JPS634033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device, particularly for generating an alternating voltage.
In a cooling system equipped with an AC voltage generation circuit and a vibratory compressor that is driven by being supplied with an alternating voltage from the AC voltage generation circuit, the alternating voltage supplied to the vibratory compressor is adjusted to the ambient temperature of the cooling system. and/
The present invention also relates to a cooling device that performs phase control based on the evaporator temperature and/or the potential of the DC power source to prevent failures such as valve chamber destruction due to an undesired compression level.

A cooling device generally includes an AC voltage generation circuit that generates an alternating voltage, such as an inverter circuit or an oscillator circuit, a vibratory compressor that is driven by being supplied with the alternating voltage from the AC voltage generation circuit, and a compressor that is compressed by the compressor. It is equipped with a condenser to which the output refrigerant is guided, a capillary tube provided downstream of the condenser, and an evaporator provided downstream of the capillary tube, and the refrigerant vaporized by the evaporator is subjected to the above-mentioned vibration type compression. It is made to be compressed again by the machine.
However, this type of cooling system is difficult to operate when operated at very low ambient temperatures or when generating alternating voltages.
If the DC power supply that supplies the AC voltage generation circuit is operated under high potential, the piston stroke of the vibratory compressor will increase undesirably, resulting in damage to the valve chamber. . for example,
The above-mentioned cooling device is often used in refrigerators installed in leisure vehicles (camping cars), but when such a leisure vehicle is stopped at a ski resort, for example, the outside temperature may drop. The above phenomenon occurred. That is, since the temperature inside the vehicle is air-conditioned, the refrigerator installed in the leisure vehicle is operated. However, on the other hand, the condenser connected to the vibrating compressor of a refrigerator is exposed to the outside temperature, and in extreme cases is cooled by the outside air temperature of about -30°C. For this reason, most of the refrigerant is stored in the condenser in a liquefied state, and the refrigerant that flows out little by little into the evaporator and is adiabatically expanded is immediately sent to the condenser by the vibrating compressor, so to speak. The gas pressure inside the vibrating compressor becomes vacuum. As a result, the piston stroke of the vibratory compressor increases undesirably, destroying the valve chamber.

Needless to say, the vibratory compressor minimizes the natural vibration frequency of the mechanical system given by the elastic coefficient of the refrigerant gas, the spring coefficient of the resonance spring, etc., and the vibration frequency of the electrical system that drives the mechanical system as much as possible. It is kept in a resonant state. In particular, as mentioned later,
In the case of a cooling system that is configured to maintain a correct resonant state by changing the vibration frequency of the electrical system in accordance with fluctuations in the natural vibration frequency of the mechanical system, as described above, the gas pressure of the refrigerant decreases and the vibration frequency of the mechanical system changes. Even if the vibration frequency changes, the electrical system follows it and changes the vibration frequency of the alternating voltage to maintain a resonant state, so it is directly sensitive to the effects of the increase in piston stroke. Become.

Furthermore, if a battery is used as the DC power supply to the AC voltage generation circuit that generates the alternating voltage, the battery becomes over-discharged due to the drive of the vibrating compressor, making it impossible to start the engine of the leisure vehicle. has.

The present invention aims to solve the above-mentioned difficulties and provides an alternating voltage supplied to the vibratory compressor in response to a decrease in the ambient temperature of the cooling device and/or the temperature of the evaporator and/or to the potential of the DC power supply. The piston of the vibrating compressor
By reducing the stroke, if the cooling device is exposed to very low ambient temperature conditions,
This prevents the piston stroke of the vibratory compressor from increasing and damaging the valve chamber when the potential of the DC power supply is high, and also reduces the ambient temperature and/or
or when the temperature of the evaporator drops below a predetermined temperature and/or when the potential of the DC power supply that supplies the AC voltage generation circuit that generates the alternating voltage is above the predetermined potential or below the predetermined potential The purpose of the present invention is to provide a cooling device that stops the alternating voltage supplied to the vibratory compressor when the voltage drops to 0.1, and also provides hysteresis for stopping and starting the vibratory compressor based on the above-mentioned causes. The cooling device of the present invention will be explained below based on the drawings.

