CN-122029948-A - Circuit unit

CN122029948ACN 122029948 ACN122029948 ACN 122029948ACN-122029948-A

Abstract

A circuit unit is disclosed, which suppresses the thermal influence of a pass circuit on a current sensor and the influence on a magnetic field. The circuit unit (10) is provided with a current sensor (12), a pass circuit (16) configured to include a detection conductor portion (14) for detecting a current value by the current sensor (12), and non-energized heat transfer members (20 a, 20 b) thermally connected to the pass circuit (16) and including heat transfer portions (18 a, 18 b) in contact with a heat dissipation object (26) in a thermally conductive manner.

Inventors

MORINO Shintaro
Ryuta Yasuji
Shi Benzao

Assignees

株式会社自动网络技术研究所
住友电装株式会社
住友电气工业株式会社

Dates

Publication Date: 20260512
Application Date: 20241004
Priority Date: 20231018

Claims (9)

1. A circuit unit is provided with: A current sensor; A pass circuit configured to include a detection conductor portion for detecting a current value by the current sensor, and And a non-energized heat transfer member thermally connected to the through-circuit and including a heat transfer portion in contact with the heat dissipation object in a heat-conductive manner.
2. The circuit unit of claim 1, wherein, The pass circuit has a pair of parallel portions extending from both sides of the extending direction of the detection conductor portion in parallel with the detection conductor portion in a direction away from the current sensor, The non-energized heat transfer member is thermally connected to the through-circuit on a base end portion side of at least one of the parallel portions.
3. The circuit unit of claim 2, wherein, The heat transfer portion of the non-energized heat transfer member is in contact with the heat radiation object on the current sensor side than the protruding end portion of the parallel portion.
4. A circuit unit according to claim 2 or 3, wherein, The current sensor includes a case accommodating the detection conductor portion, and a pair of terminal portions connected to the both sides of the detection conductor portion and protruding toward the both sides of the case, Each of the parallel portions of the through circuit and the non-energized heat transfer member is constituted by a bus bar made of a flat metal plate, The base end portions of the parallel portions are fastened to a pair of the terminal portions of the current sensor, respectively, and the non-energized heat transfer member is fastened to the terminal portions together with the base end portion of at least one of the parallel portions.
5. The circuit unit of claim 1, wherein, The pass circuit has a first crossing portion protruding from one end side of the detection conductor portion toward one side in the plate thickness direction of the detection conductor portion, and a second crossing portion protruding from the other end side of the detection conductor portion toward the other side in the plate thickness direction of the detection conductor portion, The non-energized heat transfer member is thermally connected to the through-circuit on a base end portion side of at least one of the first intersecting portion and the second intersecting portion.
6. The circuit unit of claim 5, wherein, At least one of the first intersecting portion and the second intersecting portion is provided with an energizing-side heat transfer portion that is in contact with the heat radiation object in a heat-conductive manner.
7. The circuit unit according to claim 5 or 6, wherein, The current sensor includes a case accommodating the detection conductor portion, and a pair of terminal portions connected to both sides of the detection conductor portion in an extending direction and protruding toward both sides of the case, The first and second intersecting portions of the through circuit and the non-energized heat transfer member are each constituted by a bus bar made of a flat metal plate, The base end portions of the first and second intersecting portions are fastened to a pair of the terminal portions of the current sensor, respectively, and the non-energized heat transfer member is fastened to the terminal portions together with the base end portion of at least one of the first and second intersecting portions.
8. The circuit unit of claim 1, wherein, The non-energized heat transfer member is provided integrally with the portion of the pass circuit.
9. The circuit unit according to claim 1 or 2, wherein, The circuit unit includes a case accommodating the current sensor, the through circuit, and the non-energized heat transfer member, the case constituting the heat dissipation object, The heat transfer portion of the non-energized heat transfer member is in contact with the housing in a heat-conductive manner.

Description

Circuit unit Technical Field The present disclosure relates to circuit units. Background Patent document 1 discloses a circuit unit mounted on a vehicle and disposed in a power supply path from a power source to a load. The circuit unit includes a current sensor for measuring a current flowing through a current path housed therein. With recent large current flows in vehicles, the amount of heat generated by the current flowing through the circuit increases, and there is a concern that the current sensor is thermally affected. Accordingly, in patent document 1, on both sides of a detection conductor portion of a current-passing circuit for detecting a current value by a current sensor, an extension portion bent in the same direction (downward) in a direction orthogonal to the detection conductor portion is provided, and a heat radiation path of a current-passing bus bar is ensured by thermally contacting a heat transfer portion provided on a distal end side of the extension portion with a heat radiation object. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2021-015959 Disclosure of Invention Problems to be solved by the invention However, when the through circuit is arranged in this way, noise due to enhancement of the magnetic field by the extension portions on both sides of the current sensor is likely to be generated, and malfunction of the current sensor is likely to be caused. Accordingly, a circuit unit is disclosed that suppresses the influence of the pass circuit on the heat of the current sensor and the influence on the magnetic field. Means for solving the problems The circuit unit includes a current sensor, a through circuit including a detection conductor portion for detecting a current value by the current sensor, and a non-energized heat transfer member thermally connected to the through circuit and including a heat transfer portion in contact with a heat dissipation object in a thermally conductive manner. Effects of the invention According to the circuit unit of the present disclosure, the influence of the heat of the current sensor and the influence of the magnetic field on the current sensor by the pass circuit can be suppressed. Drawings Fig. 1 is a longitudinal sectional perspective view of a circuit unit according to the first embodiment, and is a view showing a state in which a part of a housing is removed. Fig. 2 is a longitudinal sectional view partially showing the section II-II in fig. 1 enlarged. Fig. 3 is a longitudinal sectional perspective view of the circuit unit according to the second embodiment, and is a view showing a state in which a part of the housing is removed. Fig. 4 is a longitudinal sectional view partially showing the IV-IV section in fig. 3 enlarged. Fig. 5 is a perspective view schematically showing a modification of the circuit unit. Detailed Description < Description of embodiments of the invention > First, embodiments of the present disclosure will be described. The circuit unit of the present disclosure is provided with, (1) The heat sink comprises a current sensor, a conduction circuit including a detection conductor portion for detecting a current value by the current sensor, and a non-energized heat transfer member thermally connected to the conduction circuit and including a heat transfer portion in contact with a heat sink in a heat conduction manner. According to the circuit unit of the present embodiment, the non-energized heat transfer member is thermally connected to the through-circuit including the detection conductor portion sensed by the current sensor, and includes the heat transfer portion that is in contact with the heat dissipation object in a heat conduction manner. In this way, the non-energized heat transfer member can be disposed in a region different from the layout path of the through circuit, and the heat transfer portion of the non-energized heat transfer member can be brought into contact with the heat dissipation object in a heat conduction manner, thereby securing the heat dissipation path of the through circuit. Further, since the non-energized heat transfer member is non-energized, a magnetic field caused by energization is not generated, and the influence of the non-energized heat transfer member on the magnetic field of the current sensor is advantageously avoided or suppressed. Accordingly, even when a large current flows through the through-circuit, heat dissipation from the through-circuit can be promoted to suppress thermal influence on the current sensor, and even if a heat dissipation path of the non-energized heat transfer member is used, influence on the magnetic field of the current sensor can be suppressed. As the current sensor, any type of sensor including a core and a coreless sensor can be used as long as it is a magnetic field detection type sensor. (2) In the above (1), it is preferable that the conduction path has a pair of parallel portions extending from bo