| 摘要 |
PROBLEM TO BE SOLVED: To reduce the weight of a housing of a control device and improve heat radiation property in an ECU integrated electric power steering device in which the control device is fixed to a gear box.SOLUTION: A gear box 4 in which a reduction gear is stored is made of a material having a high thermal conductivity. The housing of a control device 3 is fixed to the gear box 4 and an electronic component including a heat generating element 311 is surface-mounted on a circuit board 31. The housing of the control device 3 includes a case 321 which stores the circuit board 31 and covers a surface on a side in which the heat generating element 311 of the circuit board 31 is installed and a cover 322 which covers a surface on an opposite side of the side covered with the case 321 of the circuit board 31. The case 321 includes a plate-like section 321c which is in contact with a mounting surface 46a of the control device 3 formed in the gear box 4. A high thermal conductivity metal plate 323 is fixed to the position of the plate-like section 321c on an internal surface of the case 321 made of a high thermal conductivity resin, and the heat generating element 311 is in contact with the high thermal conductivity metal plate 323.SELECTED DRAWING: Figure 3 |
