Method of manufacturing a battery pack

Abstract

This invention provides a method for manufacturing a battery pack. Even when there is a height difference on the bottom surface of the battery casing, the bottom surface of the battery module can be in large-area contact with the thermally conductive material when the liquid thermally conductive material applied to the bottom surface and used to fix the battery module solidifies. The method involves measuring the shape, including the height, of the battery support surface of the battery casing, which houses a battery module having multiple battery cells stacked along a predetermined direction. An information code containing information representing the shape of the battery support surface is created and set on the battery casing. Based on the information representing the shape of the battery support surface obtained by reading the information code, a liquid thermally conductive material with adhesive function is applied to the battery support surface. The amount of thermally conductive material applied to multiple locations arranged along the predetermined direction on the battery support surface increases as the height of the location decreases.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a battery pack. Background Technology

[0002] The following technology is disclosed in Patent Document 1: a fluid thermally conductive material is coated on the bottom plate of the battery casing, and after the battery module is placed on the thermally conductive material, the thermally conductive material is cured, thereby fixing the battery module to the battery casing.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-156003 Summary of the Invention

[0004] During the manufacturing of the battery casing, deformation sometimes occurs in the base plate. That is, the area on the base plate used to fix the battery module is not perfectly flat, and sometimes there are local height differences. In this case, if the thermally conductive material of the same thickness (amount) is applied to the entire area on the base plate used to fix the battery module, there is a risk that a part of the lower surface of the battery module will not be in contact with the thermally conductive material when the thermally conductive material cures.

[0005] In view of the above facts, the present invention aims to provide a method for manufacturing a battery pack that, even when there is a height difference on the bottom surface of the battery casing, enables the bottom surface of the battery module to make large-area contact with the thermally conductive material when the liquid thermally conductive material coated on the bottom surface and used to fix the battery module is cured.

[0006] The method for manufacturing a battery pack according to the first method includes the following steps: a measurement step, measuring the shape of a battery support surface, including its height, wherein the battery support surface is a portion of the bottom surface of a battery housing that accommodates a battery module having multiple battery cells stacked along a predetermined direction and extends along the predetermined direction; an information code creation step, creating an information code containing information representing the shape based on the measured shape of the battery support surface; an information code assignment step, setting the created information code on the battery housing; a reading step, reading in the information code; a coating step, coating a liquid thermally conductive material with adhesive function onto the battery support surface based on the information representing the shape of the battery support surface obtained by reading in the information code, such that the amount of the thermally conductive material coated on multiple locations arranged along the predetermined direction on the battery support surface increases as the height of the locations decreases; and a battery module placement step, placing the bottom surface of the battery module on the upper surface of the thermally conductive material.

[0007] Invention Effects

[0008] As explained above, the battery pack manufacturing method of the present invention has the following excellent effects: even when there is a height difference on the bottom surface of the battery casing, when the liquid thermally conductive material coated on the bottom surface and used to fix the battery module is cured, the bottom surface of the battery module can be in contact with the thermally conductive material over a large area. Attached Figure Description

[0009] Figure 1 This is a perspective view of the manufacturing apparatus for the battery pack manufacturing method according to the embodiment, viewed from above the lower housing.

[0010] Figure 2 This is a top view of the battery casing.

[0011] Figure 3 It is along Figure 2 A schematic cross-sectional view with 3-3 arrows.

[0012] Figure 4 It is a chart showing the vertical distance between the ranging unit and various parts of the battery support surface.

[0013] Figure 5 This is a schematic cross-sectional view of a battery module positioned directly above the thermally conductive material coated in the first setting area.

[0014] Figure 6 This is a schematic cross-sectional view of a battery module placed on a thermally conductive material coated in the first setting area.

[0015] Figure 7 This is a schematic top view of the battery support surface and a portion of the thermally conductive material when a battery module is placed on the thermally conductive material.

[0016] Figure 8 This is a schematic cross-sectional view of a battery module positioned directly above the thermally conductive material coated in the second setting area.

[0017] Figure 9 This is a schematic cross-sectional view of a battery module placed on a thermally conductive material coated in the second setting area.

[0018] Figure 10 This is a top view of the lower casing and the four battery modules.

[0019] Figure 11 It is a flowchart representing the processing executed by the CPU of the control device.

[0020] Figure 12 It is equivalent to a comparative example. Figure 5 A schematic cross-sectional view.

[0021] Figure 13 It is equivalent to a comparative example. Figure 6A schematic cross-sectional view.

[0022] Figure 14 This is a schematic top view of the battery support surface and a portion of the thermally conductive material when a battery module is placed on the thermally conductive material of the comparative example. Detailed Implementation

[0023] Hereinafter, the manufacturing method of the battery pack according to the embodiment will be described with reference to the accompanying drawings. In addition, the arrows UP, FR, and LH in each figure represent the upper side in the vertical direction, the front side in the front-back direction, and the left side in the horizontal direction, respectively.

[0024] The battery pack manufacturing method of this embodiment utilizes Figure 1 The manufacturing apparatus 10 shown is used to perform the operation. The manufacturing apparatus 10 includes a support platform 12, a cleaning and ranging device 14, a first moving mechanism 16, a coating device 18, a second moving mechanism 20, a discharge control mechanism 21, a camera 22, a transport reversing device 24, a code creation and assignment device 26, and a control device 30.

