JP2005228652A - Manufacturing method of battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a battery pack capable of shortening a manufacturing period while properly covering an outer peripheral surface of a unit battery and an electric component by a resin mold. <P>SOLUTION: The resin mold 2 is formed on an intermediate assembly 13 formed by temporarily assembling the electric component on the unit battery 1. The resin mold 2 is formed through processes comprising: a mounting process positioning and mounting the temporarily asssembled intermediate assembly 13 on a first lower mold 15; a primary molding preparation process jointing an upper mold 14 to the lower mold 15 after mounting the intermediate assembly 13 thereon; a primary molding process forming a primary molded part 2a of the resin mold 2; a secondary molding preparation process jointing the upper mold 14 including the intermediate assembly 13 after the first molding to a second lower mold 16; a secondary molding process forming a secondary molded part 2a of the resin mold 2; and a take-out process taking out the intermediate assembly 13 after the secondary molding from the second lower mold 16. A mounting process of the next coming intermediate assembly 13 is proceeded during the preceding secondary molding process of the intermediate assembly 13, and a take-out process of the preceding intermediate assembly 13 is proceeded during the next coming primary molding process of the intermediate assembly 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a battery pack in which an outer peripheral surface of a unit cell and an electrical component is covered with a resin mold in an intermediate assembly in which electrical components are temporarily assembled on the outer peripheral surface of the unit cell.

  In Patent Documents 1 and 2, an intermediate assembly in which electrical components such as a circuit board are temporarily assembled on the outer peripheral surface of a unit cell is set in a mold, molten resin is injected into a cavity of the mold, and a resin mold is used. Manufacturing a battery pack in which a battery and an electrical component are integrated is disclosed.

Japanese Patent Laid-Open No. 2002-134077 (paragraph numbers 0021-0023, FIG. 3) JP 2003-86159 A (paragraph numbers 0059 and 0065-0066, FIG. 16)

  When setting the intermediate assembly in the cavity of the mold, a gap is required between the inner wall surface of the cavity and the intermediate assembly for the molten resin to flow and mold the resin mold. For this reason, interchangeability occurs in the intermediate assembly in a state where it is set in the cavity, and the intermediate assembly moves in the cavity when the molten resin is injected. As a result, there is a portion where the resin mold becomes thin, and there is a risk that insulation and protection of the electrical components in the resin mold will be insufficient.

  As a countermeasure, it is conceivable to mold the resin mold in two steps. That is, after positioning the front and rear left and right outer peripheral surfaces of the lower side of the intermediate assembly against the inner wall surface of the lower mold cavity, the peripheral surface of the intermediate assembly exposed in the upper mold cavity is filled with molten resin, A primary molding portion of the resin mold is formed. Thereafter, the remaining resin mold that could not be formed by contact with the inner wall surface of the cavity of the lower mold during the primary molding is subjected to secondary molding.

  In this case, since the resin mold is molded in two steps, it takes time to mold the resin mold, and there is a problem that the manufacturing time of the battery pack becomes long and the manufacturing efficiency is deteriorated.

  An object of the present invention is to provide a battery pack manufacturing method capable of reducing the time required for manufacturing the battery pack while properly covering the outer peripheral surfaces of the unit cell and the electrical component with a resin mold.

  In the present invention, as shown in FIG. 1, a resin mold 2 that covers the outer peripheral surface of the unit cell 1 and the electrical component with respect to the intermediate assembly 13 in which the electrical component is temporarily assembled on the outer peripheral surface of the rectangular box-shaped unit cell 1. And the mold for molding the resin mold 2 is an upper mold 14, a first lower mold 15 and a second lower mold 16 as shown in FIGS. And a lower mold integrated with the left and right. As shown in FIG. 9, the resin mold 2 includes a mounting process for mounting and positioning the intermediate assembly 13 after temporary assembly in the cavity 19 of the first lower mold 15, and a first lower mold after mounting the intermediate assembly 13. Primary molding preparatory step for joining the upper die 14 to 15 and a primary molding portion 2a of the resin mold 2 by pouring molten resin into the cavities 18 and 19 of the upper die 14 and the first lower die 15 A secondary molding preparation step in which an upper die 14 including the intermediate assembly 13 after the primary molding is separated from the first lower die 15 and joined to the second lower die 16; The molten resin is poured into the cavity 20 to perform a secondary molding step for forming the secondary molding portion 2b of the resin mold 2 and a removal step for removing the intermediate assembly 13 after the secondary molding from the second lower mold 16. Form with. At that time, during the secondary molding process for the preceding intermediate assembly 13, the mounting process for the next intermediate assembly 13 is performed, and during the primary molding process for the next intermediate assembly 13, A take-out process is performed on the preceding intermediate assembly 13.

