JP3435699B2 - Vehicle load control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load control device for a vehicle, which operates a load such as a drive motor for a wiper or a power window arranged in each part of a vehicle or an indicator lamp used for an instrument panel. is there.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Laid-Open No. 63-74338, a load control for a vehicle which operates a load such as a drive motor or an indicator lamp based on data received through a communication line. The device is known.

In this vehicle load control device, a relay or a transistor is connected to the load, and an electric current is supplied from an output portion of the load control device to the relay or the transistor to turn on the relay or the like to operate the load. I was trying to let it.

[0004]

By the way, in the above-mentioned vehicle load control device, since the relays or transistors are uniformly connected to the load, the current supplied from the output part of the load control device is reduced. However, the relays or transistors are required for the number of loads, resulting in an increase in the number of parts, and in addition, it takes time and effort for wiring these.

On the other hand, it is possible to operate by directly connecting a load to the output terminal of the output section, but in order to reliably operate a load such as a drive motor which consumes a large amount of current, a large current is output from the output section. Need to supply. For this reason,
It is necessary to increase the current capacity of the output section, resulting in an increase in cost.

Further, the current capacity of only the output terminal to which a load with a large current consumption is connected is increased, and the current capacity of the output terminal to which a load with a small current consumption is connected is reduced to suppress the current capacity of the entire output section. However, in this case, it is necessary to design the circuit configuration of the output section according to the load connected to the load control device, and the circuit configuration differs for each load control device. There is a problem that it becomes impossible to standardize the units.

An object of the present invention is to solve the above problems and to provide a vehicle load control device which is inexpensive and has no waste of parts.

[0008]

In order to achieve the above object, the present invention provides a communication means for performing data communication via a communication line, and currents to a plurality of output terminals according to data received by the communication means. and current output means for outputting a power supply line
A load control unit internally connected to the vehicle power supply via the power supply unit for supplying a large current, and to the load control unit, a small load connected to the output terminal and operating with a small current And the load control unit
A large load part connected to the power supply means in the unit and operating with a large current, and a switch means for turning on / off the current from the power supply means to the large load part according to the output current from the output terminal. It is provided. In the vehicle load control device, it is preferable that a supply terminal that connects the heavy load section to the power supply unit is provided and that the number of the output terminals is set larger than the number of the supply terminals.

[0009]

According to the vehicle load control device having the above structure, data communication is performed through the communication line, and the current output means outputs a current in accordance with the received data. Then, the small load part which operates with a small current is directly operated by the output current from the output terminal of the current output means, while the large load part which operates with a large current has the switch means output from the output terminal of the current output means. By being turned on in response to a current, it is operated in accordance with the current flowing from the power supply means.

[0010]

FIG. 1 is a block diagram showing an embodiment of a vehicle load control device according to the present invention. The load control device includes a central control unit (CPU) 2, a multiplex communication circuit (communication means) 3, an output circuit (current output means) 4, and a constant voltage circuit (power supply means) 5, a load control unit 1, and an instrument panel. Small load part R operated by a small current such as an indicator light used for
L, a large load portion RH operated by a large current such as a drive motor such as a wiper and a power window, and a transistor Q as a switch means for driving the large load portion RH.

A plurality of switches 21 are connected to the CPU 2, and by inputting ON and OFF signals from these switches 21, switch data according to the ON and OFF signals and a destination of this data (others) The instruction data for instructing the load control unit 1) is output from the CPU 2 in parallel to the multiplex communication circuit 3.
Further, the CPU 2 is configured to output a control signal to the output circuit 4 based on the data from the other load control unit 1 received via the multiplex communication circuit 3.

The multiplex communication circuit 3 is connected to the multiplex communication circuit 3 of another load control unit 1 via communication lines M1 and M2. Then, the multiplex communication circuit 3 converts the parallel data from the CPU 2 into serial data and converts the parallel data into the communication line M.
1 and M2, and another load control unit 1
CP from serial data from
It is designed to output to U2. Note that the multiplex communication circuit 3 can continue communication with another load control unit 1 by sending the same data to the communication lines M1 and M2 even if either of the communication lines M1 and M2 is disconnected. It is like this. This improves the safety of communication.