[0025] A cleaning and ranging device 14, a coating device 18, and a camera 22 are installed above a support platform 12 fixed to the ground.

[0026] The cleaning distance measuring device 14 moves in the space above the support platform 12. The cleaning distance measuring device 14 is connected to the first moving mechanism 16 and moves linearly in the front-back and left-right directions by the driving force of the first moving mechanism 16. The vertical position of the cleaning distance measuring device 14 remains unchanged. The first moving mechanism 16, for example, is equipped with an electric motor as a drive source. A surface treatment section and a distance measuring section are provided at the lower end of the cleaning distance measuring device 14. The surface treatment section has a surface treatment function to perform surface treatment on the lower housing 40 (described later as the object located below). For example, the surface treatment section performs surface treatment on the lower housing 40 by shot peening or plasma treatment. The distance measuring section is, for example, optical, and measures the vertical distance between itself and the surface of the lower housing 40 (the battery support surface 50 described later). Furthermore, the vertical distance mentioned below refers to the vertical distance from the distance measuring section.

[0027] The coating apparatus 18 moves in the space above the support platform 12. The coating apparatus 18 is connected to a second moving mechanism 20 and moves linearly in the front-back and left-right directions by the driving force of the second moving mechanism 20. The second moving mechanism 20, for example, has an electric motor as a drive source. The coating apparatus 18 is connected to a thermally conductive material storage section (not shown). A dispensing section, serving as an opening, is provided at the lower end of the coating apparatus 18. The coating apparatus 18 can dispense liquid (viscous paste-like) thermally conductive material supplied from the thermally conductive material storage section and acting as an adhesive, downwards from the dispensing section under the control of the dispensing control mechanism 21. The dispensing control mechanism 21 can adjust the dispensing pressure of the thermally conductive material dispensed from the dispensing section.

[0028] The camera 22 is positioned above the support platform 12 and is capable of photographing a subject located below it. For example, the camera 22 can photograph the code-forming body 60, which will be described later.

[0029] The conveying reversing device 24 can place the lower housing 40, which is stored in a different position from the support platform 12, on the upper surface of the support platform 12, or move the lower housing 40 placed on the upper surface of the support platform 12 to another position, or reverse the vertical direction of the lower housing 40 placed on the upper surface of the support platform 12.

[0030] The code creation device 26 has the function of creating a code form 60 based on the ranging data described later, and mounting the created code form 60 on the upper surface of the junction box 59 described later.

[0031] The cleaning ranging device 14, the first moving mechanism 16, the second moving mechanism 20, the ejection control mechanism 21, the camera 22, the conveying reversal device 24, and the code creation and assignment device 26 are connected to the control device 30. The control device 30 is composed of a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), a storage device, communication I / F, and input / output I / F. The CPU, ROM, RAM, storage device, communication I / F, and input / output I / F are interconnected and can communicate with each other via an internal bus.

[0032] The CPU is the central processing unit, executing various programs and controlling various components. The CPU reads programs from ROM or storage devices and uses RAM as its working area to execute them. The CPU performs control and various calculations according to the programs recorded in ROM or storage devices. ROM stores various programs and data. RAM serves as the working area, temporarily storing programs or data. Storage devices, such as HDDs or SSDs, store various programs and data. Communication I / F is the interface used for communication with different control devices. Input / output I / F is the interface used for communication with various devices.

[0033] The control device 30 has a functional structure comprising a transport control unit, a surface treatment ranging control unit, a shape calculation unit, a correction calculation unit, an information code creation and assignment unit, a reading unit, and a coating amount control unit. The transport control unit, surface treatment ranging control unit, shape calculation unit, correction calculation unit, information code creation and assignment unit, reading unit, and coating amount control unit are implemented by the CPU reading and executing programs stored in ROM.

[0034] The conveying control unit has the function of controlling the conveying reversing device 24. As described above, the conveying reversing device 24 controlled by the conveying control unit can, for example, convey the integrated lower housing 40 and junction box 59, which are located at a different position from the support platform 12, to the upper surface of the support platform 12.

[0035] The lower housing 40 is a one-piece molded resin product with a generally quadrilateral planar shape. The upper surface of the lower housing 40 is open. The lower housing 40 has a quadrilateral base plate 41 and an annular wall 42 whose lower end connects to the outer periphery of the base plate 41. Furthermore, flanges 42A are respectively provided on the left and right sides of the upper end of the annular wall 42. A rib 43 extending in the left-right direction is provided at the center of the base plate 41 in the front-rear direction. Therefore, the mechanical strength of the center of the base plate 41 in the front-rear direction is higher than that of other parts of the base plate 41. In other words, the mechanical strength of the parts other than the center of the base plate 41 is lower than that of the center.

[0036] like Figure 2 As shown, a first mounting area 44 and a second mounting area 45, which are rectangular and extend in the left-right direction when viewed from above, are formed in the area of ​​the base plate portion 41 further forward than the rib 43. A third mounting area 46 and a fourth mounting area 47, which are rectangular and extend in the left-right direction when viewed from above, are formed in the area of ​​the base plate portion 41 further rear than the rib 43.