Fig. 1 is an explanatory diagram conceptually showing an embodiment of the cooling device of the present invention, Fig. 2 and Fig. 3 A, B, and C.
is an explanatory diagram for explaining the operation of the cooling device shown in FIG. 1, FIG. 4 is an example configuration of the phase control circuit shown in FIG. 1, and FIG. 5 is a specific example of the phase control circuit and AC voltage generation circuit. Example circuit configuration, FIGS. 6 to 8 show an example circuit configuration of a cut-off circuit and a display circuit, and FIG. 9 shows voltage and current waveform diagrams in each circuit with and without phase control, respectively. ing.

In FIG. 1, 100 is a vibrating compressor, 20
0 is a capacitor, 300 is a strainer that constitutes a filter, 400 is a capillary tube, 500 is an evaporator, 600 is an AC voltage generation circuit such as an inverter circuit or an oscillator circuit, and 700 is a main unit. The phase control circuit 800 produced by the invention is a DC power supply, for example, a battery installed in a car.
900 represents an electrical conductor.

For example, in a leisure vehicle, at a stop where a commercial power source is available, the commercial power source is rectified to charge the battery 800 while operating the electrical equipment in the vehicle, and the vibrating compressor 100 is connected via the inverter circuit 600. The above battery 800 is used at stops where commercial power is not available.
The in-vehicle electrical equipment is driven, and the vibrating compressor 100 and the like are driven via the inverter circuit 600. Furthermore, while the vehicle is running, the battery 800 is floatingly charged by a generator mounted on the vehicle. When driving the vibratory compressor 100, an alternating voltage is generated by a DC/AC converter, that is, an AC voltage generation circuit 600, such as an inverter circuit or an oscillator circuit, to drive the vibratory compressor 100. be done.

The vibratory compressor 100 compresses the refrigerant gas and supplies it to the condenser 200. In the condenser 200, the refrigerant gas is cooled by outside air and partially liquefied, and the refrigerant is passed through the strainer 300 and the capillary tube 400. It is adiabatically expanded in the evaporator 500. Then, it is compressed again by the vibratory compressor 100.

In the case of the present invention, a phase control circuit 700 is provided, and the phase control circuit 700 includes an inverter circuit 6.
For example, when the alternating voltage output from the inverter circuit 600 is approximately a rectangular wave, the alternating voltage generated from the inverter circuit 600 and supplied to the vibratory compressor 100 is phase-controlled. The conduction time width T of each half-wave of the waveform voltage is increased or decreased so as to be supplied to the vibratory compressor 100. That is,
A variable no-voltage period corresponding to the illustrated time width T' is provided, and the vibratory compressor 1 is controlled by controlling the variable time width T'.
Controls energy supply to 00.

3A, B, and C show the characteristics of the alternating voltage supplied to the vibratory compressor 100 according to the present invention. In the case of the present invention, the phase control of the alternating voltage as described above is performed based on (1) the ambient temperature to obtain the alternating voltage-ambient temperature characteristic as shown in FIG. 3A;
(2) Based on the evaporator temperature, Figure 3B
(3) To obtain the evaporator temperature characteristics, the alternating voltage as shown in FIG.
Try to obtain battery voltage characteristics. That is, (1) When the phase control of the alternating voltage is performed based on the ambient temperature, as shown in FIG. 3A, the alternating voltage level is lowered as the ambient temperature falls, and the It has hysteresis that maintains the alternating voltage at zero level while the temperature is below T _A and maintains the alternating voltage at zero level until the ambient temperature rises and reaches a predetermined temperature value T _B (T _B > T _A ). (2) When the phase control of the alternating voltage is performed based on the evaporator temperature, the alternating voltage level is lowered as the evaporator temperature falls, as shown in FIG. It has hysteresis that maintains the alternating voltage at zero level while it is below the value T _C and maintains the alternating voltage at zero level until the evaporator temperature rises and reaches a predetermined temperature value T _D (T _D > T _C ). , (3) When the phase control of the alternating voltage is performed based on the battery voltage, as shown in FIG. 3C,
A case in which phase control is not performed on the rate of increase in the alternating voltage level with respect to the increase in battery voltage while the battery voltage is above a predetermined first voltage value V ₀ and below a predetermined second voltage value V ₁ On the other hand, while the battery voltage is below the first voltage value V ₀ and while it is above the second voltage value V ₁ , the alternating voltage is maintained at zero level, and the battery voltage is When the voltage rises from below the first voltage value V ₀ , the alternating voltage maintains the zero level until it reaches the third voltage value V ₂ (V ₀ <V ₂ ), and the battery voltage increases below the second voltage value. The alternating voltages each have a hysteresis that maintains the zero level when falling from the value V ₁ or higher until reaching the fourth voltage value V ₃ (V ₃ <V ₁ ).

