JP-2026075288-A - Core unit

Abstract

[Challenge] To improve the performance of the core unit while miniaturizing it and ensuring heat dissipation. [Solution] The core unit 10 comprises a core 20 having a through hole 21, a busbar 30 wrapped around the core 20, and a resin molded part 40 that insulates the core 20 and the busbar 30 and holds them together as a single unit. The core is formed in a cylindrical shape and has an inner surface 22 of the through hole 21, an outer surface 23, a front surface 24 connecting the inner surface 22 and the front edge of the outer surface, and a rear surface 25 connecting the inner surface 22 and the rear edge of the outer surface 23. The busbar 30 is arranged in the through hole 21 and has a first busbar 31 whose rear end 31C protrudes further back than the rear surface 25, a second busbar 32 whose front end 32B protrudes further forward than the front surface 24, and a third busbar 33 which is formed in a U shape along the rear surface 25, the outer surface 23 and the front surface 24 and connects the rear end 31C of the first busbar 31 and the front end 32B of the second busbar 32. A part of the third busbar 33 is a heat dissipation part 33A exposed from the resin molded part 40. [Selection Diagram] Figure 4

Inventors

• 岡本 昂大
• 木佛寺 宣博
• 山田 幸伯

Assignees

• 株式会社オートネットワーク技術研究所
• 住友電装株式会社
• 住友電気工業株式会社

Dates

Publication Date

20260508

Application Date

20241022

Claims (7)

1. A core having through holes, A busbar wrapped around the aforementioned core, A core unit comprising a resin molded portion that insulates and integrally holds the core and the busbar, The core is formed in a cylindrical shape extending in the front-rear direction and has an inner surface that constitutes the through hole, an outer surface positioned outside the inner surface, a front surface connecting the front edge of the inner surface and the front edge of the outer surface, and a rear surface connecting the rear edge of the inner surface and the rear edge of the outer surface. The busbar comprises a first busbar positioned in the through hole with its rear end protruding further back than the rear surface, a second busbar positioned in the through hole with its front end protruding further forward than the front surface, and a third busbar formed in a U-shape along the rear surface, the outer surface, and the front surface, connecting the rear end of the first busbar and the front end of the second busbar. A core unit in which a portion of the third busbar is a heat dissipation section exposed from the resin molded portion.
2. The core unit according to claim 1, wherein the core is formed integrally.
3. The core unit according to claim 1 or 2, wherein the resin molded portion exposes only the surface of the third busbar that does not face the core.
4. The core unit according to claim 1 or 2, wherein the busbars are formed by welding or bolting together the first busbar, the second busbar, and the third busbar.
5. The heat dissipation section is in contact with a heat dissipation resin plate. The core unit according to claim 1 or claim 2, wherein the resin plate is in contact with the housing.
6. The aforementioned resin plate has through holes formed therein for heat dissipation. The core unit according to claim 5, wherein an insulating sheet is disposed between the resin plate and the housing.
7. The resin molded portion includes a core case for housing the core, The core unit according to claim 1 or claim 2, wherein the core case has through holes for assembly through which the first busbar and the second busbar are inserted.

Description

This disclosure pertains to the core unit. Japanese Patent Publication No. 2017-212264 (Patent Document 1 below) discloses a noise filter comprising a magnetic core surrounding a conductive path, a case housing the magnetic core, and a heat transfer member interposed between the outer surface of the magnetic core and the inner surface of the case, having a thermal resistance lower than that of air. The conductive path consists of a wire harness formed by bundling multiple insulated wires. Japanese Patent Publication No. 2017-212264 Figure 1 is a perspective view of the core unit from an oblique angle above and in front.Figure 2 is a perspective view of the core unit from a diagonal downward and forward angle.Figure 3 is a perspective view of Figure 1 with the resin molded portion removed.Figure 4 is a side view of Figure 1 with the resin molded portion removed.Figure 5 is a side view of Figure 1 with the resin molded portion and magnetic core removed.Figure 6 is a front view of Figure 1 with the resin molded portion and magnetic core removed.Figure 7 is a cross-sectional view taken along line A-A in Figure 6.Figure 8 is a perspective view of Basba.Figure 9 is a cross-sectional view showing the internal structure of the core unit. [Description of Embodiments in this Disclosure] [1] The core unit of the present disclosure comprises a core having a through hole, a busbar wrapped around the core, and a resin molded portion that insulates and integrally holds the core and the busbar, wherein the core is formed in a cylindrical shape extending in the front-rear direction and has an inner surface constituting the through hole, an outer surface disposed outside the inner surface, a front surface connecting the front edge of the inner surface and the front edge of the outer surface, and a rear surface connecting the rear edge of the inner surface and the rear edge of the outer surface, the busbar comprises a first busbar disposed in the through hole with its rear end protruding rearward from the rear surface, a second busbar disposed in the through hole with its front end protruding forward from the front surface, and a third busbar formed in a U-shape along the rear surface, the outer surface and the front surface, and connecting the rear end of the first busbar and the front end of the second busbar, a part of the third busbar being a heat dissipation portion exposed from the resin molded portion. According to the above configuration, the core and busbar are held together by the resin molded part, thus ensuring insulation between the core and busbar while suppressing displacement of the busbar due to vibration. Furthermore, since a portion of the third busbar serves as a heat dissipation section, the core unit can be miniaturized while improving performance and ensuring heat dissipation. [2] In the above [1], it is preferable that the core is formed integrally. When a core is formed by combining a pair of split cores, EMC performance tends to degrade. With the above configuration, the core is a single unit, thus avoiding a degradation in EMC performance. [3] In the above [1] or [2], it is preferable that the resin mold portion exposes only the side of the third busbar that does not face the core. The above configuration allows for improved heat dissipation while minimizing busbar exposure. [4] In any of the above [1] to [2], it is preferable that the busbar is formed by welding or bolting together the first busbar, the second busbar, and the third busbar. According to the above configuration, when the busbar is formed by welding, bolt fastening locations are unnecessary, making it easier to miniaturize. On the other hand, when the busbar is formed by bolt fastening, the work is easier than welding. [5] In any of the above [1] to [4], it is preferable that the heat dissipation section is in contact with a heat dissipation resin plate, and the resin plate is in contact with the housing. With the above configuration, heat can be dissipated from the heat dissipation section to the housing via the resin plate. [6] In the above [5], it is preferable that the resin plate has through holes for heat dissipation and that an insulating sheet is placed between the resin plate and the housing. According to the above configuration, heat dissipation can be enhanced by through-holes for heat dissipation, while insulation between the housing and the heat dissipation sheet can be ensured. [7] In any of the above [1] to [6], the resin molded portion preferably comprises a core case for housing the core, and the core case has through holes for assembly through which the first busbar and the second busbar are inserted. With the above configuration, the assembly of the busbars can be improved by inserting the first busbar and the second busbar through the insertion holes in the core case. [Details of the embodiments of this disclosure] Embodiments of the present disclosure are described below. This disclosure is not limited to these ex