  Specifically, the upper mold 14 moves only in the vertical direction, and the lower mold slides only in the horizontal direction. In the primary molding preparation step, the upper mold 14 is raised while the intermediate assembly 13 after the secondary molding is left in the second lower mold 16, and the lower mold is slid and moved below the upper mold 14. After the mold 15 is positioned, the upper mold 14 is lowered and joined to the first lower mold 15. In the secondary molding preparation step, the upper mold 14 including the intermediate assembly 13 after the primary molding is raised, the lower mold is slid and the second lower mold 16 is positioned below the upper mold 14, and then the upper mold 14 descends and joins to the second lower mold 16.

  A runner 22 is formed in each of the lower surface of the upper die 14 and the upper surface of the second lower die 16 so that the upper die 14 and the second lower die 16 are joined to each other. 2 The runner 22 of the lower mold 16 overlaps the top and bottom. In the primary molding step, the molten resin flows into the cavities 18 and 19 of the upper mold 14 and the first lower mold 15 through the runner 22 of the upper mold 14. In the secondary molding step, the molten resin can flow into the cavity 20 of the second lower mold 16 via the runner 22 of the second lower mold 16.

  According to the present invention, the intermediate assembly 13 is positioned by the first lower mold 15 to perform the primary molding of the resin mold 2, and the upper mold 14 is left in the second mold while the intermediate assembly 13 after the primary molding remains. Since the secondary molding is performed by joining to the lower mold 16, the intermediate assembly 13 does not move in the cavity during the primary molding or the secondary molding, and the outer peripheral surface of the unit cell 1 and the electrical component is made of resin. The mold 2 can be properly covered. Since the upper die 14, the first lower die 15, and the second lower die 16 are sufficient, the number of dies required for the primary and secondary molding can be reduced.

  In addition, while the secondary molding process is being performed on the preceding intermediate assembly 13, the mounting process on the next intermediate assembly 13 is performed, and during the primary molding process on the next intermediate assembly 13. Since the removal step is performed on the preceding intermediate assembly 13, the molding time of the resin mold 2 per battery pack P can be shortened by the time of the mounting step and the removal step. Therefore, even if the resin mold 2 is molded in two steps, the production of the battery pack P does not take a long time, and a reduction in the production efficiency of the battery pack P can be reduced.

  If the upper die 14 moves only in the vertical direction and the lower die slides only in the left-right direction, the driving mechanism of the upper die 14 and the lower die can be simplified. In addition, in the primary molding preparation process, the second lower mold 16 including the intermediate assembly 13 after the secondary molding slides away from the lower side of the upper mold 14, and in the secondary molding preparation process, the first lower mold 15 When the intermediate slide 13 is moved away from the lower side of the upper die 14 and removed, the intermediate assembly 13 after the secondary molding is removed from the second lower die 16 or the next intermediate assembly 13 is attached to the first lower die 15. In addition, the upper mold 14 does not get in the way, and the workability of taking out and mounting the intermediate assembly 13 is improved.

  When the runner 22 of the upper mold 14 and the runner 22 of the second lower mold 16 are vertically overlapped, the cavities 18 and 19 of the upper mold 14, the first lower mold 15, and the second lower mold 16 are formed by one nozzle 23. -Molten resin can be poured into 20, and the mechanism for shaping | molding the resin mold 2 can be simplified.

  1 to 3 show a battery pack P to which the present invention is directed. A flat rectangular box-shaped unit cell 1, electrical components disposed on front, rear, left and right outer peripheral surfaces of the unit cell 1, and a unit cell 1 includes a resin mold 2 for integrating electrical components.

  The unit cell 1 is formed into a rectangular flat rectangular box whose upper and lower surfaces are substantially flat and whose vertical and vertical thickness dimensions are smaller than the front and rear width dimensions and the left and right width dimensions. The resin mold 2 covers the electrical component and the front, rear, left and right outer peripheral surfaces excluding the upper and lower surfaces of the unit cell 1, and is made of polyamide resin, styrene elastomer resin, ethylene / vinyl acetate (EVA), polyurethane (PUR). Molded with a hot melt resin.

The unit cell 1 is composed of a secondary battery capable of charging and discharging, for example, a lithium ion battery, in which an electrode body and an electrolytic solution are enclosed in an outer can 4. The sealing plate closes the front surface of the outer can 4 as shown in FIG. 2. A negative electrode terminal 6 is provided at the center of 5. The outer can 4 is a deep-drawn product of an aluminum plate, and the sealing plate 5 is formed of an aluminum alloy plate. The electrode body is formed by spirally winding a positive electrode sheet using LiCoO ₂ as an active material and a negative electrode sheet using graphite as an active material with a synthetic resin separator sandwiched between them. Has been.