FIG. 4 shows the configuration of an embodiment of the phase control circuit shown in FIG.
700 and 800 correspond to those in FIG. 1 is a reference voltage circuit, which is a DC power supply, that is, a battery 80
2 is a switching circuit that generates a reference voltage from 0 and supplies the reference voltage to a pulse width determining circuit 4, a low temperature cut-off circuit 6, a low voltage cut-off circuit 8, and a high voltage cut-off circuit 10, which will be explained later. The switching control circuit 3 is a detection circuit that detects the rising edge of the switching of the alternating voltage generated by the inverter circuit or oscillator circuit of the AC voltage generation circuit 600 and sends a trigger pulse signal to the switching control circuit 3 described below. The main switching element of the inverter circuit or oscillator circuit of the AC voltage generation circuit 600, for example, the base potential of the main transistor, is manipulated to turn the main transistor on and off to adjust the power supplied to the vibratory compressor 100. thing. That is, when a trigger pulse signal is sent from the switching detection circuit 2 to the switching control circuit 3, the base potential of the main transistor is pulled to ground potential, the alternating voltage supplied to the vibratory compressor 100 is stopped, and at the same time, the pulse Sends a signal to the width determining circuit 4, waits for a signal from the pulse width determining circuit 4, and then outputs the signal to the pulse width determining circuit 4.
When the pulse width determining circuit 4 receives a signal from the switching control circuit 3, it stops drawing in the base potential of the main transistor and supplies an alternating voltage to the vibrating compressor 100. The temperature detection circuit 5, which determines the pulse width according to the voltage and the ambient temperature or evaporator temperature of the temperature detection circuit 5 to be explained next, and sends a signal to the switching control circuit 3, is made of a temperature-dependent resistor. The low-temperature cut-off circuit 6 sends detection information to the pulse width determining circuit 4 and the low-temperature cut-off circuit 6, and the low-temperature cut-off circuit 6 uses information from the temperature detection circuit 5 to determine whether the temperature of the temperature detection circuit 5 is below a preset value. When this happens, a signal is sent to the pulse width determining circuit 4, and while the signal is being sent, the alternating voltage supplied to the vibrating compressor 100 is stopped.The low temperature cut-off circuit 6 is used to prevent chattering. As explained in FIGS. 3A and 3B, 7 is a low-temperature cut-off display circuit which has hysteresis characteristics, and when the temperature detected by the temperature detection circuit 5 falls below a preset value, the vibration-type compression The low voltage cut-off circuit 8, which indicates that the machine 100 is stopped, sends a signal to the pulse width determining circuit 4 when the voltage of the battery 800 falls below a preset value, and the signal is sent out. 9 is a low-voltage cut-off voltage that stops the alternating voltage supplied to the vibrating compressor 100 while the vibration is in progress, and has a hysteresis characteristic as shown in FIG. 3C to prevent chattering.
The off display circuit indicates that the voltage of the battery 800 is below a preset value and the vibratory compressor 10
0 is stopped, the high voltage cut-off circuit 10 turns off the pulse width determining circuit 4 when the voltage of the battery 800 exceeds a preset value.
It sends a signal to the oscillating compressor 100, and stops the alternating voltage supplied to the vibratory compressor 100 while the signal is being sent, and is shown in Fig. 3C to prevent chattering.
Those with hysteresis characteristics as shown in the figure,
Reference numeral 11 denotes a high voltage cut-off display circuit which indicates that the voltage of the battery 800 has exceeded a preset value and the vibratory compressor 100 has stopped.

