JP2002162150A - Power source device for on-vehicle refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source device for an on-vehicle refrigerator capable of working by drawing a key of a vehicle at a luggage loading or unloading time or a loaded article conveying or delivering work time while maintaining a stable indoor temperature with a simple constitution in an idle-stop loading vehicle or a home delivery or distribution vehicle. SOLUTION: A sub-battery 2 connected to a main battery 1 via an isolator 5 is connected to a power source circuit 12b via an electromagnetic relay 13 having independent contacts of two circuits of a normally closed contact and a normally opened contact. The circuit 12b has a circuit for applying a voltage directly from the normally opened contact, and a circuit for passing a current from the normally closed contact for a prescribed time via a timer circuit 12c. The circuit 12b supplies a power to the circuit 12a of the on-vehicle refrigerator 8 for a prescribed time to drive a vibration type compressor 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for an on-vehicle refrigerator, and more particularly to a vehicle for home delivery and a vehicle for delivery.
The present invention relates to an improvement of a power supply device of a vehicle-mounted refrigerator mounted on a vehicle that temporarily stops an engine when the vehicle is stopped or when loading / unloading luggage.

[0002]

2. Description of the Related Art Recently, in the home delivery and delivery business, the demand for transporting refrigerated foods and frozen foods has increased, and home delivery and delivery vehicles equipped with refrigerators have been increasing. The compressor of this in-vehicle refrigerator is directly connected to the engine of the vehicle, directly connected to the engine, or in the case of an electric refrigerator,
A battery-driven refrigerator system in which a compressor is driven by electric power of a battery from an ACC terminal of a key switch of a vehicle, or disclosed in JP-A-9-46919 and JP-A-9-107.
A method of supplying power from a sub-battery using a charging controller disclosed in Japanese Patent No. 639 or the like is used.

In recent years, vehicles that adopt an idling stop that stops the engine at the time of unloading a red light or a load and restarts the engine at the time of starting are increasing in consideration of the global environment of the exhaust gas of the engine. This idling stop device is known in JP-A-59-39967 and the like.

[0004]

In a vehicle with an idling stop device, the compressor of the vehicle-mounted refrigerator is stopped every time the engine is stopped, which makes it difficult to maintain the temperature inside the refrigerator. When the electric refrigerator is mounted on the vehicle, if the key switch is unplugged while loading / unloading the luggage, the compressor of the on-board refrigerator will stop and it will be difficult to maintain the temperature inside the refrigerator, so it is necessary to always keep the key switch in the ACC position. However, in consideration of safety, it is in principle inconsistent to pull out the key of the vehicle and load / unload parcels or carry in / out the deliveries.

When an electric refrigerator that supplies power from a sub-battery using a charging controller is mounted on a vehicle, the compressor of the refrigerator is continuously driven until the voltage of the sub-battery reaches a lower limit specified value. Loading and unloading the cargo for a long time causes consumption of the sub-battery, and the user must wait until the battery returns to the compressor restart voltage, which is not suitable for courier service and delivery vehicles.

The present invention can maintain a stable internal temperature even in a vehicle equipped with an idling stop while adopting a simple configuration, and can be used for loading and unloading luggage in home delivery business.
It is an object of the present invention to provide a power supply device for a vehicle-mounted refrigerator that can be operated by removing a key of a vehicle during a loading / unloading operation of a load of a delivery vehicle.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a main battery for supplying power to a starter for rotating an engine when starting the engine, and a sub-battery for supplying power to a vehicle-mounted refrigerator. An alternator driven by the engine to charge the main battery and the sub-battery, a key switch having a starter start position and an accessory position that can be closed even when the engine is stopped, and a drive circuit unit that drives a compressor of the on-vehicle refrigerator. In a power supply unit for a vehicle-mounted refrigerator including a power supply circuit unit for selectively supplying a commercial AC power supply and a battery power supply to the drive circuit unit, an isolator is provided between a connection point between an alternator and a main battery and a sub-battery. To prevent the current from the sub-battery when starting the starter, Timer means provided at the input stage of the power supply circuit section, and an electromagnetic relay having two independent contacts of a normally closed contact and a normally open contact interlocked with energization of the exciting coil. One end is connected to the sub-battery and the other end is connected to the timer means, and one end of the normally open contact of the electromagnetic relay is connected to the sub-battery and the other end is directly connected to the power supply circuit section bypassing the timer means. I do. Further, the compressor is desirably a vibration type compressor.

