JP2564558B2 - Vehicle electrical component control device - Google Patents

Description

The present invention relates to a vehicle electrical component control device.

(Prior Art) In recent automobiles, the operating state of the engine itself (air-fuel ratio,
A number of electronic controls ranging from the engine control unit that electronically controls ignition timing, idle speed, EGR, etc. to automatic transmission control units, air conditioner (air conditioner) control units, audio control units, and even navigation control units. Unit (so-called EC
U) is to be installed. Each of these electronic control units is normally a random access memory (RA
A rewritable data memory such as M) is provided, and the control parameters once stored in the memory are read out again and used.

This data memory is read-only memory (ROM)
Unlike the above, usually, in order to retain the once-stored data, it is necessary to constantly supply a predetermined power supply voltage, and the stored data disappears once the power is turned off (volatility). )have.

Therefore, in a vehicle equipped with a plurality of electronic control units (electronic control units) as described above, the total voltage of all the electronic control units is common to all the electronic control units as disclosed in Japanese Utility Model Laid-Open No. 61-92143, for example. A constant-voltage power supply circuit that considers the capacity is attached, and regardless of whether the ignition key switch is ON or OFF, the large-capacity constant-voltage power supply circuit always supplies backup voltage independently to multiple electronic control units. It had been.

(Problems to be Solved by the Invention) However, in the case of the above-mentioned prior art, the single constant-voltage power supply circuit is provided, and therefore the rating is inevitably large.
Further, since the configuration is not a constant-voltage power supply circuit dedicated to backup, the power consumption itself is considerably high when stepping down, so that battery exhaustion becomes a problem especially when the ignition key switch is OFF (alternate OFF).

(Means for Solving Problems) The present invention has been made for the purpose of solving the above problems, and in a vehicle provided with a plurality of electronic control units requiring a backup power source, the plurality of electronic control units are provided. A constant voltage power supply circuit is provided in each of the control units, and when the ignition key switch of the power supply system corresponding to each electronic control unit is turned off, the electronic control unit of any one of the plurality of electronic control units is selected. A backup voltage is supplied to other electronic control units by using a constant voltage power supply circuit.

(Operation) According to the above means, the ignition key switch
At the time of OFF, the backup voltage is supplied using the constant voltage power supply circuit of any specific electronic control unit,
Since the capacity of the constant voltage power supply circuit itself used is small, the power consumption is inevitably small.

(Embodiment) FIG. 1 shows a vehicle electrical component control device according to a first embodiment of the present invention.

In the figure, reference numerals 1 to 4 are first to fourth electronic control units for automobiles, for example, the first electronic control unit.
The electronic control unit 1 is an engine control unit, the second electronic control unit 2 is an automatic transmission control unit, the third electronic control unit 3 is an air conditioner control unit, and the fourth electronic control unit 4 is an audio control unit.

The first electronic control unit 1 is mainly composed of a CPU,
A microcomputer 10 including each of AM and ROM and I / O ports, and the microcomputer 10
And a first constant voltage power supply circuit 11 for supplying a backup voltage of 5 (V), for example.

The output terminal of the first constant voltage power supply circuit 11 is the backup power supply input terminal of the microcomputer 10, and the other input terminal is the positive electrode of the car battery 5 which is the main power supply of the vehicle via the power supply line 8. It is connected.

On the other hand, reference numeral 6 is an ignition key switch,
The movable side terminal 6c of the ignition key switch 6 is also connected to the positive electrode of the car battery 5.