[0037] like Figure 1As shown, the first mounting area 44, the second mounting area 45, the third mounting area 46, and the fourth mounting area 47 are positioned one level above the peripheral portion, and their upper surfaces are formed by battery support surfaces 50. The planar shape of each battery support surface 50 in the first mounting area 44, the second mounting area 45, the third mounting area 46, and the fourth mounting area 47 is approximately rectangular, and the width (front and rear dimensions) of each battery support surface 50 is substantially the same. Figure 1 , Figure 2 and Figure 5 The symbol 51 depicted in the figure represents the right end of each battery support surface 50, and the symbol 52 represents the left end of each battery support surface 50.

[0038] The surface treatment ranging control unit has the function of controlling the cleaning ranging device 14 and the first moving mechanism 16. For example, Figure 1 and Figure 2 As shown, assuming that the lower housing 40 and junction box 59 are placed on the support platform 12 by means of the action of the conveying reversing device 24, so that the base plate 41 contacts the upper surface of the support platform 12.

[0039] like Figure 2 As shown, the four directions (regions) of the support platform 12 that extend horizontally and are arranged sequentially in a top-down view are referred to as column 1 L1, column 2 L2, column 3 L3, and column 4 L4. In a top-down view, column 1 L1 overlaps with the first setting region 44, column 2 L2 overlaps with the second setting region 45, column 3 L3 overlaps with the third setting region 46, and column 4 L4 overlaps with the fourth setting region 47. Furthermore, column 1 L1, column 2 L2, column 3 L3, and column 4 L4 each have three portions arranged horizontally. That is, as... Figure 2 As shown, columns L1 (1st), L2 (2nd), L3 (3rd), and L4 (4th) each have a standby area A1, a processing execution area A2, and an end area A3, respectively. In top view, the processing execution area A2 aligns with each battery support surface 50. In top view, the standby area A1 aligns with the portion located further to the right of the right end 51 of each battery support surface 50 in the base plate 41. Furthermore, in top view, the end area A3 aligns with the portion located further to the left of the left end 52 of each battery support surface 50 in the base plate 41.

[0040] The first moving mechanism 16, controlled by the surface treatment ranging control unit, enables the cleaning ranging device 14 to move from... Figure 2The sweeping distance measuring device 14 moves from position SP1 to position EP4, and then returns to position SP1. More specifically, the sweeping distance measuring device 14 first moves to the left from position SP1, which is the standby area A1 of the first column L1, to position EP1, which is the end area A3 of the first column L1. After that, the sweeping distance measuring device 14 temporarily returns to position SP1, then moves to position SP2, which is the standby area A1 of the second column L2, and moves to the left from position SP2, to position EP2, which is the end area A3 of the second column L2. After that, the sweeping distance measuring device 14 temporarily returns to position SP2, then moves to position SP3, which is the standby area A1 of the third column L3, and moves to the left from position SP3, to position EP3, which is the end area A3 of the third column L3. Afterwards, the cleaning ranging device 14 temporarily returns to position SP3, then moves to position SP4, which is the standby area A1 of the 4th column L4. From position SP4, it moves to the left, to position EP4, which is the end area A3 of the 4th column L4. Then, the cleaning ranging device 14 moves back to position SP1 from position EP4. Hereinafter, the movement trajectory of the cleaning ranging device 14 from position SP1, position EP1, position SP2, position EP2, position SP3, position EP3, position SP4, and back to position SP1 will be referred to as the set path. Additionally, as described later, the coating device 18 can also move along the set path. Furthermore, when the cleaning ranging device 14 moves along the set path, it is assumed to move in a completely horizontal direction.

[0041] While the cleaning ranging device 14 moves along the set path, the surface treatment unit performs surface treatment on the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47 of the lower housing 40. As a result, the upper surfaces of the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47 are surface treated, and each upper surface is cleaned.

[0042] During the movement of the cleaning ranging device 14 along the set path, the ranging unit measures the vertical distance between itself and each battery support surface 50. Hereinafter, the data obtained by the cleaning ranging device 14 (ranging unit) related to the vertical distance between each battery support surface 50 and the ranging unit will be referred to as ranging data.

[0043] The shape calculation unit calculates the shapes of the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47 based on the ranging data acquired by the cleaning ranging device 14. In other words, the shape calculation unit generates... Figure 4The shape line DL is shown as a single-dot dash. Furthermore, this shape line DL is related to the battery support surface 50 of the second mounting region 45, and the shape line DL is generated for the first mounting region 44, the second mounting region 45, the third mounting region 46, and the fourth mounting region 47 respectively. For example... Figure 4 It is clearly understood that the vertical distance between the battery support surface 50 in the second setting area 45 and the cleaning ranging device 14 (ranging unit) is not constant, but varies depending on the horizontal position of the battery support surface 50. That is, as Figure 8 As shown, the battery support surface 50 of the second setting area 45 is not a completely flat surface but a curved surface. In other words, the height of the battery support surface 50 is not constant.

