JP2011066239A - Ecu concentration housing box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify wiring to a power supply circuit, and at the same time, prevent a voltage drop of a power supply supplied to an ECU substrate, while retaining the function of the power supply circuit installed in a common circuit substrate of an ECU concentration housing box. <P>SOLUTION: A plurality of the ECU substrates and the common circuit substrate are housed in a single box, and the power supply circuit and the signal circuit are provided in the common circuit substrate; and one system of power source line and ground line are connected to the power supply circuit, and a communication line is connected to the signal circuit. A vehicle power supply status signal is received by the signal circuit via the communication line; a relay section provided in the power supply circuit is controlled according to the vehicle power supply status signal; and the power supply is supplied to each ECU substrate at a desired timing, and a current-limiting circuit is provided in the power supply circuit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ECU central storage box, and more particularly, simplifies wiring to an ECU central storage box that centrally stores a plurality of ECU boards (circuit boards of electronic control units) mounted on an automobile in a single storage box. To do.

As this type of ECU central storage box, the present applicant provides an ECU central storage box 100 shown in FIG. 4 in Japanese Patent Application Laid-Open No. 2007-48890.
The centralized ECU 100 accommodates a plurality of ECU boards 102 in a case 101 and a common circuit board 103 in which a shared circuit connected to the circuit of each ECU board 102 is formed. It is connected to the substrate 102 by a connection bus 104. The common circuit board 103 is provided with a power supply circuit 105 that connects a plurality of power supply lines (IGN, ACC, + B) and a ground line (GND) and includes an overvoltage protection circuit. The power supply circuit 105 is connected to each ECU board 102. Connected to the power circuit.

JP 2007-48890 A

  In the ECU centralized storage box 100 disclosed in Patent Document 1, power is supplied to a plurality of ECU boards 102 via a power supply circuit 105 provided on a common circuit board 103, and a Zener that is a relatively large protective component provided in the power supply circuit. Since the diodes are provided on the common circuit board 103 and the Zener diodes are not provided on the individual ECU boards 102, enlargement of the ECU board is suppressed.

However, as described above, the power supply circuit 105 of the common circuit board 103 includes a power supply line (IGN) for supplying ignition power, a power supply line (ACC) for supplying accessory power, and a power supply line (ACC) for supplying constant power. + B) is connected to the ground line (GND), and there are many connection wires, and there is room for improvement in terms of simplifying the wiring.
Further, the ECU central storage box 100 having the above-described configuration also has room for improvement in terms of preventing a voltage drop of the power supplied to the ECU board 102.

  The present invention simplifies the wiring to the power supply circuit while preventing the voltage drop of the power supplied to the ECU board while maintaining the function of the power supply circuit provided on the common circuit board of the ECU central storage box. It is an issue.

In order to solve the above problems, the present invention provides:
A plurality of ECU boards and a common circuit board are accommodated in one box,
A power circuit and a signal circuit are provided on the common circuit board,
One power line and a ground line are connected to the power circuit, and a communication line is connected to the signal circuit,
The signal circuit receives a vehicle power supply state signal via the communication line, controls a relay unit provided in the power supply circuit according to the vehicle power supply state signal, and supplies power to each ECU board at a required timing. Supply, and
An ECU central storage box is provided in which a current limiting circuit is provided in the power supply circuit.

  As described above, in the present invention, only one power supply line and ground line are connected to the power supply circuit of the common circuit board, and no power supply line for supplying an ignition power supply or an accessory power supply is connected. Instead, in the present invention, in the signal circuit of the common circuit board, the vehicle power supply state signal indicating the ON / OFF state of the ignition power supply or the accessory power supply is received via the communication line, and the vehicle power supply state signal is The relay unit provided in the power supply circuit is controlled. With this configuration, the ignition power supply and accessory power supply are supplied to the ECU board at a necessary timing without connecting a power supply line for supplying the ignition power supply and accessory power supply to the power supply circuit of the common circuit board as in the prior art. be able to. Therefore, according to the present invention, it is possible to reduce the number of electric wires connected to the power supply circuit while maintaining the function of the power supply circuit in the common circuit board, and to simplify the wiring.

