Electric unit having capacitor
A PCU has an inside sealed by a case made of aluminum and a bottom plate. Interior space of the PCU accommodates an IPM, a control substrate, and a capacitor. The IPM is provided to abut an upper surface of the bottom plate. The control substrate is a rectangular plate having mounted thereon a control circuit including electronic components such as a gate driver, a transformer and the like, and is provided above the IPM. The capacitor is accommodated in a housing in a substantially parallelepiped form. A reflector made of aluminum of high thermal reflectivity and high thermal conductivity is provided on the entire lower surface of the capacitor.
1. An electric unit comprising:
a capacitor;
a casing for accommodating said capacitor;
an electronic component accommodated in said casing, generating heat by carrying out a function through electrical conduction; and
a reflector provided between said electronic component and said capacitor, and connected to said casing by at least one fastening member while abutting said capacitor, for reflecting heat radiated from said electronic component, wherein
said casing includes a first wall surface closer to said capacitor than said electronic component, and a second wall surface facing said first wall surface and being closer to said electronic component than said capacitor, and
said reflector is connected to said first wall surface of said casing by said at least one fastening member while abutting said capacitor.
2. The electric unit according to claim 1 , wherein
said first wall surface includes a plurality of projections each projecting toward an interior of said casing,
said capacitor is contained in space between said plurality of projections,
said at least one fastening member is a plurality of fastening members, and each of said plurality of fastening members are provided correspondingly to said plurality of projections, and
said plurality of fastening members are fastened to tip end portions of said plurality of projections with said reflector interposed therebetween, respectively, while abutting said reflector.
3. The electric unit according to claim 2 , wherein
seating surface portions formed to extend outward are provided on side surfaces of said capacitor correspondingly to said plurality of projections, and
said plurality of fastening members are fastened to tip end portions of said plurality of projections with said reflector and further said seating surface portions interposed therebetween, respectively.
4. The electric unit according to claim 1 , wherein
a material of high thermal reflectivity and high thermal conductivity is used as a material for said reflector.
5. The electric unit according to claim 1 , wherein
a coolant passage is provided on an outer side of said second wall surface.
6. The electric unit according to claim 5 , wherein
said electronic component is a semiconductor element abutting an inner side of said second wall surface.
7. The electric unit according to claim 5 , further comprising a semiconductor element abutting an inner side of said second wall surface, wherein
said electronic component is an electronic component mounted on a substrate provided on an inner side of said casing relative to said semiconductor element, for controlling said semiconductor element.