[0044] Correcting the arithmetic unit Figure 3 The cleaning distance measuring device 14 and the right end 51, i.e., the vertical distance L51, and the cleaning distance measuring device 14 and the left end 52, i.e., the vertical distance L52, are used to correct the shape line DL. In other words, the correction calculation unit executes the horizontal line HL (reference) extending in the left-right direction based on the lower housing 40 (battery support surface 50) in the front view. Figure 3 The tilt of the shape line DL is used to correct the shape line correction process. For example, Figure 3 The left end 52 of the battery support surface 50 shown is located lower than the right end 51. That is, Figure 3 The lower housing 40 is inclined relative to the horizontal line HL. Let the straight line CL passing through the right end 51 and left end 52 in this case be inclined at an angle θ relative to the horizontal line HL. In this case, the correction calculation unit makes... Figure 4 The shape line DL is rotated clockwise by an angle θ around the left end (the end corresponding to the right end 51). The corrected shape is thus... Figure 3 The corrected shape line CDL is shown in solid line. The correction calculation unit performs the correction process on the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47.

[0045] Furthermore, the correction calculation unit identifies each battery support surface 50 (processing execution area A2) as multiple segmented regions. That is, the correction calculation unit identifies the battery support surface 50 as eight segmented regions arranged in the left-right direction. Specifically, the correction calculation unit identifies each battery support surface 50 sequentially from the right side as eight regions of the same size: 1, 2, 3... region 8. That is, the correction calculation unit identifies a total of 32 parts provided in the lower housing 40. Hereinafter, these 32 regions will be referred to as processing unit parts. Furthermore, each processing unit part will be represented by combining columns and regions. That is, for example, the processing unit part corresponding to region 1 of the battery support surface 50 in the first setting region 44 (first column L1) is called "processing unit part L1-1", the processing unit part corresponding to region 5 in the second setting region 45 (second column L2) is called "processing unit part L2-5", the processing unit part corresponding to region 7 in the third setting region 46 (third column L3) is called "processing unit part L3-7", and the processing unit part corresponding to region 8 in the fourth setting region 47 (fourth column L4) is called "processing unit part L4-8".

[0046] Furthermore, the correction calculation unit averages the vertical distance represented by the correction shape line CDL across eight processing unit areas. That is, the correction calculation unit calculates the average vertical distance of the entire area of ​​each processing unit area. For example, ... Figure 4 As shown, the correction shape line CDL of the second setting area 45 is changed to an 8-bar graph. That is, within the range of each processing unit, the correction calculation unit considers the vertical distance between the cleaning ranging device 14 and the battery support surface 50 to be constant. In other words, within the range of each processing unit, the correction calculation unit considers the height of each processing unit to be constant.

[0047] The information code creation and assignment unit controls the code creation and assignment device 26. The code creation and assignment device 26, controlled by the information code creation and assignment unit, generates information code 61 (see reference) representing data that establishes a correlation between the average value of each processing unit portion of the first setting region 44, second setting region 45, third setting region 46, and fourth setting region 47 obtained by the correction calculation unit and each processing unit portion. Figure 2 The generated information code 61 is set in the code forming body 60 (see reference). Figure 2 The surface of the information code 61 in this embodiment includes at least one of a one-dimensional code and a two-dimensional code. Furthermore, the two-dimensional code includes, for example, a QR code (registered trademark). The code forming body 60 in this embodiment is a generally square, thin-walled component with an adhesive coated on its back side.

[0048] Moreover, such as Figure 2As shown, the information code creation and assignment unit uses an adhesive to fix the back of the code forming body 60 to the upper surface of the junction box 59.

[0049] The reading unit has the function of reading image data including the information code 61 (code forming body 60) acquired by the camera 22. That is, the reading unit identifies the average value of each processing unit part of the first setting area 44, the second setting area 45, the third setting area 46 and the fourth setting area 47 represented by the information code 61.

[0050] The coating amount control unit controls the coating apparatus 18 (discharge control mechanism 21) based on the average value of each processing unit portion in the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47 identified by the reading unit. That is, the coating amount control unit controls the discharge control mechanism 21 so that the larger the average value of the vertical distance, the greater the discharge pressure of the thermally conductive material based on the coating apparatus 18, and the smaller the average value, the lower the discharge pressure of the thermally conductive material based on the coating apparatus 18. Therefore, a large amount of thermally conductive material is coated on the processing unit portions located at lower positions (larger average value), and a small amount of thermally conductive material is coated on the processing unit portions located at higher positions (smaller average value).

[0051] Next, the processing executed by the CPU of the control device 30 will be explained. The CPU repeats the process every time a predetermined time has elapsed. Figure 11 The flowchart shown illustrates the processing. Alternatively, the lower housing 40 and junction box 59 are placed on the support platform 12 in the following manner: the base plate 41 contacts the upper surface of the support platform 12.

[0052] In step S10 (hereinafter, the characters of the steps are omitted), the CPU identifies the column count value. Additionally, the initial value of the column count value is "1".

[0053] After the CPU finishes processing in S10, it enters S11, causing the cleaning ranging device 14 and the first moving mechanism 16 to perform surface processing and ranging processing on the setting area corresponding to the column count value. When the column count value = 1, the cleaning ranging device 14 processes the first setting area 44; when the column count value = 2, the cleaning ranging device 14 processes the second setting area 45; when the column count value = 3, the cleaning ranging device 14 processes the third setting area 46; and when the column count value = 4, the cleaning ranging device 14 processes the fourth setting area 47.