As shown in FIG. 4, the phase control circuit 700 includes a reference voltage circuit 1, a switching detection circuit 2,
switching control circuit 3, pulse width determining circuit 4,
It is basically configured with a temperature detection circuit 5, and as required, a low-temperature cut-off circuit 6, a low-temperature cut-off display circuit 7, a low-voltage cut-off circuit 8, a low-voltage cut-off display circuit 9, and a high-voltage cut-off circuit 7. An off circuit 10 and a high voltage cut-off display circuit 11 are added, and the structure is such that the power can be cut off when the temperature, low voltage, or high voltage is reached.

FIG. 5 shows a circuit configuration of a specific embodiment of the phase control circuit, in which reference numeral 600 corresponds to that in FIG. 1 and 1 to 5 correspond to that in FIG. 4. Tr ₁ and Tr ₂ represent switching elements such as transistors, and the transistors Tr ₁ and Tr 2 represent switching elements such as transistors.
Tr ₂ repeats on and off alternately, Tr ₃ to Tr ₅ are transistors, and transistor Tr ₃
is for controlling the base current that determines the switching of transistors Tr ₁ and Tr ₂ , IC ₁ to IC ₄
is an integrated circuit, integrated circuit IC ₁ constitutes a flip-flop circuit, integrated circuit IC ₂ constitutes a constant voltage circuit, integrated circuit IC ₃ constitutes a differential circuit,
The integrated circuit IC ₄ constitutes a comparison circuit, D ₁ to D ₁₁ are diodes, R ₁ to R ₁₆ are resistors, C ₁ to C ₁₀ are capacitors, TH ₁ is a temperature detection element such as a thermistor, T ₁ is a transformer, W ₁ is transformer T ₁
The primary winding of transformer T 1, W ₂ is the secondary winding of transformer T ₁ , PW ₁
represent the drive coils of the vibratory compressor, respectively. It is also connected to the points in the figure or the points or corresponding points in FIGS. 6 to 8. The circuit operation will be explained below.

[] As shown in the illustrated polarity, the voltage of the DC power supply 800 (described below as a battery) is the voltage of the AC voltage generation circuit 6.
00 (described below in terms of the inverter circuit), the vibrating compressor 100 is in a steady operating state, and for example, the transistor Tr ₁ is in the saturation operating region and is maintained in the on state, and the transistor Tr ₁ and the It is assumed that the transistor Tr ₂ forming the circuit is in the cutoff region and is maintained in the off state. In this state (hereinafter referred to as state A), the DC voltage source is connected from the illustrated (+) terminal of the DC voltage source (battery 800) through the upper half of the primary winding W ₁ of the transformer T ₁ and the transistor Tr ₁ . A closed circuit is formed leading to the (-) terminal. A primary current flows in the upper half of the primary winding W ₁ of the transformer T ₁ in the direction of the arrow e in the figure. This primary current in the direction of the arrow e in the diagram causes the transformer to
A voltage is induced in the secondary winding _W2 of _T1 , and a drive current in the direction of arrow f is supplied to the drive coil _PW1 of the vibratory compressor. In the above state A, a voltage approximately twice the DC voltage source voltage is generated between the terminals a and b of the primary winding W ₁ of the transformer T ₁ with the polarity shown. From the terminal b of this primary winding W ₁ to the emitter of transistor Tr ₄ , the transistor Tr _{4
A closed circuit} ( _{temporarily closed} circuit _A current flows through the This current keeps the transistor Tr ₄ in the on state, and the collector current of the transistor Tr ₄ is supplied to the base of the transistor Tr ₁ to keep the transistor Tr ₁ in the on state. Also, the current flowing through the closed circuit A is the capacitor _C8 .
It is determined based on a time constant determined by the capacitance of R12 and the circuit resistance value (the resistance value of the resistor _R12 and the resistance values of other circuit elements).

