A control unit includes: an input portion that receives the positional information of a vehicle; a calculation unit that generates a control signal for controlling an electromagnetic relay; and an output portion that outputs the control signal to the electromagnetic relay. The calculation unit determines whether a location region of the electromagnetic relay is a relay-freeze region, the location region being identified by the positional information of the vehicle, and, when the location region of the electromagnetic relay is a relay-freeze region, performs a freeze inhibiting process for preventing the electromagnetic relay from being frozen or defrosting the electromagnetic relay by opening and closing the electromagnetic relay and causing the electromagnetic relay to vibrate.

A control unit includes: an input portion that receives the positional information of a vehicle; a calculation unit that generates a control signal for controlling an electromagnetic relay; and an output portion that outputs the control signal to the electromagnetic relay. The calculation unit determines whether a location region of the electromagnetic relay is a relay-freeze region, the location region being identified by the positional information of the vehicle, and, when the location region of the electromagnetic relay is a relay-freeze region, performs a freeze inhibiting process for preventing the electromagnetic relay from being frozen or defrosting the electromagnetic relay by opening and closing the electromagnetic relay and causing the electromagnetic relay to vibrate.

This relay unit includes: a first bus bar; a relay electrically connected to the first bus bar; and an apparatus cover for covering the first bus bar and the relay. The apparatus cover includes: an upper member in a box shape having a covered upper end, the upper member having an opening formed in a lower end; and a lower member bonded to the upper member such that the opening of the upper member is covered with the lower member. The lower member is formed of a resin having heat conductivity that is higher than that of the upper member. The first bus bar is connected to the lower member via a first inner heat conductive sheet such that heat can be transferred to the lower member, said first inner heat conductive sheet being disposed between the first bus bar and the lower member.

This relay unit includes: a first bus bar; a relay electrically connected to the first bus bar; and an apparatus cover for covering the first bus bar and the relay. The apparatus cover includes: an upper member in a box shape having a covered upper end, the upper member having an opening formed in a lower end; and a lower member bonded to the upper member such that the opening of the upper member is covered with the lower member. The lower member is formed of a resin having heat conductivity that is higher than that of the upper member. The first bus bar is connected to the lower member via a first inner heat conductive sheet such that heat can be transferred to the lower member, said first inner heat conductive sheet being disposed between the first bus bar and the lower member.

In an electronic module for a vehicle including a case in which an electronic component such as a relay is mounted, the electronic module includes a discharge hole which discharges liquid contained in the case, and the discharge hole includes a peripheral edge of a predetermined dimension determined based on surface tension of the liquid.

In an electronic module for a vehicle including a case in which an electronic component such as a relay is mounted, the electronic module includes a discharge hole which discharges liquid contained in the case, and the discharge hole includes a peripheral edge of a predetermined dimension determined based on surface tension of the liquid.

A power distribution device has a resin part covering a portion of a power line and a portion of a signal line and having a switch adjacent to one surface of the resin part, and a cooling part disposed adjacent to a back surface of the resin part opposite to the one surface. The power line and the signal line each have, inside the resin part, a laid-out portion extending in a planar direction orthogonal to an arrangement direction in which the one surface and the back surface are arranged, and a led-out portion extending from the laid-out portion toward the one surface. The laid-out portion of the power line and the laid-out portion of the signal line are located in a projection area of the cooling unit projected in the arrangement direction, and are separated from each other and arranged in the arrangement direction.

A power distribution device has a resin part covering a portion of a power line and a portion of a signal line and having a switch adjacent to one surface of the resin part, and a cooling part disposed adjacent to a back surface of the resin part opposite to the one surface. The power line and the signal line each have, inside the resin part, a laid-out portion extending in a planar direction orthogonal to an arrangement direction in which the one surface and the back surface are arranged, and a led-out portion extending from the laid-out portion toward the one surface. The laid-out portion of the power line and the laid-out portion of the signal line are located in a projection area of the cooling unit projected in the arrangement direction, and are separated from each other and arranged in the arrangement direction.

A protection system for an electromagnetic relay mounted on a vehicle is configured to protect the electromagnetic relay from causing a coupling failure due to freezing of the electromagnetic relay. The system includes a temperature detector, a cooler, and a control unit. The temperature detector sequentially measures an ambient temperature of a location in which the electromagnetic relay is disposed and outputs information on a change in the ambient temperature. The cooler cools an electric power line coupled to a fixing terminal of the electromagnetic relay. The control unit activates the cooler to cool the electric power line in a case where the control unit determines that the electromagnetic relay has a possibility of freezing on the basis of the information on the change in the ambient temperature from the temperature detector.

Provided is an electrical connection box including a housing casing for housing a relay, and a heat transfer sheet for transferring heat from the relay to the housing casing, the electrical connection box including: a bus bar provided between a top surface and an inside surface that correspond to each other in the housing casing so as to oppose the top surface and the inside surface; a first holding portion protruding from the inside surface and holding the bus bar via the heat transfer sheet; and a second holding portion protruding from the top surface and holding the bus bar.