  In FIG. 2, the electrical components are a circuit unit 7, a short lead wire 8 and a protective cover 9, which are respectively disposed on the front side of the unit cell 1, a thermal fuse 10 disposed on the rear side of the unit cell 1, and the unit cell 1. And a long lead wire 11 disposed on the lateral side of the wire. The circuit unit 7 is provided with a protection circuit for preventing overdischarge or overcharge of the unit cell 1 and has an external output terminal 12 facing the outside. The thermal fuse 10 interrupts the current of the unit cell 1 when the temperature of the unit cell 1 exceeds a set value.

  The short lead wire 8 is welded to the negative electrode terminal 6 and the circuit unit 7 respectively, and the long lead wire 11 is welded to the circuit unit 7 and the thermal fuse 10 respectively. These electrical components are temporarily assembled on the front, rear, left, and right outer peripheral surfaces of the unit cell 1 to obtain an intermediate assembly 13 shown in FIG.

  As shown in FIGS. 4 and 5, the mold for molding the resin mold 2 includes an upper mold 14 that is operated to move only in the vertical direction and a lower mold that is operated to slide only in the horizontal direction. The lower mold is formed by integrating the first lower mold 15 and the second lower mold 16 side by side. The resin mold 2 is molded in two steps by the mold. The lower half of the intermediate assembly 13 after temporary assembly shown in FIG. 3 is mounted in the cavity 19 of the first lower mold 15, and the positioning of the intermediate assembly 13 in the front-rear and left-right directions is set on the inner wall of the cavity 19. .

  As shown in FIGS. 5 and 6, the upper half of the intermediate assembly 13 is fitted into the cavity 18 of the upper mold 14. The primary mold part 2a of the resin mold 2 is formed by joining the upper mold 14 to the first lower mold 15 and injecting molten resin therebetween. Incidentally, the intermediate assembly 13 is sandwiched and held between the first and second lower molds 14 and 15 and positioned in the vertical direction. As shown in FIGS. 7 and 8, the lower half of the intermediate assembly 13 after the primary molding is fitted into the cavity 20 of the second lower mold 16, and the intermediate assembly 13 after the primary molding is inserted. The secondary mold portion 2b of the resin mold 2 is formed by joining the upper mold 14 including the second lower mold 16 and injecting a molten resin therebetween.

  6 and 8, a runner 22 having a trapezoidal cross section is formed in each of the lower surface of the upper die 14 and the upper surface of the second lower die 16, and the upper die 14 and the second lower die 16 are joined to each other. In this state, the runner 22 of the upper mold 14 and the runner 22 of the second lower mold 16 overlap each other. During the primary molding, the molten resin flows from the nozzle 23 into the cavities 18 and 19 of the upper mold 14 and the first lower mold 15 through the runner 22 of the upper mold 14. At the time of secondary molding, the runner 22 of the upper mold 14 is clogged with the resin at the time of primary molding, so that the molten resin flows from the nozzle 23 through the runner 22 of the second lower mold 16 to the second lower mold 16. It flows into the cavity 20.

  The injection pressure of the molten resin is preferably high from the viewpoint of the injection speed, but if it is excessively high, the unit cell 1 is damaged. The temperature of the molten resin was set to about 200 ° C. Air passages 24 are provided in the upper wall of the upper mold 14 and the lower walls of the first and second lower molds 15 and 16, respectively, and air is sent to the cavities 18, 19, and 20 through the air passage 24, The molded intermediate assembly 13 can be easily removed from the mold.

  The process on the first lower mold 15 side and the process on the second lower mold 16 side are performed in parallel. That is, as shown in FIG. 9A, the next intermediate assembly 13 before the molding of the resin mold 2 is mounted in the cavity 19 of the first lower mold 15, and the intermediate assembly 13 is formed on the inner wall of the cavity 19. Position in the front / rear / right / left direction (mounting process). At this time, the upper die 14 including the preceding intermediate assembly 13 after the primary molding is joined to the second lower die 16, and the molten resin passes through the runner 22 of the second lower die 16 from the nozzle 23. It is poured into the cavity 20 of the second lower mold 16 and filled around the peripheral surface of the preceding intermediate assembly 13 and the electrical components. Next, the filled molten resin is held and cooled to be solidified, whereby a secondary molding portion 2b of the resin mold 2 is formed on the preceding intermediate assembly 13 (secondary molding step).

  Subsequently, as shown in FIG. 9 (b), the upper die 14 is separated from the second lower die 16 with the preceding intermediate assembly 13 after the secondary molding left in the second lower die 16. Further, the first lower mold 15 including the next intermediate assembly 13 is positioned below the upper mold 14 by sliding the lower mold to the right. Thereafter, the upper die 14 is lowered and joined to the first lower die 15 (primary molding preparation step).

