JPS62103493A - Power source switch device for car-loaded refrigerator - Google Patents

Abstract

PURPOSE:To easily switch a source voltage via a control signal line by providing a stopping circuit in parallel to the drive circuit of a switching element provided on a driving power source generating part. CONSTITUTION:A stopping circuit 51 consists of an evaporator temperature comparator 10, an OR circuit 20, and a power source switch 52. And, a logic H signal which is outputted by this stopping circuit 51 to circuits 1-3, stops outputs Q, Q are stopped, the supply of direct current to switching transistors TR1, TR2 is stopped, cutting off a power source to a compressor.

Description

[Detailed description of the invention] (Industrial application field) The present invention is a power switch device for a vehicle-mounted refrigerator.

In particular, in a compressor drive control device that controls the drive of a vibrating compressor using a predetermined frequency corresponding to the load, the on/off switch of the drive power supply to the compressor is performed via the control signal line. This invention relates to a power switch device for a vehicle-mounted refrigerator.

(Prior Art) There is a refrigerator that compresses and liquefies a gaseous refrigerant using a vibrating compressor and performs cooling etc. using the heat of vaporization when the liquefied refrigerant evaporates. Conventional.

As an example of a vibrating compressor drive control system used in the refrigerator, there is a system as shown in FIG. In FIG. 4, the vibrating compressor 5 includes switching transistors TR,...
By alternately switching TR into a conductive state, DC power V is alternately applied to the primary windings of the transformer 4 having different polarities, and the drive is controlled so that a resonance state, that is, maximum efficiency is obtained. At this time, the switching transistor T
R.

TR is alternately switched between a conducting state and a non-conducting state in a manner such as the current waveform shown in FIG. 5, and the switching frequency is controlled to match the resonant frequency of the vibrating compressor 5. To be more specific, the drive circuit 1-3 is changed so that the collector current "Ic" in FIG.
A base current "1." is alternately supplied to the bases of the switching transistors TR, , TR. That is,
By supplying a so-called trapezoidal waveform as shown in the figure from ■ to ■ as a current waveform in which the base current "I," is multiplied by the current amplification factor "hFE", at positions such as points P1 to P3 in the figure, ■, ≧h, respectively. , , xlB, the switching transistors TR, , TR2 are alternately switched between a conductive state and a non-conductive state to obtain a driving power source of a desired frequency. Conventionally, as explained above, the compression [5] has been driven using a driving power source that matches the resonance frequency of the vibration type compression a5.

In conventional in-vehicle refrigerators that drive the compressor 5 using a drive power source that matches the resonant frequency of the vibrating compressor A5, the power switch that supplies or cuts off power is connected directly to the power line. I was going there.

(Problem to be solved by the invention) Therefore, the power switch needs to be installed in a position that is easy to operate from the outside, and the power line wires are routed around inside the device, resulting in unnecessary voltage drop and power loss. It was causing a lot of wear and tear. Also.

Since the power line is turned on and off, the contacts of the power switch are subject to severe wear, requiring the use of a switch with a large capacity, and since an AC switch is used, one with high withstand voltage must be used. Ta.

The present invention aims to solve the problems mentioned in 2.

Instead of turning the power line on and off, the power generation section that generates the power supply for the compressor is stopped using the on/off signal from the control signal line.

It is an object of the present invention to provide a power switch device for a vehicle-mounted refrigerator in which a power supply voltage is easily switched via a control signal line.

(Means for Solving the Problems) Therefore, the power switch device for an on-vehicle refrigerator of the present invention is a compressor drive control device that controls the drive of a vibrating compressor using a predetermined frequency corresponding to the load. comprising a drive power generation section that generates drive power at a predetermined frequency;
A compressor drive control device that drives the compressor using the drive power generated by the drive power generation section, the drive circuit controlling driving of a switching element provided in the drive power generation section at a predetermined frequency. For that output Q
, Q is provided, and the drive power source of the drive power generation section is turned on and off by an on/off signal from the stop circuit.

(Example) This will be explained below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of a power switch device for a vehicle refrigerator according to the present invention, FIG. 2 is a schematic configuration diagram of a vehicle refrigerator to which the present invention is applied, and FIG. 3 is a vehicle refrigerator to which the present invention is applied. 1 shows a circuit configuration of an embodiment of a commercial refrigerator.

Before explaining the power switch device for an on-vehicle refrigerator according to the present invention, the outline of the on-vehicle refrigerator to which the present invention is applied and the circuit configuration in which the present invention is used will be explained.

In FIG. 2, 1 is a control circuit, 1-1 is a temperature detection section,
1-2 is an arithmetic unit, and 1-3 is a drive circuit.

2.3 is a temperature detector, 4 is a transformer, and 5 is a compressor.