  Further, as described above, by providing the current limiting circuit in the power circuit of the common circuit board, the ECU board connected to the common circuit board can be protected from overcurrent, and the voltage of the power supplied to the ECU board Descent can be prevented. As the current limiting circuit, for example, a circuit as shown in FIG. 3 in which an inverting differential amplifier circuit is formed using an operational amplifier can be used.

  The power supply circuit of the common circuit board is provided with an input protection circuit connected to the power supply line and the ground line, and a step-down circuit connected to the input protection circuit, and the relay unit is connected to the input protection circuit and the signal circuit. Preferably, the current limiting circuit is connected to the step-down circuit.

  As described above, by providing the input protection circuit in the power supply circuit of the common circuit board, each ECU board connected to the common circuit board can be protected from overcurrent and the voltage can be stabilized. In particular, in the present invention, since the number of electric wires connected to the input protection circuit is reduced, the size of the input protection circuit can be reduced.

  Further, as described above, by connecting a step-down circuit to the input protection circuit, it is possible to share a step-down circuit from each ECU board to a common circuit board. By the step-down circuit, for example, a voltage of 12V is set to 9V, 5V, The voltage can be stepped down to 3.3V or the like.

  Furthermore, by connecting the control unit of the signal circuit to the relay unit connected to the input protection circuit, the relay unit is controlled according to the vehicle power supply state decoded by the control unit, and 12V Ignition power and accessory power can be supplied to the ECU board at the required timing. Specifically, an accessory power supply relay and an ignition power supply relay can be connected to the input protection circuit as the relay unit, and an ASIC or CPU can be connected to the relays as the control unit.

  In addition, the voltage of the post-step-down line (for example, 5V) supplied to each ECU is used as a power source for a microcomputer, ASIC, or the like, so that a voltage drop is not allowed. Thus, a voltage drop in the post-buck line can be effectively prevented. Further, it is preferable that the current limiting circuit is connected to the control unit, and ON / OFF control according to a vehicle power source state such as an ignition power source or an accessory power source is performed by transistor voltage control in the current limiting circuit by the control unit.

The communication line connected to the signal circuit of the common circuit board is connected to, for example, a CAN communication line (CAN bus) that performs in-vehicle LAN communication by CAN (Controller Area Network).
In addition, it is not limited to a CAN communication line, You may connect to the communication line based on LIN (Local Interconnect Network) or Flex Ray.

  Further, when the signal circuit is connected to a plurality of CAN buses, it is preferable that a gateway is built in the ASIC or CPU which is a control unit of the signal circuit. Thereby, a gateway board | substrate can be reduced.

  As described above, according to the present invention, only one power line connected to the battery and the ground line are connected to the power circuit of the common circuit board, while the ignition circuit and the accessory power supply are connected in the signal circuit of the common circuit board. Since the vehicle power supply state signal indicating the ON / OFF state is received via the communication line and the relay unit provided in the power supply circuit is controlled according to the vehicle power supply state signal, the power supply of the common circuit board Even if a power supply line for supplying ignition power or accessory power is not connected to the circuit, ignition power or accessory power can be supplied from the common circuit board to the ECU board at a necessary timing. That is, it is possible to simplify the wiring by reducing the number of wires connected to the power supply circuit while maintaining the function of the power supply circuit on the common circuit board.

  Also, by providing a current limiting circuit in the power circuit of the common circuit board, the ECU board connected to the common circuit board can be protected from overcurrent, and a voltage drop of the power supplied to the ECU board can be prevented. Can do. In particular, as described above, by connecting the current limiting circuit to the step-down circuit, it is possible to share the step-down circuit from each ECU to the common circuit board, and to effectively prevent a voltage drop in the line after step-down. .

It is a block diagram which shows the whole structure of ECU concentration storage box of this embodiment. It is a block diagram which shows the circuit structure of a common circuit board. It is drawing which shows a current limiting circuit. It is a figure which shows a prior art example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show an embodiment of the present invention. The ECU centralized storage box 1 shown in FIG. 1 houses three ECU boards 3 (3A, 3B, 3C) and a common circuit board 4 in a box 2, and the ECU boards 3 (3A, 3B, 3C) and the common circuit board 4 are connected via a connection bus 5 (5a, 5b) made of a bus bar. The ECU board 3 (3A, 3B, 3C) is connected to a plurality of electrical equipment (not shown) and electrically controls them. In this embodiment, three ECU boards are accommodated, but the number is not limited to three, and may be two or four or more.

