Forming method

Abstract

To provide a molding method that does not require specialized equipment and can achieve high cycle and high quality at low cost and in a small space. [Solution] The molding method involves transporting the energy storage module 24 to molds 21, 22, and 23, which have holes 25-1 to 25-n through which air passes in the internal resin flow section. Warm air is then blown through the holes to preheat the area where the liquid injection port will be formed on the energy storage module 24. After preheating, resin is injected into the molds 21, 22, and 23 to perform injection molding.

Description

Technical Field

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[0001] The present invention relates to a molding method, for example, a molding method for a liquid injection port using a novel resin mold for a large-sized power storage module such as a lithium-ion battery.

Background Art

[0002] Patent Document 1 describes a technique for suppressing variations in residual stress in a module resin part by applying pressure while heating a power storage module, and preventing deformation such as warping of the module.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, since the heating range covers the entire circumference of the power storage module, there is a problem that large energy and equipment size are required because pressurization is premised. Also, in Patent Document 1, since the heating range covers the entire circumference of the power storage module, there is a problem that temperature unevenness is large and quality assurance is difficult. Furthermore, in Patent Document 1, since the equipment size is large and installation is premised on independent processes, there is a problem that shortening the cycle time is difficult. And, in Patent Document 1, since the heating range covers the entire circumference of the power storage module, the size is limited to one pattern. That is, there is also a problem that it cannot correspond to electrode sizes of multiple patterns.

Means for Solving the Problems

[0005] A molding method according to an embodiment preheats a location where a liquid injection port is to be formed on a power storage module, and after preheating, injects resin into a mold to perform injection molding.

Effects of the Invention

[0006] According to the molding method disclosed herein, high cycle and high quality can be achieved at low cost and in a small space, without the need for specialized equipment. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing an example of a molding method according to Embodiment 1. [Figure 2] This is a schematic diagram showing the details of the preheating process in the molding method according to Embodiment 1. [Figure 3] This is a perspective view showing an example of a power storage module and liquid injection port in the molding method according to Embodiment 1. [Modes for carrying out the invention]

[0008] Embodiment 1 Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing an example of a molding method according to Embodiment 1.

[0009] As shown in Figure 1, the mold to be molded is first replaced during the pre-injection stage changeover. Next, the molding area is preheated, and then injection molding is performed. Then, during the post-injection stage changeover, the mold and inserts are disassembled, tab cutting is performed, the inserts are cleaned, and inspection is carried out.

[0010] In this series of steps, during the preheating stage, hot air is blown onto the molding area. Figure 2 is a schematic diagram showing the details of the preheating in the molding method according to Embodiment 1.

[0011] As shown in Figure 2, the part 24 to be molded is inserted into the space formed by the upper mold 21, the lower mold 22, and the horizontal mold 23. Then, air passages 25-1 to 25-n (where n is a natural number) are formed in the mold at positions corresponding to the molding area of ​​the part 24, and hot air is flowed through them. This hot air heats the molding area of ​​the part 24. After that, resin is injected and injection molding is performed. This preheats the molding area, ensuring good adhesion between the injection port 32 and the part 24. The hot air is supplied by a hot air generator (not shown).

[0012] Figure 3 shows an example of forming the liquid injection port of the energy storage module using this preheating method. Figure 3 is a perspective view showing an example of an energy storage module and liquid injection port in the molding method according to Embodiment 1.

[0013] As shown in Figure 3, the energy storage module 31 is, for example, a large-sized (e.g., 1500 mm x 1200 mm) Li-ion battery module. An electrolyte injection port 32 is provided on the side of this energy storage module 31. The energy storage module 31 in Figure 3 corresponds to the component 24 in Figure 2, and the electrolyte injection port 32 is formed by injection molding of resin.

[0014] Next, I will explain the effect of preheating.

[0015] Table 1 shows the compatibility (merging) of the resin and workpiece during injection molding under different conditions. [Table 1] In Table 1, "Pre: None" means that injection molding is performed without preheating. "Pre: Yes" means that injection molding is performed after preheating. The VP switching position is the position where the setting switches from V (injection speed) to P (holding pressure).

[0016] From the results in Table 1, by performing preheating before injection molding, it is possible to ensure robustness against variations in the unevenness on the side surface of the laminate. It is considered that the influence of the mold temperature is small. And by preheating the mold and the workpiece to about 60 °C during injection molding, compatibility can be ensured. Note that the preheating temperature must not exceed the softening point of the adhesive for electrode foil lamination. For example, in Table 1 above, the heat source is up to 75 °C.

[0017] According to the molding method of Embodiment 1 in this way, since a hot air circuit is incorporated in the mold, dedicated equipment (such as a furnace and a blower) is not required, and high cycle and high quality can be achieved at low cost and in a space-saving manner.

Explanation of Reference Signs

[0018] 21 Upper mold 22 Lower mold 23 Side mold 24 Part 25-1|25-n Hole passage 31 Power storage module 32 Liquid injection port

Claims

[Claim 1] The energy storage module is transported to a mold in which holes are formed for air to pass through the internal resin fluid section. By flowing warm air through the aforementioned tunnel, the area where the liquid injection port is to be formed in the energy storage module is preheated. A molding method in which resin is injected into a mold after preheating and then injection molding is performed.

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