The output circuit 4 turns on / off the output of current to the output terminals 41 to 43 in response to a control signal from the CPU 2. The output terminals 41 to 43 are connected to the small load section RL or the base of a transistor for driving the large load section RH.
The output current of the output circuit 4 is equal to the small load portion RL.
The current is set to be slightly higher than the current consumption of. As a result, the output current capacity of the output circuit 4 is reduced to the output terminals 41 to 41.
It can be made smaller than when the large load portion RH is directly connected to 43 and operated.

The constant voltage circuit 5 is connected to the vehicle battery B via a power line L, converts the voltage of the battery B into a predetermined voltage, and supplies the power from the battery B to the CPU 2 and the multiplex communication circuit 3. And the output circuit 4 and the supply terminals 51 and 52. Supply terminal 51,
The heavy load part RH is connected to 52, and the heavy load part R is connected.
A sufficient current to operate H is supplied to the supply terminals 51, 52.
It is designed to be supplied via.

Next, the operation of the load control device will be described. The base of the transistor Q that drives the large load portion RH is connected to the output terminal 41 of the load control unit 1, and the small load portion RL is connected to the output terminal 43.

When a current is output from the output terminal 41 and supplied to the base of the transistor Q, for example, according to data from the other load control unit 1 and the like, the transistor Q is turned on and the output terminal 41 transfers to the heavy load section RH. A current flows, and the large load parts RH are activated.

On the other hand, when a current is output from the output terminal 43 according to the data from the other load control unit 1 or the like, a current flows directly from the output terminal 43 to the small load portion RL,
This current activates the small load section RL.

As described above, the small load portion R having a small current consumption
Since the small load portion RL can be directly operated by connecting L to the output terminals 41 to 43 by the current from the output circuit 4, transistors are uniformly connected to the small load portion RL or the large load portion RH. It is possible to reduce the number of parts of the transistor as compared with the case where the small load part RL and the large load part RH are operated via the transistor. Also,
The output current capacity of each output terminal 41 to 43 of the output circuit 4 is
Since the load can be reduced uniformly regardless of the current consumption of the connected load, the circuit configuration of the load control unit 1 arranged in each part in the vehicle can be made common.

Although a transistor is used to drive the heavy load section RH in the above embodiment, a large load section RH is used by using a relay or a field effect transistor (FET).
May be driven.

[0020]

According to the present invention, the small load portion having a small current consumption is operated by the current from the current output means, and the large load portion having a large current consumption is operated through the switch means. The number of parts can be reduced compared to the case where the load is operated via the switch means. Further, the output current capacity of each output terminal of the current output means can be uniformly reduced regardless of the current consumption of the load connected to the load control unit, and the load control unit can be shared.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of a vehicle load control device according to the present invention.

[Explanation of symbols]

1 Load Control Unit 2 Central Control Section 3 Multiplex Communication Circuit (Communication Means) 4 Output Circuit (Current Output Means) 5 Constant Voltage Circuit (Power Supply Means) 41-43 Output Terminals 51, 52 Supply Terminal B Vehicle Battery (Vehicle Power Supply) ) L power line M1, M2 communication line Q transistor (switch means) RL small load part RH large load part

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Claims (2)

(57) [Claims] 1. A communication means for performing data communication via a communication line, a current output means for outputting a current to a plurality of output terminals according to data received by the communication means, and a power supply line.
A load control unit internally connected to the vehicle power supply via the power supply unit for supplying a large current, and to the load control unit, a small load connected to the output terminal and operating with a small current And the load control unit
A large load part connected to the power supply means in the unit and operating with a large current, and a switch means for turning on / off the current from the power supply means to the large load part according to the output current from the output terminal. A load control device for a vehicle, which is provided. 2. Supply terminal for connecting heavy load to power supply
And the output above the number of supply terminals
The number of terminals is set to be large, and the number of terminals is set to be large.
Load control device for vehicle.