[] Then, when the above transistor Tr ₁ satisfies the switch-off condition of I _C ≧h _FE・I _B (I _C : collector current, I _B : base current, h _FE : current amplification factor), the transistor Tr 1 The voltage drop between the collector and emitter _{of transformer T1 increases} rapidly, and
The applied voltage applied to the upper half of the next winding _W1 becomes approximately zero level. Therefore, the drive current in the direction of the arrow f in the figure to the drive coil PW ₁ of the vibratory compressor is cut off. Note that the change of the above transistor Tr ₁ from the off state to the on state is caused by the capacitor.
C ₂ , resistors R ₂ , R ₃ , and the switching detection circuit 2 that constitutes the differential circuit of the integrated circuit IC ₃ , and a trigger pulse signal is generated from the switching detection circuit 2 in response to the switching of the rising edge of the transistor Tr ₁ . is output, and the trigger pulse signal is input to the integrated circuit _IC1 .
As a result, the flip-flop circuit of the integrated circuit _IC1 outputs an "H" level, which causes a base current to flow through the transistor _Tr3 via the resistor _R1 . The transistor Tr ₃ is turned on, and the voltage at the point P shown in the diagram drops to the (-) terminal voltage of the DC voltage source, bypassing the base current of the transistor Tr ₁ and keeping the voltage at the point P shown in the diagram for a variable time width T' shown in FIG. 2. is maintained at the (-) terminal voltage.

[] During the above variable time T', transistors Tr ₁ and Tr ₄ are maintained in the off state, and
Transistor Tr ₂ paired with transistor Tr ₁
is still maintained in the off state for the above reason despite the on state of transistor Tr ₅ , which will be explained next, and the drive coil of the vibratory compressor
The drive current supplied to PW ₁ is maintained in a cut-off state. On the other hand, the capacitor _C8 , which had been charged according to the illustrated polarity, starts discharging, and the transistor _Tr5
The base current begins to flow through the transistor.
Tr ₅ remains on.

[] The variable time width T' is determined as follows. That is, when the transistor Tr ₃ is turned on, the collector of the transistor Tr ₃ drops to the potential of the (-) terminal of the DC voltage source, so the diode D ₄ becomes forward biased. Therefore, the illustrated point Z also has a low potential and the capacitor
The charge stored in C ₇ is gradually discharged through resistors R ₉ and R ₈ , and the potential at point Y in the figure also drops.

On the other hand, at the point X shown in the figure, a reference voltage at that temperature is set by the resistance value of the thermistor _TH1 , which is a temperature detection element, at that temperature and the respective values of the resistors _{R6 and R7} . capacitor
When the charge stored in C ₇ is discharged for the above reason and the potential at the point Y in the diagram becomes lower than the reference potential at the point X in the diagram, the output of the integrated circuit IC ₄ constituting the comparison circuit becomes The signal is inverted from "L" level to "H" level. This allows integrated circuits
The output of the flip-flop circuit of IC ₁ is “H”
The level is reversed to "L" level, and the base current of transistor _Tr3 stops flowing. That is, the transistor _Tr3 is turned off. Accordingly, the variable time width T' is determined.

Then, when the potential at the point P shown above rises, the collector current of the transistor Tr ₅ , which had been flowing to the DC voltage source (-) terminal via the resistor R ₁₅ , the diode D ₁ , the point P shown, and the transistor Tr ₃ , now changes. flows through the resistor _R15 to the base of the transistor _Tr2 . Transistor Tr ₂ is therefore switched on. Therefore, from the (+) terminal of the DC voltage source to the lower half of the primary winding W ₁ of the transformer T ₁ and the above transistor Tr ₂
A current begins to flow through the closed circuit that reaches the (-) terminal of the DC voltage source. That is, transformer
1 in the direction of arrow g shown in the diagram in the lower half of the primary winding of T _1.
Next, current begins to flow. Therefore, a drive current in the direction of the arrow h shown in the figure is now supplied to the drive coil PW ₁ of the vibratory compressor. The drive coil PW ₁ of the vibratory compressor is equipped with a transistor Tr ₂ .
The drive current continues to be supplied in the direction of arrow h in the figure until the switch-off condition is satisfied.