[0054] The following assumes the column count value is 1. In this case, the cleaning ranging device 14 moves from position SP1 to position EP1 along the set path, and performs surface processing and ranging processing on the first set area 44 during this period. The CPU, after completing the processing of S11, causes the cleaning ranging device 14 to return to position SP1 along the set path.

[0055] After completing the processing in S11, the CPU proceeds to S12 to calculate the shape of the battery support surface 50 in the first setting region 44. That is, the CPU generates the shape line DL.

[0056] The CPU, having completed processing in S12, proceeds to S13 to perform correction processing on the shape line DL acquired in S12. That is, the CPU generates a corrected shape line CDL. All processing unit portions included in the battery support surface 50 of the first setting region 44 are at the same vertical distance (height) from the ranging unit. That is, as... Figure 5 and Figure 6 As shown, the battery support surface 50 of the first setting area 44 is a plane orthogonal to the vertical direction.

[0057] After the CPU finishes processing S13, it proceeds to S14 to determine whether the column count value is 4.

[0058] Since the column count is 1, the CPU determines "No" in S14 and proceeds to S15. Therefore, the column count becomes "2". Afterward, the CPU temporarily terminates the processing of this flowchart.

[0059] Next, the CPU executes processes S10 to S14 again. In this case, the column count is "2". In S11, the cleaning ranging device 14 moves along the set path from position SP1 to position SP2 and then to position EP2, during which time surface treatment and ranging processing are performed on the battery support surface 50 of the second setting area 45. The CPU, having finished processing S11, causes the cleaning ranging device 14 to return to position SP2 along the set path. Furthermore, in processing S12, the CPU generates the shape line DL of the battery support surface 50 of the second setting area 45. In this case, the shape line DL is... Figure 4 The shape shown is line DL.

[0060] Furthermore, in S13, the CPU generates a corrected shape line CDL, and then averages the vertical distances of the eight processing unit locations based on the corrected shape line CDL. That is, the CPU generates... Figure 4 The chart shows 8 bars.

[0061] After completing S13, the CPU proceeds to S14 to determine if the column count value is 4. In this case, since the column count value is 2, the CPU determines "No" in S14 and proceeds to S15. Therefore, the column count value becomes "3". Afterward, the CPU temporarily terminates the processing of this flowchart.

[0062] Next, the CPU processes the third setting area 46 in steps S10 to S14. During this time, the cleaning ranging device 14 moves from position SP2 to position SP3 and then to position EP3 along the set path in step S11. During this period, surface treatment and ranging processing are performed on the battery support surface 50 of the third setting area 46. After completing step S11, the CPU causes the cleaning ranging device 14 to return to position SP3 along the set path.

[0063] Next, the CPU performs processing steps S10 to S14 on the fourth setting area 47. During this time, the cleaning ranging device 14 moves from position SP3 to position SP4 and then to position EP4 along the set path in S11. During this period, surface treatment and ranging processing are performed on the battery support surface 50 of the fourth setting area 47. After completing processing in S11, the CPU causes the cleaning ranging device 14 to return to position SP1 along the set path.

[0064] In addition, for convenience, it is assumed that the vertical distance between all processing unit portions included in each battery support surface 50 of the third setting area 46 and the fourth setting area 47 is the same.

[0065] After the CPU processes the fourth setting area 47 in S13, it determines "Yes" in S14 and proceeds to S16.

[0066] In S16, the CPU control code creation and assignment device 26 generates information code 61 representing data that establishes a correlation between the average vertical distance of each processing unit portion in the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47 and each processing unit portion, and sets the generated information code 61 on the surface of the code forming body 60. Furthermore, the code creation and assignment device 26 uses an adhesive to attach the manufactured code forming body 60 to the upper surface of the junction box 59.

[0067] After completing process S16, the CPU proceeds to S17 and controls the transport reversal device 24. The transport reversal device 24 reverses the vertical direction of the lower housing 40 placed on the support platform 12, positioning the lower housing 40 on the support platform 12 such that the base plate portion 41 is located at the upper end of the lower housing 40. Furthermore, in S17, the CPU controls the cooler mounting device (not shown). The cooler mounting device applies a liquid adhesive, i.e., a thermally conductive material (not shown), to the base plate portion 41, and places the cooler (not shown) on this thermally conductive material.

[0068] The CPU, having completed processing S17, proceeds to S18 and controls the second moving mechanism 20 and the dispensing control mechanism 21. The coating device 18, controlled by the second moving mechanism 20, moves from its initial position (position SP1) to position EP1 along a set path at a constant speed. During this time, the coating device 18, controlled by the dispensing control mechanism 21, dispenses thermally conductive material onto the battery support surface 50 of the first setting area 44. At this time, the coating device 18 adjusts the dispensing pressure of the thermally conductive material based on the average value of each processing unit located directly below. However, as described above, the vertical distance of the entire battery support surface 50 of the first setting area 44 is the same. That is, the average vertical distance of all processing unit locations included in the battery support surface 50 of the first setting area 44 is the same. Therefore, the coating device 18 dispenses thermally conductive material 70 onto all processing unit locations included in the battery support surface 50 of the first setting area 44 with the same dispensing pressure. Therefore, as... Figure 5 As shown, the thickness (vertical dimension) of the thermally conductive material 70 coated on the battery support surface 50 in the first setting region 44 is substantially the same along its entire length (the entire left-right direction). Furthermore, as... Figure 7 As shown by the dashed line, the width (front and rear dimensions) of the thermally conductive material 70 is smaller than the width of the battery support surface 50.