6 represents a condenser, 7 represents a pressure reducer, 8 represents a refrigerator, and 8-1 represents an evaporator.

In the figure, the control circuit 1 includes a temperature detection section 1-1. Composed of a calculation unit 1-2 and a drive circuit 1-3, the refrigerant is compressed and discharged by the compressor 5 and a temperature detector (T,) 2 that detects the temperature corresponding to the saturated vapor pressure of the refrigerant taken in by the compressor [5]. Based on the respective signals from the temperature detector (T(i) 3) which detects the temperature corresponding to the saturated vapor pressure of the refrigerant, the compressor 5 is supplied with a drive signal having a frequency such that the compressor 5 is driven in a resonant state. It should be noted that the temperature detected by the temperature detection unit 1-1 is considered to be a temperature that substantially corresponds to the pressure of the refrigerant on the suction side and the pressure of the refrigerant on the discharge side. It's fine.

The vibrating compressor 5, supplied with drive power generated by the drive signal supplied from the control circuit 1, compresses the refrigerant and supplies a mixture of gas and liquid to the condenser 6. It emits heat and liquefies it. Then, the liquefied refrigerant is vaporized in an evaporator 8-1 provided in the refrigerator 8 via the pressure reducer 7, and cools the refrigerator 8 by removing the heat of vaporization. The refrigerant that has absorbed the heat of vaporization is compressed again by the compressor 5. By repeating the clost cycle as described above, the evaporator 8-
The heat taken away from the condenser 6 will be released in the form of heat from the condenser 6. The operation of the control circuit 1 will be described in detail below.

In the figure, a temperature detection section 1-1 is for converting a signal detected by a temperature detector (for example, a thermistor) 2.3 into a predetermined electric signal.

In the figure, the calculation unit 1-2 calculates the temperature corresponding to the suction pressure, which is converted into an electrical signal by the temperature detection unit 1-1, and [
This is to generate a voltage corresponding to the frequency at which the compressor 5 is driven in a resonant state based on the temperature corresponding to the discharge pressure. and.

The drive circuit 1-3 sends a drive signal of a frequency corresponding to the voltage supplied from the calculation unit 1-2 to the transistor T in the figure.
2. DC power supply shown in Figure 2 ■ supplies to RI and TR2. , to the primary winding of the transformer 4 in the form of a so-called rectangular wave in which the polarity is alternately switched to the windings having different polarities. The AC voltage obtained from the secondary winding of the transformer 4 is supplied to the compressor 5.
is always driven in a resonant state, that is, driven at maximum efficiency.

In the circuit configuration of an embodiment of a vehicle refrigerator in which the present invention is used in FIG. 3, the symbols 11.12.1-3.2 to 5, TR+, and T Rz are the same as those in FIG. 2. Therefore, its explanation will be omitted.

9 is a thermo device, 10 is an evaporator temperature comparator,
11 is a transformer, 12 is an AC detector, 13 is a surge absorption circuit, 14 is an overcurrent detection circuit, 15.16 is a relay, 1
7.18 is an AND circuit, 19.20 is an OR circuit, 21 is an inverter, 22 and 23 are diodes, 24 is a volume, and 25 is a shunt.

The thermo device 9 is for setting the indoor temperature of the refrigerator, and the volume 2 provided in the thermo device 9 is
The indoor temperature of the refrigerator changes depending on the setting in step 4.

The evaporator temperature comparator 10 uses the signal of the indoor temperature of the refrigerator set by the volume 24 and the evaporator 8-
It electrically compares the signal from temperature detector 2 which is detecting the temperature of 1 and outputs a logic "L" when the set temperature of the 9 thermostats becomes higher than the temperature of the evaporator 8-1 side. do. The output of the logic rLJ becomes a stop signal to the drive circuit 1-3 via an OR circuit 20 having a negative input terminal, and also becomes a stop signal to the drive circuit 1-3 via an AND circuit 17 to the relay 16.
The contact of the transformer 4 is turned off through the relay 16.
．． That is, the supply of DC power to the transistors TR, TR2 is cut off.

The transformer 11 is for detecting when the in-vehicle refrigerator is connected to a commercial power source, and drops the voltage of the commercial power source. Supply voltage.

The alternating current detector 12 detects whether or not commercial power is supplied manually, and when commercial power is input.

Outputs logic rHJ. The logic “11” is the OR circuit 20
The stop signal is sent to the drive circuit 1-3 via the AND circuit 17, and the contact of the relay 16 is turned off. That is, transistor TR,.

Cut off the DC power supply to TR2. Further, the contact of the relay 15 is turned on via the AND circuit 18, and AC power is supplied to the transformer 4 via the relay 15.