[] And transistor Tr ₂ is connected to the above switch.
When the off condition is satisfied, transistors Tr ₅ and Tr ₂ are switched off, and the above []
Thereafter, the same circuit operation as in the above case is performed, and the drive coil of the vibratory compressor is
The drive current supplied to PW ₁ is maintained in a cut-off state. Thereafter, similar operations are repeated, and an alternating voltage as shown in FIG. 2 is applied to the drive coil PW ₁ of the vibratory compressor.

To explain the increase or decrease in the conduction angle (phase angle) or conduction time width T shown in Figure 2, the higher the voltage between the (+) and (-) terminals of the DC voltage source, the more charge is charged in the capacitor _C7 . Because there will be more
Discharging via resistors R ₉ and R ₈ takes a long time. In other words, the voltage at the indicated point Y is the same as the voltage at the indicated point
The time required to reach the reference voltage becomes longer, and the time it takes for the transistor _Tr3 to turn off, that is, the variable time width T' becomes longer. Accordingly, the conduction angle or conduction time width T becomes shorter. When the voltage between the (+) and (-) terminals of the DC voltage source decreases, the variable time width T' becomes shorter, and the conduction angle or the conduction time width T becomes longer.

Also, as the temperature rises, the resistance of the thermistor TH ₁ of the temperature detection circuit 5 becomes smaller, and the thermistor TH1 of the temperature detection circuit 5 becomes smaller.
The combined resistance of TH ₁ and resistor R ₆ becomes small. Therefore, the reference voltage at point X in the diagram increases and the capacitor
The discharge time of C ₇ to reach the reference voltage becomes longer. That is, the conduction angle or conduction time width T becomes shorter. Conversely, when the temperature decreases, the conduction angle or conduction time width T
becomes longer.

FIG. 6 shows the circuit configuration of an embodiment of the low temperature cut-off circuit and low temperature cut-off display circuit according to the present invention. In the figure, 6 and 7 correspond to those in FIG. 4, IC ₅ is an integrated circuit and an OP amplifier, D ₁₂ is a diode, LED ₁ is a light emitting diode, and R ₁₈ to R ₂₀ are resistors. Also, by connecting the dots or the dots or corresponding points in FIG. 5, it has a low temperature cut-off function and a low temperature cut-off display function.

The reference voltage input to the non-inverting input terminal of the OP amplifier of integrated circuit IC ₅ and the voltage at point X in FIG. 5, which changes depending on the temperature of the input voltage input to the inverting input terminal, are compared, Temperature detection circuit 5
When the detected temperature falls below the preset value, the above
The output level of the OP amplifier changes from “L” level to “H”
Flip to level. The "H" level output of the OP amplifier is connected to the fifth point via diode _D12 .
The potential at point K in the figure is held at the "H" level. At the same time, the "H" level output of the OP amplifier is the light emitting diode of the low temperature cut/off display circuit 7.
Turn on LED ₁ . Since the output level of the integrated circuit IC ₄ is at the "H" level while the potential at the point K in the figure is maintained at the "H" level, the drive coil of the vibratory compressor is connected from the transformer _T1 as explained above.
No voltage is supplied to PW ₁ . and integrated circuits
The resistor R ₁₈ connected to the OP amplifier of IC ₅ provides hysteresis as shown in FIGS. 3A and 3B to prevent chattering.

FIG. 7 shows the circuit configuration of an embodiment of a low voltage cut-off circuit and a low voltage cut-off display circuit according to the present invention. In the figure, 8 and 9 correspond to those in Figure 4, IC ₆ is an integrated circuit, an OP amplifier, and D ₁₃
is a diode, LED ₂ is a light emitting diode, and R ₂₁ to R ₂₆ are resistors. Another point,,
By connecting the points , , , and the corresponding points in FIG. 5, it has a low voltage cut-off function and a low voltage cut-off display function.