  Next, as shown in FIG. 9 (c), molten resin is poured from the nozzle 23 into the cavities 18 and 19 of the upper die 14 and the first lower die 15 through the runner 22 of the upper die 14, and the next intermediate assembly 13. Fill the peripheral surface of the product and around the electrical components. The filled molten resin is solidified by holding and cooling, thereby forming the primary molding portion 2a of the resin mold 2 (primary molding step). During this primary molding, in the second lower mold 16, the preceding intermediate assembly 13 (battery pack P) for which the formation of the resin mold 2 has been completed is removed (removal step).

  Subsequently, as shown in FIG. 9D, the upper die 14 including the next intermediate assembly 13 (FIG. 10) after the primary molding is separated upward, and the lower die is slid leftward to move the upper die. The second lower mold 16 is positioned below 14 and the upper mold 14 is lowered and joined to the second lower mold 16 (secondary molding preparation step).

  Thereafter, the above-described secondary molding step shown in FIG. 9A is performed on the next intermediate assembly 13, and the next intermediate assembly 13 is further moved to the first lower mold during the secondary molding step. 15 is attached. Thereafter, these steps are repeated.

  In this way, during the secondary molding process for the preceding intermediate assembly 13, the mounting process for the next intermediate assembly 13 is performed, and during the primary molding process for the next intermediate assembly 13. Since the removal process is performed on the preceding intermediate assembly 13, the molding time of the resin mold 2 per battery pack P can be shortened by the time of the mounting process and the removal process.

  Specifically, 10 seconds for the mounting process, 1.5 seconds for the primary molding preparation process, 20 seconds for the primary molding process, 1.5 seconds for the secondary molding preparation process, and 20 seconds for the secondary molding process. The process takes 5 seconds and takes 58 seconds as a whole. However, the process can be shortened to 43 seconds as much as the time required for the mounting process and the removal process can be reduced.

Battery pack perspective view Exploded perspective view of intermediate assembly Perspective view of intermediate assembly Lower plan cross section 4 is a cross-sectional view taken along the line AA in FIG. 4 is a cross-sectional view taken along the line B-B in FIG. Longitudinal side view corresponding to FIG. 5 showing the joining state of the upper die and the second lower die Longitudinal side view corresponding to FIG. 6 showing the joining state of the upper die and the second lower die Longitudinal side view for explaining the process of forming the resin mold on the intermediate assembly Perspective view of intermediate assembly with primary molded part

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unit cell 2 Resin mold 2a Primary molding part 2b of resin mold Secondary molding part 13 of resin mold 13 Intermediate assembly 14 Upper die 15 First lower die 16 Second lower die 18, 19, 20 Cavity 22 Runner

Claims (3)

A method of manufacturing a battery pack in which a resin mold that covers an outer peripheral surface of the unit cell and the electrical component is formed with respect to an intermediate assembly in which electrical components are temporarily assembled on the outer peripheral surface of a rectangular box-shaped unit cell. ,
The mold for molding the resin mold has an upper mold and a lower mold in which the first lower mold and the second lower mold are arranged side by side on the left and right,
A mounting step of mounting and positioning the intermediate assembly after the temporary assembly in the cavity of the first lower mold;
A primary molding preparation step of joining the upper die to the first lower die after mounting the intermediate assembly;
A primary molding step of forming a primary molding portion of the resin mold by pouring molten resin into the cavities of the upper mold and the first lower mold;
A secondary molding preparation step of separating the upper mold including the intermediate assembly after the primary molding from the first lower mold and joining to the second lower mold;
A secondary molding step of pouring molten resin into the cavity of the second lower mold to form a secondary molding portion of the resin mold;
The resin mold is formed through a removal step of removing the intermediate assembly after the secondary molding from the second lower mold,
While performing the secondary forming step on the preceding intermediate assembly, the mounting step on the next intermediate assembly is performed,
The battery pack manufacturing method, wherein the take-out step is performed on the preceding intermediate assembly during the primary forming step on the next intermediate assembly. The upper mold moves only in the vertical direction, and the lower mold slides only in the horizontal direction,
In the primary molding preparation step, the upper mold is raised while the intermediate assembly after the secondary molding is left in the second lower mold, and the lower mold is slid to move below the upper mold. After the first lower mold is positioned, the upper mold is lowered and joined to the first lower mold,
In the secondary molding preparation step, after the upper mold including the intermediate assembly after the primary molding is raised, the lower mold is slid and the second lower mold is positioned below the upper mold. The method of manufacturing a battery pack according to claim 1, wherein the upper mold is lowered and joined to the second lower mold. A runner is formed in each of the lower surface of the upper mold and the upper surface of the second lower mold so that the upper mold and the second lower mold are joined to each other. The runner of the second lower mold overlaps with the top and bottom,
In the primary molding step, molten resin flows into the cavities of the upper mold and the first lower mold through the runner of the upper mold,
The method for manufacturing a battery pack according to claim 2, wherein in the secondary molding step, molten resin flows into the cavity of the second lower mold through the runner of the second lower mold.

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