Further, the second to fourth electronic control units 2 to 4 are
Second to fourth microcomputers 2 similar to those described above, each of which is composed mainly of a CPU and includes a RAM and a ROM
0, 30, 40 and second to fourth constant voltage power supply circuits 22, 33, 44, the second to fourth constant voltage power supply circuits 2
2, 33 and 44 each have a voltage supply configuration different from that of the first constant voltage power supply circuit 11. That is, first, the input terminals of the second and third constant voltage power supply circuits 22 and 33 are connected to the IG contact 6b of the ignition key switch 6 via the second and third operating voltage supply lines 200 and 300, respectively.
The input terminals of the fourth constant voltage power supply circuit 44 are connected to the ACC contacts 6a of the ignition key switch 6 through the fourth operating voltage supply line 400, respectively, and the second and third constant voltage power supplies are connected. Circuits 22 and 33 are normally connected to the IG contact O
When the IG voltage 12 (V) at the time of N is stepped down to 5 (V), it is connected to the memory power supply terminals of the second and third microcomputers 20 and 30, and the fourth constant voltage power supply circuit 44 is the ignition key. The ACC voltage 12 (V) of the switch 6 is stepped down to 5 (V) and then supplied to the memory power supply terminal of the microcomputer 40.

On the other hand, the second to fourth output side of the constant voltage power supply circuit 22,33,44 each b-contact type first through third relay switch LS ₁ ~ to the output side of the first constant-voltage power supply circuit 11 They are connected via a backup power supply line 7 provided via LS ₃ , and when the first to third relay switches LS _{1 to} LS ₃ are made, the first power supply via the backup power supply line 7 is used. The constant voltage power supply circuit 11 supplies the backup power of 5 (V). The symbols L _{1 to} L ₃ are relay coils provided corresponding to the _first to third relay switches LS _{1 to} LS ₃ , and the first to third relay coils L _{1 to} L ₃ are , The second to fourth operating voltage supply lines
It is connected corresponding to 200, 300, 400 respectively.

Therefore, in the above configuration, when the ignition key switch 6 is operated in the IG / ON state, the first to third electronic control units 2 to 4 of the second to fourth electronic control units 2 to 4 are operated.
The relay coils L _{1 to} L ₃ are broken by the IG voltage 12 (V) and maintained in the OFF state, and the second to fourth constant voltage power supply circuits 22, 33 and 44 keep the IG voltage 12 (V). After reducing the voltage to 5 (V), the second to fourth microcomputers 20, 30,
Supply to 40.

On the other hand, first, the ignition key switch 6 is completely turned off (IG contact OFF and ACC contact OFF), or AC
Only C contact 6a is ON, that is, at least IG contact 6b
When is turned off, the first and second relay coils L ₁ and L ₂ are in the non-excited state, so the first and second relay switches LS ₁ and LS ₂ are turned on and turned on. The backup voltage 5 (V) is supplied from the first constant voltage power supply circuit to the second and third microcomputers 20 and 30 via the backup power supply line 7. In this case, if the ACC contact 6a is also OFF in the same manner, the third relay coil L ₃ is also in the non-excited state, and the corresponding third
Since the relay switch LS _{3 of 1} is made and turned on, the backup voltage is also supplied from the first constant voltage power supply circuit 11 to the fourth microcomputer 40.
As a result, in the present embodiment, when the ignition key switch 6 is OFF, the first to fourth plurality of electronic control units 1 are
Constant voltage power supply circuit of a specific electronic control unit 1
By using 11 to supply the backup voltage,
Constant voltage power supply circuit of other electronic control units 2 to 4, 22, 33, 44
You don't have to use. Therefore, the power consumption of the car battery 5 can be saved accordingly. Also, the constant voltage power supply circuit 11 of the specific electronic control unit 1 used above
In principle, is suitable for a single electronic control unit, so a relatively small rating can be used in time. In addition, the wiring is easier and the voltage drop is smaller than in the case where the low-voltage power supply line is routed by many wire harnesses.

Further, if the specific electronic control unit can be arbitrarily switched and selected, another unit can be substituted even when the constant voltage power supply circuit of the specific electronic control unit fails. , The backup function is improved.