A resistor R ₂₃ that changes in proportion to the reference voltage input to the non-inverting input terminal of the OP amplifier of integrated circuit IC ₆ and the voltage of the DC voltage source input to the inverting input terminal.
When the voltage of the DC voltage source becomes less than a preset value, the output level of the OP amplifier is inverted from the "L" level to the "H" level. Hereinafter, similar to the circuit configuration of an embodiment of the low temperature cut-off circuit and the low temperature cut-off display circuit shown in FIG. 7 above, a light emitting diode is used.
When LED ₂ is on, the vibratory compressor 100 is stopped. The resistor R ₂₂ prevents the low voltage chattering of FIG. 3C.

FIG. 8 shows the circuit configuration of an embodiment of a high voltage cut-off circuit and a high voltage cut-off display circuit according to the present invention. In the figure, 10 and 11 correspond to those in Figure 4, and IC ₇ is an integrated circuit with an OP amplifier,
D ₁₄ is a diode, LED ₃ is a light emitting diode, R ₂₇
or R ₃₂ represents resistance. Also point,
, , have a high voltage cut-off function and a high voltage cut-off function by connecting the points , , , and the corresponding points in FIG. 5, respectively.

A resistor R ₃₀ that changes in proportion to the reference voltage input to the inverting input terminal of the OP amplifier of integrated circuit IC ₇ and the voltage of the DC voltage source input to the non-inverting input terminal.
When the voltage of the DC voltage source exceeds a preset value, the output level of the OP amplifier is inverted from the "L" level to the "H" level. Below is the low voltage cut shown in Figure 7 above.
Similar to that described in the circuit configuration of an embodiment of the off-circuit and low-temperature cut-off display circuit, the light emitting diode
When the LED ₃ is lit, the vibratory compressor 100 is stopped. Resistor 28 prevents chattering at the high voltages of FIG. 3C.

As can be seen from the above description, the phase control circuit 700 shown in FIG. It is also possible. These five types of functions are: (a) a function to control the phase (conduction angle) of the alternating voltage supplied to the vibrating compressor 100 by the temperature detection circuit 5 for detecting the ambient temperature and/or evaporator temperature (and the cooling device (b) the alternating current supplied to the vibratory compressor 100 when the voltage of the DC voltage source applied to the inverter circuit 600 is high; The function of controlling the voltage phase (and the cooling device is the above-mentioned high voltage vibrating compressor 1)
(c) reducing the alternating voltage supplied to the vibratory compressor 100 when the ambient temperature and/or evaporator temperature drops below a preset temperature; stop it,
In addition, a function is provided to display that the vibratory compressor 100 is stopped because the temperature is below the set temperature, and to provide hysteresis for starting and stopping the vibrating compressor 100 to prevent chattering. In such cases, in order to prevent over-discharge of the battery, the alternating voltage supplied to the vibratory compressor 100 is stopped when the voltage falls below a preset voltage, and the alternating voltage supplied to the vibratory compressor 100 is stopped because the voltage is below the set voltage. The vibratory compressor 100
(e) When the voltage of the DC power supply 800 applied to the inverter circuit 600 is abnormally high, that is, when it exceeds a preset voltage, the vibration type The alternating voltage supplied to the compressor 100 is stopped, and since the voltage is higher than the set voltage, a message indicating that the alternating voltage is stopped is displayed, and hysteresis is provided for starting and stopping the vibratory compressor 100 to prevent chattering. This is a function to prevent this.

FIGS. 9A to 9F show voltage and current waveform diagrams in each circuit without and with phase control. Figure 9A shows the voltage waveform applied between the terminals of the drive coil PW ₁ of the vibratory compressor without phase control, and Figure 9B shows the drive coil PW ₁ of the vibratory compressor without phase control. The drive current waveform flowing in
FIG. 9C shows the trigger pulse signal waveform of the switching detection circuit 2 in the phase control circuit 700.
Figure D shows the base voltage waveform of the transistor Tr ₃ of the switching control circuit 3 in the phase control circuit 700, and Figure 9 E shows the voltage waveform applied between the terminals of the drive coil PW ₁ of the vibratory compressor when phase control is provided. , and FIG. 9F show the drive current waveforms flowing through the drive coil PW ₁ of the vibratory compressor in the case of phase control.