  Examples of the ECU board 3 include a smart ECU and a camera ECU, but the type of the ECU board is not limited to these.

The common circuit board 4 is provided with a power supply circuit 6 and a signal circuit 13.
As shown in FIG. 2, the power supply circuit 6 is provided with an input protection circuit 7 and inputs a power supply line (+ B) W1 connected to the positive electrode of the battery and a ground line (GND) W2 connected to the negative electrode of the battery. The protection circuit 7 is connected. Although not shown, the input protection circuit 7 is equipped with a Zener diode for voltage protection together with an electrolytic capacitor.
The power supply circuit 6 is provided with a step-down circuit 8 connected to the input protection circuit 7. In this embodiment, the voltage of 12V is stepped down to 5V by the step-down circuit 8, but the voltage is not limited to 5V and can be stepped down to a plurality of voltages.

  On the other hand, in the power supply circuit 6, relays 9 and 10 are mounted as a relay unit connected to the input protection circuit 7, and an ASIC 15 that is a control unit of the signal circuit 13 is connected to the relays 9 and 10. In this embodiment, an accessory power supply relay (ACC relay) 9 for turning on / off the output of the 12V accessory power supply and an ignition power supply relay (IG1 relay, IG2 relay) 10 for turning on / off the output of the 12V ignition power supply. (10a, 10b) are connected to the input protection circuit 7, and the ASIC 15 is connected to the accessory power supply relay 9 and the ignition power supply relay 10 (10a, 10b), respectively.

The 12V accessory power line and the 12V ignition power line connected to each ECU board 3 (3A, 3B, 3C) via the accessory power relay 9 and the ignition power relay 10 (10a, 10b), The protective fuses 11a and 11i are connected to each other, and the protective fuse 11b is also connected to the 12V constant power supply line connected to each ECU board 3 (3A, 3B, 3C) without going through a relay. .
If a semiconductor relay having a protection circuit (shutdown circuit) at the time of excess current is mounted as the accessory power supply relay 9 and the ignition power supply relay 10 (10a, 10b), the fuses 11a, 11i need not be provided. Good.

  Further, a current limiting circuit 12 as shown in FIG. 3 is provided in each post-step-down line for supplying power to the ECU board 3 (3A, 3B, 3C) with a voltage stepped down to 5V in the step-down circuit 8. The current limiting circuit 12 forms an inverting differential amplifier circuit using the operational amplifier 20, controls the transistor 21 with the output voltage of the operational amplifier 20, and controls the field effect transistor (FET) 22 with the transistor 21. The current is limited. For example, when the consumption current I1 is large, the voltage drop at the low resistance 23 is large, the output voltage of the operational amplifier 20, the base voltage of the transistor 21, and the collector-emitter current I2 is small, and a field effect transistor (FET). The gate-source voltage of 22 becomes small. As a result, the consumption current I1 is reduced, and the voltage drop of the low resistance 23 is reduced. Thereafter, the current is controlled to be constant by repeating the pattern in which the magnitudes are reversed. In the current limiting circuit 12, various resistance values are set so as to obtain a target current value.

  The current limiting circuit 12 only limits the current value (sets an upper limit value). When the circuit is interrupted, the current limiting circuit 12 can be interrupted by dropping the base voltage of the transistor 21 directly from the ASIC 15 through the line A to the ground. The output voltage of the operational amplifier 20 can be confirmed by the line B, and can be used for judgment of interruption. Further, in order to prevent a voltage drop in a short time until the current limiting circuit 12 operates, a momentary interruption occurs at the last stage of the step-down line that supplies 5V power to each ECU board 3 (3A, 3B, 3C). A protective capacitor 24 is provided.

  On the other hand, as shown in FIG. 2, the signal circuit 13 is provided with a CAN interface circuit 14, and a communication line W 3 connected to a CAN bus for performing in-vehicle LAN communication is connected to the CAN interface circuit 14. Although not shown, the CAN interface circuit 14 is provided with a coil and a transceiver.