[0069] Next, in S18, the CPU controls the second moving mechanism 20 to move the coating device 18 from position SP1 to position SP2, and then further moves it along a set path at a constant speed to position EP2. During this period, the coating device 18, controlled by the dispensing control mechanism 21, dispenses thermally conductive material onto the battery support surface 50 of the second setting area 45. At this time, the coating device 18 adjusts the dispensing amount based on the average vertical distance of each processing unit portion located directly below. As described above, the vertical distances of each processing unit portion included in the battery support surface 50 of the second setting area 45 differ. That is, as... Figure 4As shown, there are differences in the average vertical distances between the processing unit portions included in the battery support surface 50 of the second setting region 45. Therefore, the coating apparatus 18 increases, for example, the discharge pressure when dispensing thermally conductive material to the processing unit portion L2-2, so that it is greater than the discharge pressure when dispensing thermally conductive material to the processing unit portion L2-1 of the battery support surface 50. Furthermore, the coating apparatus 18 increases the discharge pressure when dispensing thermally conductive material to the processing unit portion L2-5, so that it is greater than the discharge pressure when dispensing to other processing unit portions. Therefore, as... Figure 8 As shown, the thickness of the thermally conductive material 71 coated on the battery support surface 50 in the second installation region 45 varies depending on the processing unit location. Additionally, as... Figure 7 As shown by the dashed line, the width (front and rear dimensions) of the thermally conductive material 71 is smaller than the width of the battery support surface 50.

[0070] Next, in S18, the CPU controls the second moving mechanism 20 to move the coating device 18 from position SP2 to position SP3, and then further moves it along a set path at a constant speed to position EP3. During this time, the coating device 18 dispenses thermally conductive material onto the battery support surface 50 of the third setting region 46. Also in S18, the CPU controls the second moving mechanism 20 to move the coating device 18 from position SP3 to position SP4, and then further moves it along a set path at a constant speed to position EP4. During this time, the coating device 18 dispenses thermally conductive material onto the battery support surface 50 of the fourth setting region 47. Although not shown in the figure, the thickness of the thermally conductive material coated on the battery support surface 50 of the third setting region 46 and the battery support surface 50 of the fourth setting region 47 is substantially the same along its entire length, similar to that of the first setting region 44. Furthermore, the width of the thermally conductive material coated on the third setting region 46 and the fourth setting region 47 is also smaller than the width of the battery support surface 50.

[0071] After the CPU finishes processing S18, it enters S19 and controls the battery module setting device (not shown). The battery module setting device holds one of the multiple battery modules 75 stored in a storage device (not shown) located near the support platform 12.

[0072] like Figure 5As shown, the battery module 75 includes a battery stack 76 extending in the left-right direction, two lower supports 78, and two upper supports 81. The battery stack 76 includes: a plurality of battery cells (not shown) arranged in the left-right direction (a predetermined direction); a plurality of insulating members (spacers, not shown) located between adjacent battery cells; a pair of left and right end plates 77 that clamp all battery cells and insulating members in the left-right direction; and constraint members (not shown) connected to the left and right end plates 77 to pull the end plates 77 closer together. Furthermore, the bottom surface of the battery stack 76 in this embodiment is substantially composed of a single plane. That is, there is substantially no height difference between the bottom surfaces of each battery cell, each insulating member, and each end plate 77. Moreover, lower supports 78 and upper supports 81 are fixed to each end plate 77. Mounting portions 79 constituting the outer ends of the lower supports 78 and mounting portions 82 constituting the outer ends of the upper supports 81 overlap and are fixed to each other in the vertical direction.

[0073] like Figure 5 As shown, in S19, the battery module mounting device positions one battery module 75 directly above the battery support surface 50 of the first mounting area 44. Furthermore, the battery module mounting device moves the battery module 75 downwards, as... Figure 6 As shown, the mounting portion 79 of each lower bracket 78 is placed on the upper surface of the corresponding flange 42A. Consequently, the thermally conductive material 70 is clamped by the lower surface of the battery stack 76 and the battery support surface 50 of the first mounting region 44, and the thermally conductive material 70 deforms to reduce its thickness. In other words, the width (front-to-back dimension) of the thermally conductive material 70 increases. Therefore, as... Figure 6 , Figure 7 As shown, from a top view, the thermally conductive material 70 diffuses throughout the battery support surface 50 of the first installation area 44, and as... Figure 6 As shown, the thickness of the thermally conductive material 70 is approximately the same along its entire length (the entire left-right direction). That is, the thermally conductive material 70 is in contact with almost the entire battery support surface 50 and the bottom surface of the battery stack 76, except for the left and right end plates 77.

