Makita Corporation

Youichi Kato

Takahide Kawakami

Kazuyuki Sakakibara

Norio Isogai

Masatoshi Sugiura

Hisakazu Okabayashi

Katsumi Tozawa

Masayoshi Kondo

Norio Isoqai

A battery pack () has a double casing structure, including an inner case () disposed inside an outer case (). The inner case () includes a radiator plate () that is in contact with the side walls of battery cells () disposed within the battery pack (). A forked air passage () extends from an air inlet () and is defined between the inner case () and the outer case () and along the outer surface of the radiator plate () until reaching a pair of air outlets ().

Battery packs having improved heat radiation

A battery pack ( ) includes an outer enclosure ( ) and a forked air passage ( ) for introducing cooling air via the intake port ( ) formed in an outer enclosure ( ), sending the air between cell groups ( ) and ( ) which contain cells ( ), and discharging it from the outer enclosure at discharge ports ( ). Two metallic radiator plates ( ) partially define the air passage so as to be in contact with the side cells ( ), whereas a circular radiator plate ( ) made of synthetic resin also partially define the air passage so as to be in contact with the center cells ( ). The contact areas of the side cells with the metallic radiator plates ( ) are varied in order to achieve even cooling of the cells. The upstream portion of the synthetic resin radiator plate has a thicker wall than the downstream portion to achieve the same purpose.

Battery pack with an improved cooling structure

A battery pack ( ) has a double casing structure, including an inner case ( ) disposed inside an outer case ( ). The inner case ( ) includes a radiator plate ( ) that is in contact with the side walls of battery cells ( ) disposed within the battery pack ( ). A forked air passage ( ) extends from an air inlet ( ) and is defined between the inner case ( ) and the outer case ( ) and along the outer surface of the radiator plate ( ) until reaching a pair of air outlets ( ).

Battery pack with improved heat radiation and sealing

Battery pack

A simple attachment structure of the present invention ensures favorable connection of a battery pack with a battery holder in a power-driven tool over a long time period without causing any defective contact. A pair of side slots (47a,47b) as well as a pair of insertion slots (48a,48b) are formed in a connection surface (49) of an upper battery case (20) of a battery pack (10). Electrode terminal assemblies (41a,41b) are set in the side slots (47a,47b) and the insertion slots (48a,48b) to be exposed on the two side faces thereof. A positive spring terminal (64a) and a negative spring terminal (64b) are integrally joined with and supported by a terminal base 61 of a battery holder (60). Each spring terminal (64a,64b) has an insertion element (66a,66b) formed to have a width a little greater than the width of the insertion slot (48a,48b). When the spring terminals (64a,64b) are inserted into the insertion slots (48a,48b), the elasticity of the spring terminals (64a,64b) presses the insertion elements (66a,66b) thereof against the electrode terminal assemblies (41a,41b). This realizes electrical connection of the spring terminals (64a,64b) with the electrode terminal assemblies (41a,41b) and enables the battery pack (10) to be integrally joined with the battery holder (60) of the power-driven tool.

Growing community of inventors

Nagoya, Japan

Youichi Kato