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EP-4322320-B1 - BATTERY PACK

EP4322320B1EP 4322320 B1EP4322320 B1EP 4322320B1EP-4322320-B1

Inventors

  • UNNO, AKIRA
  • SUGAWARA, TATSUO
  • HOSHI, HIROSHI

Dates

Publication Date
20260513
Application Date
20210928

Claims (5)

  1. A battery pack comprising a plurality of batteries (101) stacked and arranged in the longitudinal direction of the battery pack, a bus bar (120) connected to electrode terminals (104, 105) of the plurality of batteries, a terminal (140) connected to the bus bar, and an electric wire (130) connected to the terminal, wherein the terminal has a first base portion (141) that is located on one end side in a lateral direction of the terminal and is bonded to the bus bar in a vertical direction by ultrasonic welding, a second base portion (142) that is located on the other end side in the lateral direction and is connected to the electric wire, and a protrusion portion (143) that is located between the first base portion and the second base portion and protrudes in the vertical direction; wherein the protrusion portion protrudes in the vertical direction to the side of the plurality of batteries, and characterized in that the electric wire is connected to the second base portion on the side to which the protrusion portion protrudes in the terminal.
  2. The battery pack according to claim 1, wherein the second base portion (142) has a first connection portion (146a) which is located on the side of the first base portion (141) and is connected to an uncovered portion (130a) of the electric wire, and a second connection portion (146b) which is located on the side opposite to the first base portion and to which a portion (130b) covered with a covering member of the electric wire (130) is fixed.
  3. The battery pack according to claim 1, wherein in the protrusion portion (143), a first height of an apex of the protrusion portion with respect to a portion continuous with the first base portion (141) is lower than a second height of the apex with respect to a portion continuous with the second base portion (142), in cross-sectional view in the vertical direction.
  4. The battery pack according to claim 1, wherein in the protrusion portion (143), a first height of an apex of the protrusion portion with respect to a portion continuous with the first base portion (141) is higher than a second height of the apex with respect to a portion continuous with the second base portion (142), in cross-sectional view in the vertical direction.
  5. The battery pack according to claim 1, wherein a cross-sectional shape of the protrusion portion (143, 343, 443) in the vertical direction is a curved shape, a bent shape, or a rectangular shape.

Description

Technical Field The present invention relates to a battery pack. Background Art Conventionally, there is a secondary battery module including a voltage detection terminal in which a crank shape is formed between a "temporarily fixing portion" laser-welded to a bus bar and an "electrical connection portion" connected to an electric wire (see, for example, Patent Literature 1). Citation List Patent Literature Patent Literature 1: Japanese Patent No. 6335864 An electro-chemical cell contacting system having the features in the pre-characterizing portion of Claim 1 is disclosed in JP 2020 087650 A. A further battery back related to the one of the present invention is disclosed in US 2017/133656 A1. Summary of Invention Technical Problem However, in the above-described conventional technology, when the voltage detection terminal and the bus bar are ultrasonically bonded, disconnection of the electric wire occurs at the connection portion between the voltage detection terminal and the electric wire. That is, in the case of the shape of the voltage detection terminal as in the above-described conventional technology, there is a problem that the vibration load of ultrasonic welding directly propagates to the connection portion, and the disconnection of the electric wire occurs due to the vibration load. Here, although the vibration load transmitted to the connection portion can be suppressed by pressing the connection portion, the structure of the secondary battery module merely presses the connection portion from a direction perpendicular to a vibration direction of the ultrasonic welding, so that an effect of suppressing the vibration load is small. The present invention has been made in view of the above, and an object thereof is to prevent disconnection and damage of an electric wire connected to a voltage detection terminal when the voltage detection terminal is ultrasonically welded. Solution to Problem In order to solve the above-described problems of the conventional technology, the present invention provides the battery pack defined in Claim 1. Further advantageous features are set out in the dependent claims. Advantageous Effects of Invention According to the present invention, when a voltage detection terminal is ultrasonically welded, disconnection and damage of an electric wire connected to the voltage detection terminal can be prevented. Brief Description of Drawings Fig. 1 is an external perspective view of a secondary battery module.Fig. 2 is an exploded perspective view of the secondary battery module.Fig. 3 is a perspective view of a secondary battery.Fig. 4 is an exploded perspective view of configurations of a harness case, a voltage detection line, and a bus bar as viewed from the Z-axis negative direction side.Fig. 5 is a perspective view of a voltage detection terminal according to a first embodiment.Fig. 6 is a schematic view illustrating bonding results by ultrasonic welding and laser welding.Fig. 7 is a perspective view of a voltage detection terminal according to a second embodiment as an example useful for understanding the invention rather than an embodiment of the invention.Fig. 8 is a perspective view of a voltage detection terminal according to a third embodiment.Fig. 9 is a perspective view of a voltage detection terminal according to a fourth embodiment.Fig. 10 is a perspective view of a voltage detection terminal according to a fifth embodiment.Fig. 11 is a perspective view of a voltage detection terminal according to a sixth embodiment.Fig. 12 is a perspective view of a voltage detection terminal according to a seventh embodiment as an example useful for understanding the invention rather than an embodiment of the invention. Description of Embodiments Hereinafter, embodiments of the present invention and embodiments as examples useful for its understanding will be described in detail with reference to the drawings. The following embodiments can be applied to a battery system constituting a power supply of a hybrid vehicle, a plug-in hybrid vehicle, an electric vehicle, a hybrid truck, a railway vehicle, or the like. In addition, the following embodiments can be applied to a battery system including a chargeable and dischargeable secondary battery such as a lithium ion battery, a lead battery, a nickel hydrogen battery, a polyvalent cation battery, an electric double layer capacitor, or a hybrid capacitor. In the following embodiments, a battery pack in which a plurality of secondary battery cells are connected in series is exemplified as an application target of the present invention. However, the present invention can also be applied to a battery pack in which a plurality of secondary battery cells connected in parallel are connected in series, or a battery pack in which a plurality of secondary battery cells connected in series are connected in parallel. In the following description, the same reference numerals are given to the same configurations, and redundant description wil