According to the present invention, when the key switch is at least in the accessory position, the excitation coil of the electromagnetic relay is energized, the power is supplied from the sub-battery to the power supply circuit section, and the drive circuit section operates the compressor to operate the compressor. Cooling of the inside of the refrigerator becomes possible, and power can be continuously supplied from the sub-battery to the power supply circuit within a predetermined time after the key switch is turned off and the excitation coil is cut off. . Further, if the compressor is a vibration type compressor, it can be driven with a low current.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on one embodiment of the present invention shown in the attached drawings.

FIG. 1 is a block diagram showing the configuration of a power supply device for a vehicle-mounted refrigerator according to the present invention, and illustrates a case where the invention is applied to a home delivery vehicle equipped with an engine. This vehicle is equipped with a main battery 1, a sub-battery 2, an alternator 3, a starter 4, a key switch 5, an isolator 6, an idle stop device 7, and a vehicle-mounted refrigerator 8 in a driver's seat.

The main battery 1 is a lead storage battery having a small internal resistance, and its rated voltage is 12V. The main battery 1 is mainly provided as a power supply source of the starter 4 which requires a large current at the time of starting the engine, and also as a power supply of a vehicle load. The negative terminal of the main battery 1 is grounded, and the positive terminal is connected to the DC output terminal 3B of the alternator 3, the input terminal 5a of the starting key switch 5, the input terminal 6a of the isolator 6, and the fixed contact terminal (B) of the starter 4. You.

The sub-battery 2 is a normal lead-acid battery, and its rated voltage is 12V. The sub battery 2
Electric power is supplied to the on-vehicle refrigerator 8 mounted on the vehicle. The minus terminal of the sub-battery 2 is grounded, and the plus terminal is connected to the output terminal 6b of the isolator 6, the plus power supply terminal 7B of the idle stop device 7, and the electromagnetic relay 13 described later.

The alternator 3 is an alternator with an IC type regulator (three-phase alternating current generator). A rotor (not shown) is driven by an engine, and a three-phase stator winding 3u, which is excited by an excitation winding 3a, Three-phase alternating currents are induced in 3v and 3w, and are rectified by the rectifier circuit 3e to output a direct current for charging the main battery 1 and the sub-battery 2. The voltage induced in the star-connected three-phase stator windings 3u, 3v, 3w is obtained by detecting the output voltage value of the rectifier circuit 3e by the regulator 3f, comparing it with a preset threshold value, and rectifying one end. The transistor 3g in the regulator connected to the other end of the exciting winding 3a connected to the output of the circuit 3e is switched, and the freewheel diode 3h connected to both ends of the exciting winding 3a.
In conjunction with this, by controlling the exciting current of the exciting winding 3a, three-phase full-wave rectification is performed by the rectifier circuit 3e, and a voltage in an appropriate range is automatically adjusted and output to the DC output terminal 3B of the alternator 3. You.

The starter 4 is a normal automobile engine starter. The starter 4 applies a DC voltage only while the start key switch 5 in the driver's seat performs a start operation (to be described later in detail). Terminal (c), a pull coil (p) and a hold coil (h) connected to the terminal (c) and corresponding to the excitation coil of the electromagnetic switch, and a machine is energized by energizing the pull coil (p) and the hold coil (h). A movable contact 4b formed at one end of the rod 4a, an engagement switch 4c having two fixed contact terminals (B) and (M) bridged by the movable contact 4b, A pinion 4e, a pinion 4 protruding by a lever 4d interlocked with the other end of the pinion 4a;
e, a field winding 4f and an armature 4g, which constitute a DC motor for rotating e, are main components, and fixed contact terminals (B)
Is connected to the plus terminal of the main battery 1 and the fixed contact terminal (M) is connected to one end of the pull coil (p) and the armature 4.
g is connected to one end of the armature winding, the other end is connected to one end of the field winding 4f, and the other end is grounded.

The key switch 5 is provided in the vicinity of the driver's seat of the vehicle. Normally, a key for locking the door of the vehicle, starting the engine and turning on / off the electric system is inserted, and the key switch 5 is rotated by about 90 ° to allow the driver to turn the key. It has one stop position. The key switch 5 shown in FIG. 1 uses an input terminal 5a as a common terminal, an OFF position terminal 5b, and an accessory (A
CC) a position terminal 5c, an ON position terminal 5d, and a start position terminal 5e. The accessory (ACC) position terminal 5c is connected to the input terminal 5a at the ON position and the start position in addition to when the key switch 5 is at the accessory position. The ON position terminal 5d is connected to the input terminal 5a when the key switch 5 is in the ON position and the start position.

The isolator 6 has a function of separating the main battery 1 and the sub-battery 2. The input terminal 6a of the isolator 6 is connected to the positive terminal of the main battery 1, and the output terminal 6b. Is connected to the positive terminal of the sub-battery 2 and is connected to the ground terminal 6c.
Is grounded to the vehicle. The isolator 6 allows current to pass from the main battery 1 to the sub-battery 2 and blocks current from the sub-battery 2 to the main battery 1 so that a large current is supplied from the main battery 1 to the starter 4 when starting the engine. Therefore, even when the terminal voltage of the main battery 1 decreases, no current is supplied from the sub-battery 2, and the sub-battery 2 has a function of stabilizing the terminal voltage.

The idle stop device 7 stops the engine when the vehicle stops at a red light or unloads a load, and restarts the engine with a starter when the vehicle starts, in consideration of the global environment due to the exhaust gas of the engine. An output terminal 7A which is internally processed based on a signal from each sensor (not shown) from an input terminal 7I and outputs a control output for stopping the engine to an electronic governor (not shown) of the engine, etc .; Has a starter terminal 7C for outputting the voltage of the plus side power supply terminal 7B based on the control described above, and a ground terminal 7E. Therefore, the operation of the starter 4 is started by the engine start of the start key switch 5 or the output of the starter terminal 7C of the idle stop device 7.

An on-board refrigerator 8 has an evaporator 9 housed in a housing 8a surrounded by a heat insulating material, and a condenser 10, a vibrating compressor 11 as a compressor, and a power supply device 12 as main components outside the housing. The vibratory compressor 11 compresses the refrigerant, and forms a refrigeration cycle in combination with the evaporator 9 and the condenser 10, thereby cooling the inside of the storage body 8a.

The power supply device 12 includes a drive circuit section 12a, a power supply circuit section 12b, a timer circuit section 12c serving as timer means,
An electromagnetic relay 13 is provided. The drive circuit section 12a is a circuit dedicated to the vibration type compressor 11, and uses an inverter circuit that generates an optimum cycle and waveform. Power supply circuit section 12b
Has a role of selectively supplying a commercial AC power supply and a battery power supply to the drive circuit section 12a, and an AC power supply terminal for enabling connection from a commercial AC power supply such as AC100V for pre-cooling at a home delivery station or the like. The AC power from 12 d is switched between the internal AC-DC converter and the DC power from the sub-battery 2 via an electromagnetic relay 13 described later, and is further converted to a DC voltage optimal for the vibration compressor 11. Note that the switching has a function of automatically switching preferentially when a commercial AC power supply is connected.

The timer circuit 12c has an input terminal 12c.
i, an output terminal 12co, and a ground terminal 12ce,
A timer for measuring time is provided inside. The input terminal 12ci is connected to the output terminal 12co for a certain period of time from the time when the voltage changes from zero to the battery voltage.
It outputs the voltage applied to 2ci.

FIG. 2 shows the internal configuration of the timer circuit section 12c, which mainly includes a reset circuit 121, a delay circuit 122, a relay 123, and a constant voltage circuit 124. The reset circuit 121 determines whether the voltage applied to the input terminal 12ci has risen from zero to near the battery voltage,
It also has a function of latching whether the voltage has fallen to zero from around the battery voltage, and controls the start and stop of the operation of the delay circuit 122. The delay circuit 122 functions to keep the relay 123 turned on within a preset time after receiving the operation start signal from the reset circuit 121. The relay 123 turns on / off in response to a signal from the delay circuit 122, and connects / disconnects the voltage applied to the input terminal 12ci to / from the output terminal 12co.

Referring again to FIG. 1, the electromagnetic relay 13
Excitation coil 13a and two electrically independent first and second
Of the movable contact 13k and the movable contact 13x are commonly operated by energizing / de-energizing the exciting coil 13a. One end of the exciting coil 13a is connected to an accessory (ACC) position terminal 5c of the key switch 5, and the other end is grounded. The first movable / fixed contact set includes a movable contact 13k and two fixed contacts 13m and 13n.

The first set of movable / fixed contacts is a "normally open" contact, that is, the movable contact 13k opens between the two fixed contacts 13m and 13n when the exciting coil 13a is not excited, and only when the exciting coil 13a is energized. Fixed contact 13m, 1
It is a normal one bridging between 3n. The fixed contact 13m is connected to the positive terminal of the sub-battery 2 via a fuse F1, and the fixed contact 13n is connected to the power supply circuit unit 12b.

The second movable / fixed contact set includes two fixed contacts 13y and 13z having "normally closed" contacts, that is, the exciting coil 13
This is a so-called normally-on type in which the movable contact 13x short-circuits the two fixed contacts 13y and 13z when a is not excited. The fixed contact 13y has a fuse of F2.
And the fixed contact 13z is connected to the input terminal 12c of the timer circuit unit 12c.
i.

The operation of this embodiment constructed as described above will be described. When the engine is started, the driver operates the start key switch 5 to rotate it to the start position, and the input terminal 5a is turned to the start position terminal. 5e or the starter terminal 7 of the idle stop device 7
The starter 4 is operated by the output of C, and current is supplied to the starter 4 only from the main battery 1. At this time, even when the terminal voltage of the main battery 1 decreases, the sub-battery 2
Does not supply current. Therefore, there is no discharge at the time of starting from the sub-battery 2, and the terminal voltage is stable.

On the other hand, when the vehicle is running, that is, when the engine is rotating at a certain speed or more, the alternator 3 generates power and appropriately charges the battery according to the state of the main battery 1. At this time, the sub-battery 2 is charged via the isolator 6. At this time, the starting key switch 5 is in the ON position, and the voltage of the main battery 1 is set to O through the input terminal 5a.
N position terminal 5d and accessory (ACC) position terminal 5c
Has been applied.

When the starting key switch 5 is in the ON position, the voltage of the main battery 1 is also applied to the accessory (ACC) position terminal 5c.
Current flows through the exciting coil 13a, and the movable contact 13k bridges between the two fixed contacts 13m and 13n, so that power is supplied from the sub-battery 2 to the power supply circuit section 12b.
At the same time, the movable contact 13x, which short-circuits the fixed contacts 13y and 13z of the electromagnetic relay 13, separates, and the timer circuit 1
The input terminal 12ci of 2c falls from the voltage of the sub-battery 2 to zero.

When the power is supplied from the sub-battery 2 via the electromagnetic relay 13 to the power supply circuit section 12b, the power supply circuit section 12b selects the power supply to be effective and converts the voltage value. Apply proper voltage. The drive circuit unit 12a drives the vibrating compressor 11 to exhibit a function as a compressor, compresses the refrigerant, sends it to the evaporator 9, cools the inside of the storage body 8a, and then cools the condenser 10a.
Refrigeration cycle for returning to the vibratory compressor 11 to release heat to cool and cool the refrigerated items such as food stored in the in-vehicle refrigerator 8.

Since the idle stop device 7 is mounted, when information such as signal waiting is input from each sensor (not shown) to the input terminal 7I, an electronic governor (not shown) of the engine is output from the output terminal 7A. For example, the control output for stopping the engine is issued to stop the engine, and the idle stop adding unit 14 cuts off the current flowing through the exciting coil 13a of the electromagnetic relay 13. Also, after the vehicle is stopped for loading and unloading and the key switch 5 is turned to the OFF position, the current flowing through the exciting coil 13a of the electromagnetic relay 13 is also cut off when the key is removed.

When the current flowing through the exciting coil 13a of the electromagnetic relay 13 is cut off, the movable contact 13k opens the space between the two fixed contacts 13m and 13n, and the movable contact 13x
Bridges the two fixed contacts 13y and 13z, the voltage applied to the input terminal 12ci of the reset circuit 121 in the timer circuit section 12c rises from zero to near the battery voltage, and the delay circuit 122 operates and the relay 123 turns on and the input terminal 1 is connected to the output terminal 12co.
The voltage applied to 2ci is output.

Therefore, when the engine is stopped by the idle stop device 7, or when the key switch 5 is turned off.
Output terminal 1 for a predetermined time after the key is removed
Since the power supply from the sub-battery 2 is continued from the 2co to the power supply circuit unit 12b from the sub-battery 2, the driving of the vibrating compressor 11 is continued and the temperature of the inside 8a of the refrigerator 8 is maintained to maintain the function as a compressor. Is done.

When a predetermined time has elapsed by the delay circuit 122 of the timer circuit section 12c, the power supply to the power supply circuit section 12b is stopped because the relay 123 is turned off.
The vibration type compressor 11 stops along with the drive circuit section 12a.
Therefore, when the engine is stopped or the key switch 5 is turned off and the key is removed for a long time, the vehicle-mounted refrigerator 8 is automatically stopped after a predetermined time has elapsed, and the sub-battery 2 (including the main battery 1) is stopped. Overdischarge can be prevented.

FIG. 3 shows a timer circuit 1 serving as timer means.
FIG. 4 shows an internal configuration block diagram according to another embodiment of 2c, in which an interface 125, a CPU 126, a driver 127, a transistor 128, and a constant voltage circuit 129 are main components, and FIG. . The interface 125 is a comparison circuit having a threshold value for determining whether the voltage applied to the input terminal 12ci is zero or near the battery voltage. The CPU 126 is a processor constituted by a microcomputer or the like and forms a central part of control. is there. The driver 127 receives the output of the CPU 126 and drives the transistor 128. The constant voltage circuit 12
Numeral 9 supplies a stabilized voltage to each section.

FIG. 4 is a flowchart relating to the control of the CPU 126 in FIG. 3, and the operation will be described based on the flowchart. When the battery voltage is applied to the input terminal 12ci of the timer circuit unit 12c, the "input voltage" is at the "H" level, and when the "flag" is checked on the software, the driver 127 is turned off. And reset the "timer" on the software. This situation corresponds to the initial state.

When the driver switches from the key insertion to the accessory position, the electromagnetic relay 13 is activated, so that the input terminal 12ci transitions from the battery voltage to zero. At this time, since the “input voltage” is at the “L” level, the “flag” and “set” are set on software, and the driver 12
7 as well as "reset" the software "timer". This state is also applied during startup of the engine and during normal running.

When the engine is stopped from the idle stop device 7 or the key is removed after the key switch 5 is turned off, the exciting coil 1 of the electromagnetic relay 13 is turned off.
Since the current flowing through 3a is cut off, the movable contact 13k opens between the two fixed contacts 13m and 13n, and the movable contact 13x bridges the two fixed contacts 13y and 13z. At the terminal 12ci, a signal whose voltage has risen from zero to near the battery voltage is input to the CPU 126 via the interface 125.

Since the "input voltage" recognizes the "H" level, when looking at the "flag" on the software, the CPU 126 turns on the driver 127 because the "flag set" has been in effect since the last time. At the same time, a "timer" on the software is set, and the timer is counted up. The transistor 127 is driven by the driver 127 until the "timer" is up, that is, a predetermined time has elapsed, and the transistor 128 is applied to the output terminal 12co and the input terminal 12ci.

Therefore, when the engine is stopped by the idle stop device 7, or when the key switch 5 is turned off.
Output terminal 1 for a predetermined time after the key is removed
Since the power supply from the sub-battery 2 is continued from the 2co to the power supply circuit unit 12b from the sub-battery 2, the driving of the vibrating compressor 11 is continued and the temperature of the inside 8a of the refrigerator 8 is maintained to maintain the function as a compressor. Is done.

When a predetermined time has elapsed and the "timer" counts up, the CPU 126 turns off the driver 127 and resets the "timer" on the software to reset. Therefore, the transistor 128 is shut off, no voltage appears at the output terminal 12co, the power supply to the power supply circuit unit 12b is stopped, and the vibration type compressor 11 is stopped together with the drive circuit unit 12a. In this alternative embodiment, the engine is stopped or the key switch 5 is turned off for a long time.
When the F position and the key are removed, the in-vehicle refrigerator 8 is automatically stopped after a predetermined time has elapsed and the sub-battery 2
Overdischarge of the main battery 1 (including the main battery 1) can be prevented.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible. For example, in the case of a vehicle not equipped with the idle stop device 7, the idle stop addition unit 14 is not attached, and
b It is possible to make a connection in which both terminals are short-circuited with an option code.

[0041]

According to the present invention, a main battery for supplying electric power to a starter for rotating and driving the engine when the engine is started, a sub-battery for supplying electric power to a vehicle-mounted refrigerator, and a main battery driven by the engine and charging the sub-battery are provided. An alternator, a starter start position, and a key switch having an accessory position that can be closed even when the engine is stopped, a drive circuit unit for driving the compressor of the vehicle refrigerator, and a commercial AC power supply and a battery power supply for the drive circuit unit. And a power supply circuit unit for selectively supplying power to the vehicle-mounted refrigerator, wherein an isolator is provided between a connection point between the alternator and the main battery and the sub-battery, and the start-up of the starter starts from the sub-battery. A timer that blocks current and is provided at the input stage of the power supply circuit And an electromagnetic relay having two independent contacts, a normally closed contact and a normally open contact, interlocked with energization of the exciting coil, one end of the normally closed contact of the electromagnetic relay being connected to the sub-battery and the other end being timer means. And one end of the normally open contact of the electromagnetic relay is provided with a technical means connected to the sub-battery and the other end is connected directly to the power supply circuit unit by bypassing the timer means, so while taking a simple configuration, Power supply unit for vehicle-mounted refrigerators that can maintain a stable internal temperature even in vehicles equipped with an idling stop function and in vehicles where the key is removed when loading or unloading luggage in delivery service or when loading and unloading cargo in delivery vehicles Can be provided. Further, in a long-time stop work, an over-discharge of the battery can be prevented by an automatic power-off function.

Furthermore, if the compressor is a vibration-type compressor, it can be driven at a low current, and it is possible to provide a power supply unit for a vehicle-mounted refrigerator that achieves energy saving and is robust against vehicle vibration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a power supply device for a vehicle-mounted refrigerator according to the present invention.

FIG. 2 is a block diagram showing an internal configuration of a timer circuit unit according to the embodiment of the present invention.

FIG. 3 is a block diagram showing the internal configuration of a timer circuit unit according to another embodiment of the present invention.

FIG. 4 is a flowchart of a CPU inside a timer unit according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main battery 2 ... Sub-battery 3 ... Alternator 4 ... Starter 5 ... Key switch 6 ... Isolator 8 ... In-vehicle refrigerator 11 ... Compressor (vibration type compressor) 12a: drive circuit section 12b: power supply circuit section 12c: timer means (timer circuit section) 13: electromagnetic relay

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/00 302 H02J 7/00 302C 7/14 7/14 H

Claims (2)

[Claims] 1. A main battery that supplies electric power to a starter that rotationally drives the engine when the engine is started, a sub-battery that supplies electric power to a vehicle-mounted refrigerator, and charges the main battery and the sub-battery driven by the engine. An alternator, a key switch having a position for starting the starter and an accessory position for closing the engine even when the engine is stopped, a drive circuit unit for driving the compressor of the on-vehicle refrigerator, and a commercial AC power supply for the drive circuit unit. And a power supply circuit unit for selectively supplying a battery power supply.
A connection point between the alternator and the main battery,
In addition to providing an isolator between the sub-battery and preventing current from the sub-battery when the starter is started, a timer means provided at an input stage of the power supply circuit unit is interlocked with energization of an exciting coil. An electromagnetic relay having two independent contacts of a normally closed contact and a normally open contact, wherein one end of the normally closed contact of the electromagnetic relay is connected to the sub-battery and the other end is connected to the timer means, One end of the normally open contact is connected to the sub-battery, and the other end is directly connected to the power supply circuit unit, bypassing the timer means. When the key switch is at least in the accessory position, the excitation coil of the electromagnetic relay is energized. At the same time, the key switch is turned off and the power supply to the power supply circuit unit is performed for a predetermined time after the energization of the excitation coil is cut off. Automotive refrigerator power supply with power from the sub-battery to be characterized in that it is supplied. 2. The power supply device for an in-vehicle refrigerator according to claim 1, wherein the compressor of the refrigerator is a vibration compressor.