The surge absorption circuit 13 absorbs the surge voltage of the input DC power supply and supplies the DC power to the drive circuit 1-3, and also outputs the logic rHJ when the voltage of the input DC power supply is higher than a predetermined voltage. Output. The logic "H" is applied to the drive circuit 1-3 via the OR circuit 19 to the transistor TR.

The output of the TRZ is controlled, and the stroke of the compressor 5 is controlled.

The overcurrent detection circuit 14 detects an overcurrent flowing through the transistors TR, . , and outputs an output off latch signal that stops the operation of transistors TR,.

Prevent damage to TR, etc.

Next, the present invention will be explained in more detail using FIG.

In FIG. 1, symbols] -2, I-3, 4, 5°TR,
, TRI corresponds to the one in FIG. 2 already explained, and is designated by the symbol 1.
0.16, 17, 2.0.21.25 correspond to those in FIG. Reference numeral 31 represents a drive power generation section, 51 represents a stop circuit, and 52 represents a power switch.

The stop circuit 51 is composed of an evaporator temperature comparator 10° OR circuit 20 and a power switch 52, and the logic rH output from the stop circuit 51 to the drive circuit 1-3.
J causes the outputs Q and Q from the drive circuit 1-3 to be stopped, which are alternately output at the resonant frequency.

The evaporator temperature comparator 10 is as described above.

The indoor temperature of the refrigerator set on the thermometer 9 side and T
, the signal from the evaporator 8-1 side is electrically compared with the temperature from the evaporator 8-1 side, and when the temperature on the evaporator 8-1 side becomes lower than the indoor temperature setting of the refrigerator set on the thermometer 9 side, the A logic "11" is output via an OR circuit provided in the evaporator temperature comparator 10 to be described. The logic rH from the evaporator temperature comparator 10
J is.

A stop signal is sent to the drive circuit 1-3 via the OR circuit 20, and at the same time, the relay is deenergized via the AND circuit 17, and the switching transistors TRI, TR2
The configuration is such that the supply of DC voltage to the terminal is stopped.

When the power switch 52 is set to the power-on side.

For example, the power switch 52 is turned on and connected to ground. The logic "L" connected to this ground is input to the OR circuit provided in the evaporator temperature comparator 10, but does not cause any change to the OR circuit. In addition, when the power is turned off, the power switch 52
turns off, and the logic rT(J is input to the OR circuit provided in the evaporator temperature comparator 10. As a result, the logic rHJ is output from the OR circuit. In other words, the logic rHJ is output from the evaporator temperature comparator 10. As explained above, the logic rHJ serves as a stop signal to the drive circuit 1-3, and also functions to stop the supply of DC voltage to the switching transistors TR, TR2.In other words, it controls to turn on and off the power supply switch 52. Power supply/cutoff control to the compressor 5 can be performed based on system signals.

(Effects of the Invention) As explained above, according to the present invention, since the power is supplied and cut off by signals from the control system, the electric wires used are thin (and have low withstand voltage). This simplifies the routing of electric wires within the

Furthermore, since the signal is based on the '411 system, a power switch with a small contact capacity can be used, and the power switch can be placed outside the device at a location where it can be easily operated. Then replace the power switch.

It is also possible to replace signals from pressure switches, engine keys, etc.

[Brief explanation of drawings]

FIG. 1 shows the configuration of an embodiment of a power switch device for an on-vehicle refrigerator according to the present invention, FIG. 2 is a schematic configuration diagram of an on-vehicle refrigerator to which the present invention is applied, and FIG. An example configuration of a commercial refrigerator. FIG. 4 is an explanatory diagram illustrating a conventional compressor drive control system;
FIG. 5 shows an operation explanatory diagram for explaining the operation of the compressor drive control system shown in FIG. 4. In the figure, 1 is a control circuit, 1-1 is a temperature detection section, ■-2 is a calculation section, 1-3 is a drive circuit, 2 and 3 are temperature detectors, and 4
is a transformer, 5 is a compressor, 6 is a condenser, 7 is a pressure reducer, 8 is a refrigerator, 8-1 is an evaporator, 10 is an evaporator temperature comparator, 16 is a relay, 17 is an AND circuit, 19 is an OR circuit, 21 represents an inverter, 51 represents a stop circuit, and 52 represents a power switch.

Claims (1)

[Claims] A compressor drive control device that controls the drive of a vibrating compressor using a predetermined frequency corresponding to a load, comprising a drive power generation section that generates a drive power supply of a predetermined frequency, and a drive power generation section that generates a drive power supply of a predetermined frequency. A compressor drive control device that drives the compressor using a drive power source, which outputs Q, @Q to a drive circuit that drives and controls a switching element provided in the drive power generation section at a predetermined frequency.
A power switch device for a vehicle-mounted refrigerator, characterized in that a stop circuit for stopping @ is provided, and the drive power source of the drive power generation section is turned on and off by an on/off signal from the stop circuit.