Electrical wiring device for vehicle

1. An electrical wiring device for vehicle, comprising:

an auxiliary connector to which a power supply line, a ground line, and a communication line for an in-vehicle network all mounted on a vehicle are connected; and

a distribution module detachably connected between one or more optional devices mounted on the vehicle and the auxiliary connector, disposed between the one or more optional devices and the auxiliary connector, and connected to the power supply line, the ground line, and the communication line via the auxiliary connector,

the distribution module comprising:

relays connected to the power supply line;

one or more communication interfaces;

one or more input/output interfaces configured to output first signals to the one or more optional devices;

a connecting terminal for connecting, on the optional device side of the distribution module closest to the one or more optional devices, an output of the one or more communication interfaces, outputs of the relays and outputs of the input/output interfaces to the one or more optional devices; and

a control unit configured to:

acquire second signals from the communication line via the one or more communication interfaces;

control the relays and the input/output interfaces based on the second signals acquired via the one or more communication interface interfaces; and

perform a fuse function for detecting an overcurrent in one or more of the relays on the basis of an electricity energizing current of each of the relays and an electricity energizing time of each of the relays, wherein

the control unit is configured to control operations of the relays and the input/output interfaces corresponding to the optional devices connected to the connecting terminal, and the distribution module is disposed between the auxiliary connector and the connecting terminal.

2. The electrical wiring device for vehicle of claim 1 , wherein

the control unit is configured to switch ON and OFF of each of the relays corresponding to vehicular signals acquired via the communication line.

3. The electrical wiring device for vehicle of claim 1 , wherein

the distribution module includes a voltage converter for converting a voltage supplied from the power supply line.

4. The electrical wiring device according to claim 1 , wherein the first signals comprise one of: detection signals and control signals.

5. The electrical wiring device according to claim 1 , wherein the relays comprise semiconductor relays.

6. The electrical wiring device according to claim 5 , wherein in performing fuse function, the control unit performs operations for each semiconductor relay comprising:

calculating a heat generation temperature and a heat radiation temperature of the respective semiconductor relay based on a current value flowing through the respective semiconductor relay and an electricity energizing time of the respective semiconductor relay;

estimating a temperature of the respective semiconductor relay based on an ambient temperature;

detecting an overcurrent in the respective semiconductor relay if the estimated temperature reaches a preset threshold temperature; and

shutting off the respective semiconductor relay if an overcurrent is detected.

7. The electrical wiring device according to claim 6 , wherein:

each of the semiconductor relays comprises a current sensor; and

in performing fuse function, the control unit performs operations for each semiconductor relay comprising estimating the temperature of the respective semiconductor relay based on a current value detected by the respective current sensor.

8. The electrical wiring device according to claim 1 , wherein the control unit comprises an integrated computer comprising a central processing unit (CPU) and a storage unit.

9. The electrical wiring device according to claim 1 , wherein the connecting terminal connects the outputs of the relays and the outputs of the input/output interfaces such that the second signals acquired from the communication line are output to the one or more optional devices from the distribution module as the first signals in response to a control operation from the control unit.