In the case of the first embodiment, the power system (IG system,
The backup power supply lines 7A (ACC) and 7B are the same as those described above for each power supply system, as shown in FIG. 2 as the second embodiment. (IG) may be provided independently. Even with such a configuration, it is of course possible to obtain the same operational effects as in the case of the above-described first embodiment, and in the configuration of the present embodiment, wiring can be performed separately for the power supply systems ACC and IG, so wiring work becomes easier. . Also, the operation timing is common. In FIG. 2, suffixes A are shown for the ACC power system and B for the IG power system.

Further, in the case of the first embodiment, relays are made to the second to fourth electronic control units 2 to 4 which do not use the constant voltage power supply circuit among the first to fourth electronic control units 1 to 4. By installing the coils L _{1 to} L ₃ and the relay switches LS _{1 to} LS ₃ individually, the backup voltage is supplied from the constant voltage power supply circuit 11 of the first electronic control unit 1 at the time of IG / OFF or ACC / OFF. However, this can be simplified, for example, as shown in FIG. 3 as the third embodiment.

That is, the relay coil L and the relay switch LS similar to the above are provided only on the first electronic control unit 1 side,
The reverse relay switch LS is commonly connected to the output sides of the second to fourth constant voltage power supply circuits 22, 33, 44 via the backup power supply line 7 and the relay switch LS is turned on at the time of IG / OFF.
In this case, the backup voltage can be supplied to the microcomputers 20, 30, 40 of the second to fourth electronic control units 2 to 4 just as in the case of the first embodiment. Moreover, according to such a configuration, the relay coil,
Since one relay switch is sufficient for each, there are advantages that the configuration is simple and the cost is low.

(Effects of the Invention) As described above, the present invention provides a vehicle having a plurality of electronic control units requiring a backup power supply, in which a constant voltage power supply circuit is provided in each of the plurality of electronic control units, When the ignition key switch of the power supply system corresponding to each electronic control unit is turned off, the constant voltage power supply circuit of any one of the above electronic control units is used to control other electronic control units. It is characterized in that a backup voltage is supplied to the unit.

That is, according to the present invention, since the backup voltage is supplied by using the constant voltage power supply circuit of any specific electronic control unit when the ignition key switch is turned off, the capacity of the constant voltage power supply circuit itself used is small. Therefore, power consumption is inevitably small.

Therefore, even when the ignition key switch is turned off, it is not necessary to take special measures against battery exhaustion.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a vehicle electric component control device according to a first embodiment of the present invention, and FIG. 2 is an electric circuit diagram of a vehicle electric component control device according to a second embodiment of the present invention. FIG. 3 is an electric circuit diagram of a vehicle electrical component control device according to a third embodiment of the present invention. 1 ... 1st electronic control unit 2 ... 2nd electronic control unit 3 ... 3rd electronic control unit 4 ... 4th electronic control unit 5 ... Car battery 6 ... Ignition key switch 7 ... Backup power supply line 8 ... Power supply line 10 ... First microcomputer 11 ... First constant voltage power supply circuit 20 ... Second microcomputer 22 ... Second constant voltage power supply circuit 30 ... Third Microcomputer 33 ...... Third constant voltage power supply circuit 40 ...... Fourth microcomputer 44 ...... Fourth constant voltage power supply circuit L ₁ ...... First relay coil L ₂ ...... Second relay coil L ₃ ...... Third relay coil LS ₁ ...... First relay switch LS ₂ ...... Second relay switch LS ₃ ...... Third relay switch L ...... Relay coil LS ...... Relay switch

Claims (1)

(57) [Claims] 1. A vehicle provided with a plurality of electronic control units requiring a backup power supply, wherein each of the plurality of electronic control units is provided with a constant voltage power supply circuit, and an ignition of a power supply system corresponding to each of the electronic control units. When the key switch is turned off, the backup voltage is supplied to the other electronic control units by using the constant voltage power supply circuit of one of the electronic control units specified above. An electric component control device for a vehicle, comprising: