JP2014007791A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device that appropriately protects a DC/DC converter from an overcurrent or overheat anomaly.SOLUTION: A vehicular power supply device 1 having one or more DC/DC converters 50 for converting an output voltage of a power supply to feed loads, and a series circuit of a fuse 22 disposed between the DC/DC converter 50 and the load 23 and a protection switch 21 for protecting the fuse 22 includes: detection means 81 for detecting a current value through the protection switch 21; and a casing 100 housing the DC/DC converter 50, a bypass switch 40, the protection switch 21, the fuse 22 and the detection means 81. The protection switch 21 is configured to be turned off if the current value detected by the detection means 81 is outside a predetermined range.

Description

  The present invention relates to a power supply apparatus including a DC / DC converter that converts an output voltage of a power supply and supplies the converted voltage to a load.

  There are an increasing number of idle stop vehicles that stop the engine idling when the vehicle is stopped and improve fuel efficiency. In such a vehicle, the alternator (on-vehicle generator) is stopped at the time of idling stop, and the voltage is lowered because the power source is only the battery. Therefore, there is a vehicle in which a power supply device that boosts the power supply voltage by a DC / DC converter is mounted and the DC / DC converter is operated at an idle stop.

  In such a vehicle, in order to protect a load and an electric wire included in the vehicle, for example, a parallel circuit of a DC / DC converter and a bypass switch, a fuse and a fuse are provided between an alternator and a battery as a vehicle-mounted power source and the load. A series circuit of protection switches to be protected is connected in series.

  The power supply device described in Patent Document 1 includes a booster circuit and a relay function and / or fuse means in a relay case, thereby realizing a reduction in the size of the device and a reduction in the number of fuses mounted on the vehicle. .

JP 2008-101590 A

  In the conventional power supply device as described above, even if the bypass switch, the DC / DC converter, and the protection switch are housed in one housing, the protection switch protects only the fuse in the event of an abnormality due to overcurrent or overheating. It is carried out. For this reason, there is a problem in that an appropriate response cannot be unified uniformly between the protection switch and the DC / DC converter side when an abnormality occurs due to overcurrent or overheating.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a power supply apparatus that appropriately protects a DC / DC converter from an abnormality caused by overcurrent or overheating.

  A power supply apparatus according to the present invention includes one or more DC / DC converters that convert an output voltage of a power supply and supply the load to a load, a fuse provided between the DC / DC converter and the load, and the fuse A power supply device comprising a series circuit of protection switches to be protected, a detection means for detecting a current value flowing through the protection switch, and a casing that houses the DC / DC converter, the protection switch, a fuse, and the detection means The protection switch is configured to be turned off when the current value detected by the detection means is out of a predetermined range.

In the power supply device of the present invention, the detection means detects the current value flowing through the protection switch, and the protection switch is turned off when the current value detected by the detection means is out of a predetermined range. The case houses a DC / DC converter, a bypass circuit, a switch, a detection unit, a determination unit, and a fuse.
Thereby, when the value of the current flowing through the protection switch is out of the predetermined range, the protection switch is turned off, so that the protection of the DC / DC converter can be ensured.

  The power supply apparatus according to the present invention further includes a measuring unit that is housed in the casing and measures the temperature of the DC / DC converter, and the protection switch is turned on when the temperature measured by the measuring unit is higher than a predetermined temperature. Is configured to be turned off.

In the power supply device of the present invention, the measuring means measures the temperature of the DC / DC converter, and the protection switch is turned off when the measured temperature is higher than a predetermined temperature.
Thereby, when the temperature of the DC / DC converter is higher than the predetermined temperature, the value of the current flowing through the DC / DC converter is lowered or cut off, so that the protection of the DC / DC converter can be ensured. it can.

  Moreover, the power supply device according to the present invention is such that the protection switch is a semiconductor relay having the detection means, and includes a processor that drives and controls the semiconductor relay based on a current value given from the detection means. Features.

In the power supply device of the present invention, the processor drives and controls the protection switch configured as a semiconductor relay based on the current value given from the detection means.
As a result, since the current is cut off or the current value is reduced by the semiconductor relay driven by the processor, the protection of the DC / DC converter can be restored and the protection of the fuse can be realized.

  Further, the power supply device according to the present invention is characterized in that the protection switch is a semiconductor relay having the measurement unit, and includes a processor that drives and controls the semiconductor relay based on a temperature given from the measurement unit. And

In the power supply device of the present invention, the processor drives and controls the protection switch configured as a semiconductor relay based on the temperature given from the measuring means.
As a result, since the current is cut off or the current value is reduced by the semiconductor relay driven by the processor, the protection of the DC / DC converter can be restored and the protection of the fuse can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the power supply device which protects a DC / DC converter appropriately from the abnormality by overcurrent or overheating is realizable.

It is a circuit diagram which shows the principal part structure of embodiment of the power supply device which concerns on this invention. It is a circuit diagram which shows the detailed structure of the power supply device for vehicles. It is a timing chart which shows on / off operation of a bypass switch and a protection switch with which a power supply device for vehicles is provided.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

  FIG. 1 is a circuit diagram showing a main configuration of an embodiment of a power supply device according to the present invention. 1 includes a vehicle power supply device 1, a fuse box 2, a fuse box 3, a battery 91, an alternator 92, loads 23a, 23b, 23c, 23d, 23e, and 23f. The fuse box 2 includes protection switches 21e and 21f, fuses 22e and 22f, and a control unit 29. The protection switches 21e and 21f are semiconductor relays such as IPD (Intelligent Power Device). The fuse box 3 stores fuses 31a, 31b, 31e, and 31f.

  FIG. 2 is a circuit diagram showing a detailed configuration of the vehicle power supply device 1. The vehicle power supply device 1 includes a voltage conversion unit 10, a protection switch 21a, a protection switch 21b, a protection switch 21c, a protection switch 21d, a fuse 22a, a fuse 22b, a control unit 19, and a housing 100. Each part except for the housing 100 is housed in the housing 100. The voltage conversion unit 10 includes a DC / DC converter 50a, a DC / DC converter 50b, a bypass switch 40a, and a bypass switch 40b.

  The protection switches 21a, 21b, 21c, and 21d are semiconductor relays such as IPD. The protection switch 21a includes current value detection means 81a and temperature measurement means 82a, and the protection switch 21b includes current value detection means 81b, The protection switch 21c includes a current value detection unit 81c and a temperature measurement unit 82c. The protection switch 21d includes a current value detection unit 81d and a temperature measurement unit 82d.

  The positive electrode of the battery 91 and the alternator 92 (hereinafter referred to as “vehicle power supply 9”) is connected to one terminal of each of the bypass switch 40a and the DC / DC converter 50a through the fuse 31a, and is also connected to the bypass switch through the fuse 31b. 40b and the DC / DC converter 50b are respectively connected to one terminal.

  The other terminals of the bypass switch 40a and the DC / DC converter 50a are connected to the load 23a through the protection switch 21a and the fuse 22a, and are connected to the load 23c through the protection switch 21c and the fuse 22c. The other terminals of the bypass switch 40b and the DC / DC converter 50b are connected to the load 23b through the protection switch 21b and the fuse 22b, and are connected to the load 23d through the protection switch 21d and the fuse 22d.

  The positive electrode of the in-vehicle power supply 9 is also connected to the load 23e through the fuse 31e, the protection switch 21e, and the fuse 22e, and is connected to the load 23f through the fuse 31f, the protection switch 21f, and the fuse 22f.

  The load 23a is an accessory load (radio or the like), and the load 23b is an IG load (air conditioner, power window, or the like) that can be activated by an ignition key signal.

  The current value detection means 81a detects the current value flowing through the protection switch 21a. The temperature measuring unit 82a measures the temperature of the protection switch 21a. The current value detection means 81b detects the current value flowing through the protection switch 21b. The temperature measuring unit 82b measures the temperature of the protection switch 21b.

  The control unit 19 acquires the current value detected by the current value detection unit 81a, and turns off the protection switch 21a when the acquired current value is out of a predetermined range.

Since the protection switch 21a provided downstream is housed in the DC / DC converter 50a and the single casing 100, the control unit 19 can execute the current cutoff by the protection switch 21a, and more firmly. The DC / DC converter 50a can be protected.
Note that the value of the current flowing through the DC / DC converter 50a can be reduced by turning on the bypass switch 40a instead of turning off the protection switch 21a during boosting.

  After turning off the protection switch 21a, the control unit 19 intermittently outputs a signal for turning on the protection switch 21a. In each case, the current value detection means 81a acquires the current value. When the acquired current value is out of the predetermined range, the protection switch 21a is kept off. When the current value is included in the predetermined range, the protection switch 21a is turned off. Switch on.

The control unit 19 also turns off the protection switch 21a when the temperature input from the temperature measuring unit 82a exceeds a predetermined value. Since the control of the protection switch 21a based on the temperature measured by the temperature measuring means 82a is the same as the control based on the current value because overheating is caused by an overcurrent, the description thereof is omitted here.
The protection of the DC / DC converter 50b based on the current value and the temperature can be similarly realized.

  The determination as to whether or not the bypass switch 40b has failed is as follows. When the difference between the input voltage and the output voltage of the DC / DC converter 50b does not become 0 or very close to 0 after the control unit 19 outputs a signal for turning on the bypass switch 40b, the control unit 19 It is determined that the bypass switch 40b has failed.

  The current from the in-vehicle power source 9 flows through the protection switches 21e and 21f provided in the fuse box 2 without being boosted. The functions of the protection switches 21e and 21f are the same as those of the protection switches 21a, 21b, 21c, and 21d. That is, when the current value of the flowing current is outside the predetermined range, or when the detected temperature is equal to or higher than the predetermined temperature, the control unit 29 causes the protection switches 21e and 21f to cut off the current.

  FIG. 3 is a timing chart showing on / off operations of the bypass switches 40a and 40b and the protection switches 21a and 21b included in the vehicle power supply device 1. At the time t1 when the accessory signal (ACC signal) of B switches from off to on, the protection switch 21a of C and the bypass switch 40a of D are turned on. Subsequently, the F protection switch 21b and the G bypass switch 40b are turned on at a time t11 when the E ignition key signal (IG signal) is switched from OFF to ON. In this state, the vehicle is in a running state and the alternator 92 is generating power, so the DC / DC converters 50a and 50b are not boosted. A current from the in-vehicle power source 9 flows through the load 23a.

  At time t2 when the vehicle is stopped, idling stop is started, the alternator 92 is stopped, and the output voltage of the in-vehicle power supply 9 is decreased, the bypass switch 40a (D) is turned off, and the DC / DC converter 50a starts boosting. The boosted voltage is supplied to the load 23a through the protection switch 21a and the fuse 22a.

  Similarly, at time t2, the bypass switch 40b (G) is turned off, the DC / DC converter 50b starts boosting, and the boosted voltage is supplied to the load 23b through the protection switch 21b and the fuse 22b.

  Here, when the detected value of the current value detecting means 81a becomes temporarily abnormal at the time point ta1, the control unit 19 turns off the protection switch 21a (C), so that the DC / DC converter 50a and the load The protection of 23a is realized to be recoverable.

  At the time point t3 when the idling stop is completed, the engine (not shown) is started, and the output voltage of the in-vehicle power source 9 returns to the normal value due to the generator 92 generating power, the bypass switch 40a (D) is turned on and the DC / The DC converter 50a stops boosting. However, since the protection switch 21a (C) is off, the output voltage of the in-vehicle power supply 9 is not supplied to the load 23a.

  The control unit 19 continuously outputs a signal for turning on the protection switch 21a (C) at a predetermined interval, and whenever the current value detected by the current value detection means 81a is out of the predetermined range, each time the signal is output. The protection switch 21a continues to be turned off, and if it falls within the predetermined range, the protection switch 21a (C) is switched on.

  Similarly, at time t3, the bypass switch 40b (G) is turned on, the DC / DC converter 50b stops boosting, and the output voltage of the in-vehicle power supply 9 is applied to the load 23b through the protection switch 21b (F) and the fuse 22b. Supplied. After the time point t3, the protection switch 21a (C) is turned on at the time point ta2 when the current value detected by the current value detection means 81a is included in the predetermined range.

Even if the protection switch 21a is turned off and the current to the load 23a is cut off by the operation of the control unit 19 and the protection switch 21a, the current of the voltage boosted by the DC / DC converter 50a and the load 23c / Or current flows through the bypass switch 40a. In addition, a current passing through the DC / DC converter 40b and / or the bypass switch 40b flows to the load 23b and the load 23d.
Thereby, the boosted voltage or the voltage from the vehicle-mounted power supply 9 can be normally applied to other loads except the load 23a.

  Here, at time tb1, when the current value flowing through the protection switch 21a measured by the current value detection means 81a is out of the predetermined range, the protection switch 21a (C) is turned off. Thereby, the fuse 22a and the load 23a can be protected without fusing the fuse 22a. At the time tb2 when the detection value of the current value detection means 81a returns within the predetermined range, the protection switch 21a (C) is turned on again.

  At time tc1, when the current value flowing through the protection switch 21b (F) measured by the current value detection means 81b is out of the predetermined range, the protection switch 21b is turned off. Thereby, the fuse 22b and the load 23b can be protected without blowing the fuse 22b. At the time tc2 when the output voltage of the in-vehicle power supply 9 decreases to the normal value, the protection switch 21b (F) is turned on again.

  At time t4 when the ACC signal is switched from on to off, the protection switch 21a (C) and the bypass switch 40a (D) are turned off.

  At time t14 when the IG signal switches from on to off, the protection switch 21b (F) and the bypass switch 40b (G) are turned off.

  In the above example, the case where the detection value of the current value detection means 81a, 81b exceeds the normal value at the time point tb1 has been described, but the case where the measurement value of the temperature measurement means 82a, 82b is equal to or higher than the predetermined temperature is also described. Similarly to the above, the protection switches 21a and 21b are turned off, so that the protection of the DC / DC converter 50a can be ensured without using a fuse. The same applies to the operations related to the other protection switches 21c and 21d.

  As mentioned above, although the form for inventing was demonstrated, this invention is not limited to embodiment described in the form for implementing this invention. Modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Vehicle power supply device 10 Voltage conversion part 100 Case 19 Control part 2 Fuse box 21a, 21b, 21c, 21d, 21e, 21f Protection switch 22a, 22b, 22c, 22d, 22e, 22f Fuse 23a, 23b, 23c, 23d , 23e, 23f Load 29 Control unit 3 Fuse box 31a, 31b, 31e, 31f Fuse 40a, 40b Bypass switch 50a, 50b DC / DC converter 81a, 81b, 81c, 81d Current value detection means 82a, 82b, 82c, 82d Temperature Measuring means 9 On-vehicle power supply 91 Battery 92 Alternator

Claims (4)

One or a plurality of DC / DC converters that convert the output voltage of the power supply and supply it to the load, a fuse provided between the DC / DC converter and the load, and a series circuit of protection switches that protect the fuse In a power supply device comprising:
Detecting means for detecting a current value flowing through the protection switch;
A housing for housing the DC / DC converter, a protection switch, a fuse, and a detection means;
A power supply apparatus, wherein the protection switch is turned off when a current value detected by the detection means is out of a predetermined range. A measuring means for measuring the temperature of the DC / DC converter housed in the housing;
2. The power supply apparatus according to claim 1, wherein the protection switch is turned off when the temperature measured by the measuring means is higher than a predetermined temperature.   The said protection switch is a semiconductor relay which has the said detection means, Comprising: The processor which drives and controls the said semiconductor relay is provided based on the electric current value given from the said detection means, The Claim 1 or 2 characterized by the above-mentioned. Power supply.   3. The power supply device according to claim 2, wherein the protection switch is a semiconductor relay having the measurement unit, and includes a processor that drives and controls the semiconductor relay based on a temperature given from the measurement unit. .

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