[0074] Furthermore, the battery module mounting device in S19 holds another battery module 75 installed in the storage device, such as Figure 8 As shown, the battery module 75 is positioned directly above the battery support surface 50 of the second mounting area 45. Furthermore, the battery module mounting device moves the battery module 75 downwards, as... Figure 9 As shown, the mounting portion 79 of each lower bracket 78 is placed on the upper surface of the corresponding flange 42A. Consequently, the thermally conductive material 71 is clamped by the lower surface of the battery stack 76 and the battery support surface 50 of the second mounting region 45, causing the thermally conductive material 71 to deform, reducing its thickness and increasing its width. Therefore, as... Figure 7As shown, from a top view, the thermally conductive material 71 diffuses throughout the battery support surface 50 of the second installation area 45. Furthermore, as... Figure 9 As shown, the thermally conductive material 71 is in contact with the battery support surface 50 as a whole and almost the entire bottom surface of the battery stack 76, except for the left and right end plates 77.

[0075] Furthermore, in S19, the battery module mounting device sequentially places the battery module 75 mounted in the storage device onto the heat-conducting material coated on the upper surface of the battery support surface 50 in the third mounting region 46 and onto the heat-conducting material coated on the upper surface of the battery support surface 50 in the fourth mounting region 47.

[0076] Furthermore, in S19, the battery module mounting device holds multiple bolts (not shown in the diagram), inserts each bolt from above into the through holes (not shown in the diagram) formed on the mounting portions 79 and 82 of each battery module 75, and screws each bolt into the threaded holes (not shown in the diagram) formed on each flange 42A. Thus, as... Figure 10 As shown, each battery module 75 located in the first setting area 44, the second setting area 45, the third setting area 46, and the fourth setting area 47 is fixed to the lower housing.

[0077] The CPU, having completed processing in S19, proceeds to S20. Thereby, the lower housing 40 and junction box 59 are moved from the support platform 12 to other positions via the transport reversing device 24.

[0078] After the CPU finishes processing in S20, it enters S21, resets the column counter, and restores the column count value to "1".

[0079] The CPU that has finished processing S21 temporarily terminates the processing of this flowchart.

[0080] Furthermore, an upper housing (not shown) is then installed on the upper part of the lower housing 40, which is integrated with the four battery modules 75, thus completing the battery pack (not shown). Moreover, the battery housing 35 is formed by the lower housing 40, the junction box 59, and the upper housing.

[0081] According to the battery pack manufacturing method described above, the shape, including its height, of each battery support surface 50 of the bottom plate portion 41 of the lower housing 40 is measured by the vertical distance between the cleaning distance measuring device 14 and the battery support surface 50. Based on the measured shape of the battery support surface 50, an information code 61 containing information representing that shape is created. Furthermore, a code forming body 60 including the created information code 61 is provided in a part of the battery housing 35, namely the junction box 59. Moreover, based on the information representing the shape (height) of the battery support surface 50 obtained by reading the information code 61 through the camera 22, a liquid thermally conductive material with adhesive properties is coated onto each battery support surface 50. At this time, the amount of thermally conductive material coated on each portion (area) arranged in the left-right direction on the battery support surface 50 increases as the height of each portion decreases (the vertical distance is greater). More specifically, the lower the average height of the entire area of ​​each processing unit portion of the battery support surface 50 (the greater the average vertical distance), the more thermally conductive material is coated on the processing unit portion.

[0082] Typically, the lower housing 40 cannot be molded according to the designed shape. For example, during the molding of the lower housing 40, when the resin material cures, deformation sometimes occurs in a part of the lower housing 40. For example, since the mechanical strength of the part where the base plate portion 41 is formed is lower than that of the part where the rib 43 is formed, the battery support surface 50 of the second setting region 45 is molded as a curved surface as described above.

[0083] Figure 12 and Figure 13 This is a cross-sectional view taken along the second installation area 45 of the lower housing 40 of the comparative example. (See figure) Figure 12 As shown, the battery support surface 50 of the second setting area 45 is a curved surface. In this case, assuming as follows... Figure 12 The case shown is where the upper surface of the battery support surface 50 in the second setting area 45 is coated with a thermally conductive material 85 in a constant thickness. Figure 13 Indicates in Figure 12 The battery module 75 is placed on the thermally conductive material 85 and fixed to the lower housing 40. In this case, as... Figure 13 As shown, at least a portion of the central part of the bottom surface of the battery stack 76 is away from the thermally conductive material 85. Therefore, as Figure 14 As shown, the thermally conductive material 85 does not diffuse as a whole into the battery support surface 50 of the second mounting region 45. Therefore, in this case, the contact area between the thermally conductive material 85 and the bottom surface of the battery stack 76, and the contact area between the thermally conductive material 85 and the battery support surface 50, become smaller. That is, in this case, the heat from the battery module 75 is not efficiently transferred to the lower housing 40 through the thermally conductive material 85.

[0084] In contrast, in this embodiment, the greater the average vertical distance of the entire area of ​​each processing unit portion of the battery support surface 50, the more thermally conductive material is coated on the processing unit portion. In other words, the smaller the average height of the entire area of ​​each processing unit portion, the more thermally conductive material is coated on the processing unit portion. Therefore, even if the battery support surface 50 of the second setting area 45 is a curved surface, as described above, the thermally conductive material 71 is in contact with almost the entire battery support surface 50 and the bottom surface of the battery stack 76, except for the left and right end plates 77. Therefore, in the battery pack manufactured by the manufacturing method of this embodiment, the heat of the battery module 75 is efficiently transferred to the lower housing 40 through the thermally conductive materials 70 and 71, thus preventing the battery module 75 from becoming excessively hot.