Further, the signal circuit 13 is provided with the ASIC 15 that is connected to the CAN interface circuit 14 and is connected to the accessory power supply relay 9 and the ignition power supply relay 10 (10a, 10b) of the power supply circuit 6 as described above. . The ASIC 15 performs CAN arbitration, receives and decodes the vehicle power supply state signal indicating the ON / OFF state of the ignition power supply and the accessory power supply via the communication line W3, and according to the power supply state, the accessory power supply relay 9 and the ignition power supply The relay 10 (10a, 10b) is controlled.
In the present invention, the ASIC 15 is provided as the control unit, but a CPU may be provided instead of the ASIC.

  The 5V power supply, 12V constant power supply (+ B), 12V ignition power supply (IG1, IG2), and 12V accessory power supply (ACC) are connected to the ECU board 3 (3A, 3B, 3C) via the power supply line 5a constituting the connection bus 5. ). Information transmitted and received by the signal circuit 13 of the common circuit board 4 via the communication line W3 is transmitted to the CAN controller 16 (16B, 16C) of the ECU board 3 (3B, 3C) via the signal line 5b constituting the connection bus 5. ). In the present embodiment, two ECU boards 3B and 3C are CAN-connected, but the number of CAN boards to be CAN-connected is appropriately set according to the type of ECU board.

  As described above, the power supply circuit 6 and the signal circuit 13 are provided on the common circuit board 4, and only one power supply line W1 and the ground line W2 connected to the battery are connected to the input protection circuit 7 of the power supply circuit 6, while the signal is connected. The circuit 13 receives a vehicle power supply state signal indicating the ON / OFF state of the ignition power supply or accessory power supply via the communication line W3, and the ASIC 15 serving as a control unit is an accessory power supply serving as a relay unit according to the vehicle power supply state signal. The relay 9 and the ignition power relay 10 (10a, 10b) are controlled. Therefore, the ignition power supply (IG1, IG2) and the accessory power supply (ACC) are connected from the common circuit board 4 to the ECU board 3 (3A, 3A, 3C) without connecting the power supply line for supplying the ignition power supply or the accessory power supply to the input protection circuit 7. 3B, 3C) can be supplied at a necessary timing, and while maintaining the function of the power supply circuit 6 in the common circuit board 4, the number of wires connected to the input protection circuit 7 can be reduced and the wiring can be simplified. In addition, the size of the input protection circuit 7 can be reduced.

  Further, as described above, by connecting the current limiting circuit 12 to the step-down circuit 8, the step-down circuit 8 is made common to the common circuit board 4 from each ECU 3 (3A, 3B, 3C). An overcurrent to (3A, 3B, 3C) can be prevented, and a voltage drop in a post-step-down line that supplies 5V power to each ECU board 3 (3A, 3B, 3C) can be effectively prevented.

1 ECU centralized storage box 2 Box 3 (3A, 3B, 3C) ECU board 4 Common circuit board 5 Connection bus 6 Power supply circuit 7 Input protection circuit 8 Step-down circuit 9 Accessory power supply relay 10 (10a, 10b) Ignition power supply relay 11 Fuse 12 Current limiting circuit 13 Signal circuit 14 CAN interface circuit 15 ASIC
16 CAN controller W1 Power line W2 Ground line W3 Communication line

Claims (2)

A plurality of ECU boards and a common circuit board are accommodated in one box,
A power circuit and a signal circuit are provided on the common circuit board,
One power line and a ground line are connected to the power circuit, and a communication line is connected to the signal circuit,
The signal circuit receives a vehicle power supply state signal via the communication line, controls a relay unit provided in the power supply circuit according to the vehicle power supply state signal, and supplies power to each ECU board at a required timing. Supply, and
An ECU central storage box, wherein a current limiting circuit is provided in the power supply circuit.   The power supply circuit of the common circuit board is provided with an input protection circuit connected to the power supply line and the ground line, and a step-down circuit connected to the input protection circuit, and the relay unit is connected to the input protection circuit and the signal circuit. The ECU central storage box according to claim 1, wherein the ECU is connected to the control unit and the current limiting circuit is connected to the step-down circuit.

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