As explained above, according to the present invention, the phase of the alternating voltage supplied to the vibratory compressor is controlled based on the ambient temperature and/or the evaporator temperature and/or the high potential of the DC power supply applied to the inverter circuit. , the piston stroke is reduced as the ambient temperature and/or the evaporator temperature decreases and/or as the DC power supply potential applied to the inverter circuit becomes higher. Undesired damage can be prevented.

When the ambient temperature and/or evaporator temperature drops below a preset temperature, and/or
Or, when the voltage of the DC power supply is below or above a preset voltage, the alternating voltage supplied to the vibratory compressor is stopped, and an indication that the vibratory compressor is stopped because it is above or below the set value is displayed. In addition, the vibratory compressor is provided with hysteresis for starting and stopping, which prevents the vibratory compressor from being destroyed, and prevents chattering when starting and stopping near the set value, thereby preventing the vibratory compressor from starting or stopping near the set value. This will prevent the destruction of the If the DC power source is a battery, over-discharge is prevented, and the cause of the vibrating compressor's stoppage can be determined at a glance using the indicator light.

Further, according to the present invention, since the phase of the alternating voltage supplied to the vibratory compressor is controlled, the loss of electrical energy can be reduced compared to a method in which the amplitude of the alternating voltage is controlled.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram conceptually showing an embodiment of the cooling device of the present invention, Fig. 2 and Fig. 3 A, B, and C.
is an explanatory diagram for explaining the operation of the cooling device shown in FIG. 1, FIG. 4 is an example configuration of the phase control circuit shown in FIG. 1, and FIG. 5 is a specific example of the phase control circuit and AC voltage generation circuit. Example circuit configuration, FIGS. 6 to 8 show an example circuit configuration of a cut-off circuit and a display circuit, and FIG. 9 shows voltage and current waveform diagrams in each circuit with and without phase control, respectively. ing. In the figure, 100 is a vibratory compressor, 200 is a condenser, 300 is a strainer, 400 is a capillary tube, 500 is an evaporator, and 600 is a
AC voltage generation circuit (inverter circuit, oscillator), 700 is a phase control circuit, 800 is a DC power supply (battery), 900 is an electric wire, 1 is a reference voltage circuit, 2 is a switching detection circuit, 3 is a switching control circuit, 4 is a 5 is a temperature detection circuit; 6 is a low temperature cut-off circuit; 7 is a low-temperature cut-off display circuit; 8 is a low-voltage cut-off circuit; 9 is a low-voltage cut-off display circuit; 10 is a high-temperature cut-off circuit; A voltage cut-off circuit and 11 represent a high-voltage cut-off indicating circuit, respectively.

Claims (1)

[Claims] 1 AC voltage generation circuit that generates alternating voltage, the AC
DC to drive the voltage generation circuit and obtain alternating voltage
The natural vibration frequency of the mechanical system, which takes into consideration the elastic modulus of the power supply and refrigerant, and the vibration frequency of the electrical system due to the alternating voltage output from the AC voltage generation circuit are maintained in a substantially resonant state when driven. a condenser comprising a vibratory compressor, and into which the refrigerant output from the vibratory compressor is guided;
A capillary installed downstream of the capacitor
A cooling device comprising a tube and an evaporator provided downstream of the capillary tube, and configured to change the vibration frequency of the alternating voltage in accordance with fluctuations in the natural vibration frequency of the mechanical system, A phase control circuit is provided for controlling the phase of the alternating voltage supplied to the vibratory compressor based on the ambient temperature and/or evaporator temperature of the cooling device and/or the potential of the DC power source, and the phase control circuit A switching detection circuit that detects the switching point of the switching element provided in the AC voltage generation circuit, a switching control circuit that turns on and off the switching element, and a conduction angle of the switching element in response to the detection signal level of the cooling device. A cooling device comprising: a pulse width determining circuit for controlling the switching element; and a reference voltage circuit for supplying a reference voltage to the pulse width determining circuit for determining the conduction angle of the switching element.