery stack formed by stacking a plurality of battery cells in a stacking direction; a battery stack insertion step of inserting the battery stack in a restrained state into a battery case; a shim insertion process for inserting a battery pack shim into a space between an end face of the battery stack in a stacking direction and an inner wall surface of the battery case opposite the end face, the battery pack shim comprising: a pair of abutment portions made of a pair of plate-like members abutting against the battery stack or an inner wall of the battery case; a main body portion provided between the pair of abutment portions and having a space made of a flexible material and airtightly configured to be filled with a fluid; a first space provided in the main body portion and abutting both of the pair of abutment portions; a second space adjacent to the first space and abutting both of the pair of abutment portions; the first space and the second space; the first space and the second space being communicated with each other via an aperture structure, and the fluid filled in the first space and the second space being movable between the adjacent spaces via the aperture structure in response to a force applied to the abutment portions; filling the fluid into the fluid-filled space; A method for manufacturing a battery pack, comprising:

18. The shim insertion step includes a shim compression step of compressing the battery pack shim in a stacking direction. inserting the compressed battery pack shim into a space between an end face of the battery stack in a stacking direction and an inner wall surface of the battery case facing the end face; 18. The method for manufacturing a battery pack according to claim 17, wherein the compression is released after insertion to bring the end face of the battery stack in the stacking direction into pressure contact with the inner wall surface of the battery case that faces the end face.

19. The shim insertion step includes: inserting the battery pack shim into a space between an end face of the battery stack in a stacking direction and an inner wall surface of the battery case facing the end face; 18. The method for manufacturing a battery pack according to claim 17, wherein the fluid is injected into the main body after insertion, thereby pressing the end face of the battery stack in the stacking direction against the inner wall surface of the battery case facing the end face.

20. A battery pack comprising the battery pack shim according to any one of claims 1, 14 and 15, wherein a battery stack formed by stacking a plurality of battery cells is housed in a battery case, and a dimension of a gap between the battery case and the battery stack is adjusted by the battery pack shim, a battery stack of the battery pack, wherein the battery cells directly abut the battery pack shims on a surface facing the battery pack shims, and the battery cells abut the inner wall of the battery case via end plates on a surface different from the surface facing the battery pack shims.

Images