Punch, die and stretching process for stretching battery jar body

Abstract

The invention discloses a punch, a die and a stretching process for stretching a battery jar body. The punch characterized in that a step punch is specially designed to serve as a male die, at least one thinning ring serves as a female die, and the wall thickness of the jar body is changed. The variable wall thickness stretching process belongs to thinning stretching, when a sheet or a plate is subjected to at least one-time forming stretching to obtain a cup-shaped stretching piece, the cup-shaped stretching piece is subjected to thinning stretching, particularly, variable wall thickness stretching in which the step punch is matched with at least one thinning ring is adopted to finally obtain a middle-section thin wall, and one or two battery jar bodies with variable wall thickness at theaxial end parts are provided. According to the variable-wall-thickness battery jar body, on one hand, the material consumption of the middle section of the jar body can be reduced, and on the other hand, the seaming strength of one or two ends of the jar body can be ensured; and therefore, the contradictory problem between the amount of used materials and the sealing strength caused by the thickand thin wall of the battery jar body is well solved.

Description

technical field [0001] The invention relates to the field of can body processing, in particular to a punch for stretching a battery can body, a mold and a stretching process thereof. Background technique [0002] New energy vehicles use battery packs as the power source of the whole vehicle. There are multiple battery cells in the battery pack. The battery cells are the smallest units that constitute the new energy battery system. They are composed of positive electrodes, negative electrodes and electrolytes. The outer shell of the battery pack is a battery can, and a plurality of assembled battery cells are gathered and arranged in the battery pack in a state of parallel axes. [0003] The battery can is composed of a can body and a can cover. In the prior art, the tank body is usually processed by a cold pressing process, and the formed tank body and the tank cover are processed into one body by welding. However, the reliability and stability of the end of the welded bat...

AI Technical Summary

Problems solved by technology

However, there is currently no stretching process for seam-sealing battery cans, and the stretching process for other types of cans usually only stretches out cans with the same wall thickness

Therefore, when designing a seam-sealed battery can, it is necessary to pay attention to the wall thickness of the battery can: if the wall thickness of the can is too thick, it will not only increase the cost of materials, but also increase the weight of the battery pack, resulting in an increase in the energy density of the overall battery pack. If the wall thickness of the tank is too thin, there will be problems such as easy tearing of the end of the tank during the seaming process or instability during use after seaming

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