[0085] Furthermore, in the battery pack manufacturing method of this embodiment, the discharge pressure of the thermally conductive material is changed based on the average vertical distance between each processing unit located directly below the coating apparatus 18. That is, the discharge pressure of the coating apparatus 18 remains constant while it moves directly above each processing unit. Therefore, compared to the case where the discharge pressure is precisely changed based on the vertical distance represented by the correction shape line CDL, the control of the CPU-based discharge control mechanism 21 is easier.

[0086] Furthermore, in the battery pack manufacturing method of this embodiment, the discharge pressure (discharge amount) of the thermally conductive material of the coating apparatus 18 is determined by considering the inclination of the lower housing 40 relative to the horizontal line HL. Therefore, even when the lower housing 40 is inclined relative to the horizontal line HL, the thermally conductive material is made to contact the battery module 75 and the battery support surface 50 over a large area.

[0087] The above describes the manufacturing method of the battery pack according to the embodiments, but these can be appropriately modified without departing from the spirit of the present invention.

[0088] For example, the correction calculation unit may not average the vertical distance represented by the acquired correction shape line CDL across the eight processing unit locations. That is, the amount of thermally conductive material coated on multiple locations arranged in the left-right direction on the battery support surface 50 may be increased as the height of the location decreases, in a manner different from the embodiment. In this case, the CPU precisely adjusts the discharge pressure of the thermally conductive material in the coating apparatus 18 according to the vertical distance represented by the correction shape line CDL. Therefore, compared to the case where the thermally conductive material is averaged across the vertical distance of the processing unit locations, it is easier for the thermally conductive material to contact almost the entire battery support surface 50 and almost the entire bottom surface of the battery stack 76, except for the left and right end plates 77.

[0089] Alternatively, the discharge pressure of the thermally conductive material in the coating apparatus 18 can be set to be constant regardless of the vertical distance between the cleaning distance measuring device 14 (distance measuring unit) and the battery support surface 50, and the moving speed of the coating apparatus 18 can be changed according to the change in this vertical distance. That is, the moving speed of the coating apparatus 18 located directly above the portion of the battery support surface 50 (processing unit portion) with a large vertical distance can be reduced, while the moving speed of the coating apparatus 18 located directly above the portion of the battery support surface 50 (processing unit portion) with a small vertical distance can be increased.

[0090] The code forming body 60 can also be located at a different part of the battery housing 35 than at the junction box 59. Furthermore, the battery housing 35 can also have a component that is different from the lower housing 40, the junction box 59, and the upper housing, on which the code forming body 60 is provided.

[0091] The code creation device 26 can also engrave or print information codes on a portion of the battery casing 35.

[0092] The stacking direction of each battery cell in the battery pack (the extension direction of the battery module) and the extension direction of the battery support surface 50 can be different from the left and right directions.

[0093] Symbol Explanation

[0094] 14-Cleaning distance measuring device (distance sensor), 30-Control device, 35-Battery housing, 50-Battery support surface, 61-Information code, 70, 71, 85-Heat-conducting material, 75-Battery module.

Claims

1. A method for manufacturing a battery pack, characterized in that, Includes the following steps: The measurement step involves measuring the shape of the battery support surface, including its height. The battery support surface is a portion of the bottom surface of a battery housing that houses a battery module having multiple battery cells stacked in a predetermined direction and extends along the predetermined direction. The information code creation step involves creating an information code containing information representing the shape, based on the measured shape of the battery support surface. The information code assignment step involves setting the created information code onto the battery casing; The reading step involves reading in the information code. In the coating step, based on the information representing the shape of the battery support surface as indicated by the information code obtained by reading, a liquid thermally conductive material with adhesive function is coated on the battery support surface, such that the amount of thermally conductive material coated on multiple locations arranged along the predetermined direction on the battery support surface increases as the height of the location decreases. and In the battery module placement step, the bottom surface of the battery module is placed on the upper surface of the thermally conductive material.

2. The method for manufacturing a battery pack according to claim 1, characterized in that, The battery support surface has multiple processing unit portions arranged along the specified direction. The method for manufacturing the battery pack includes a correction step, which involves calculating the average height of the entire area of ​​the processing unit. The coating step is a step in which the lower the average value, the more thermally conductive material is coated on the processing unit area.

3. The method for manufacturing a battery pack according to claim 1 or 2, characterized in that, The measurement step includes measuring the height of both ends of the battery support surface in the specified direction. In this measurement step, a ranging sensor, moving from one end of the battery support surface to the other in the specified direction, measures the shape directly above the battery support surface. The method for manufacturing the battery pack further includes a correction step, wherein, given that a straight line passing through the two ends, determined based on the measured heights of the two ends, is inclined relative to a horizontal line, the height of each of the plurality of processing unit portions is corrected to the height at which the battery casing is rotated to align the straight line with the horizontal line. The information code creation step is a step of creating the information code containing information representing the shape, the shape including the modified height.

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