JPH061990B2 - Vibration compressor power supply - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power supply device for a vibration type compressor, and more particularly to converting a DC voltage into an AC voltage having a predetermined frequency, and changing the vibration type compressor to the AC voltage. In the power supply device to be driven, in order to match the vibration period of the electric vibration system in the vibration type compressor with the natural vibration period of the mechanical vibration system, the frequency of the AC voltage is controlled. It relates to a power supply device.

[Problems to be solved by conventional technology and invention]

Small refrigerators for home use because of (1) simple structure, (2) small size and light weight, (3) small starting current, (4) high power factor, (5) low power consumption, etc. In addition, a vibration type compressor having a swing motor as a drive source as shown in FIG. 4 is used as a cooling device for a refrigerator in an automobile or a boat. Since the power source of the vibration type compressor used in the on-vehicle refrigerator of the above-mentioned automobile or boat (hereinafter referred to as vehicle) is obtained from the battery mounted in the vehicle, the DC voltage of the battery is converted into the AC voltage. An inverter for converting is used to drive the electromagnetic coil 1 in the vibration type compressor. The fourth
In the figure, reference numeral 1 is an electromagnetic coil, 2 is a ferrite magnet,
3 is an outer core, 4 is an inner core, and 5 is an annular magnetic gap.

As the above-mentioned inverter, a so-called transistor inverter utilizing switching characteristics of transistors is known. The switching control in the inverter is performed by using the following switching characteristics of the transistor. That is, when the collector current of the transistor is I _C , the base current is I _B , and the amplification factor is h _FE , the transistor is in a saturation region while I _C ≦ I _B × h _FE , but I _C ≧ It becomes an active region while I _B × h _FE . That is, the above-mentioned inverter is capable of generating a rectangular wave AC voltage by alternately turning on and off, for example, two transistors using this principle. Then, the output of the inverter is supplied to the electromagnetic coil 1 via a transformer (reference numeral 6 in FIG. 1) described later, and the electromagnetic coil 1 is indicated by an arrow in FIG.
The compressor is driven by driving up and down between the state (a) and the state (b). The output current i of the inverter when the electromagnetic coil 1 moves up and down is shown in FIG. 5, and it is known that the two transistors are switched at the arrows indicated by arrow (Patent application Sho) 55-31926).

In such a vibration type compressor, the electromagnetic coil 1 is used.
The frequency of the AC voltage applied to the (Figure 5 shown T _a,
It is desirable that T _b ) match the natural vibration period of the mechanical vibration system driven by the electromagnetic coil 1. However, in the conventional power supply device for the vibration type compressor,
There were the following problems.

(1) The base current I _B changes due to the voltage fluctuation of the DC power supply, and the switching timing of the transistor in the inverter fluctuates.

(2) switching transistors as described above, since those based on the amplification factor of the transistor (h _FE), must strictly perform management of the amplification factor (h _FE).

(3) Since the amplification factor (h _FE ) of the transistor changes over time and changes greatly with temperature, it is difficult to obtain the desired frequency due to the switching timing deviation.

[Means for solving problems]

The present invention is intended to solve the above problems, and therefore, the power supply device of the vibration type compressor of the present invention, an inverter circuit unit for converting direct current to alternating current by switching the switching transistor, A vibration type compressor constituted by an inverter control circuit for controlling the inverter circuit section, and a transformer having an input winding to which an output of the inverter circuit section is connected and an output winding connected to the vibration type compressor. , The step-like control reference voltage having a high voltage part at the head of the cycle and a stepwise low voltage part at the end of the cycle, and the voltage at the place corresponding to the output current of the inverter circuit part The above switch is compared with a wavy waveform voltage that has a peak in the middle of the rising cycle at the head and rises from the bottom state at the end of the cycle. The inverter control circuit includes a power supply voltage detection unit that detects the voltage level of the DC power supply, a temperature detection unit that detects the outside air temperature, and at least the power supply described above. A reference voltage generator that generates the control reference voltage by applying the voltage level of the low voltage portion of the control reference voltage based on the respective detection signals of the voltage detector and the temperature detector, and the output current of the inverter circuit portion. Output current detecting means for obtaining the above-mentioned wavy waveform voltage, comparing the detection voltage detected by the output current detecting means with a control reference voltage output from the reference voltage generating section, and controlling the detected voltage. The comparator that outputs a match signal when the reference voltage for use matches, and the match signal output from the comparator. Based on the above, a switching control unit for providing the switching timing of the switching transistor in the inverter circuit unit is provided.

Example of Invention

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

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram relating to the basic principle of the present invention, and FIGS. 3A to 3E are for explaining a control mode in the embodiment shown in FIG. FIG.

Prior to the description of the embodiment shown in FIG. 1, the basic principle of the present invention will be described with reference to FIG. In the embodiment shown in FIG. 1, the first and second switching transistors (hereinafter,
An alternating voltage is generated in the output winding 8 of the transformer 6 by alternately switching 10 and 11 (referred to simply as transistors), and the alternating voltage is applied to the electromagnetic coil 1 (shown in FIG. 4) of the vibration type compressor 9. It is well known that the voltage is applied. Then, the above-mentioned first and second transistors 1
The collector currents i of 0 and 11 have the current waveforms shown in FIG. 2 as described at the beginning of the present specification. Conventionally, the switching operation of the transistor is the fifth
Amplification factor of the transistor described above in connection with FIG. (H _FE) and method are performed based on the change of the corresponding base current (I _B) to, as Figure 2 illustrates, the so-called control reference voltage (arrow D It is known that the method is forcibly carried out based on. The waveform of the control reference voltage D in the latter method is composed of a high voltage section and a low voltage section (D 'in the figure) as shown in FIG. The transistor is switched at the intersection (point P in the figure) of the low-voltage portion D'and the current waveform i. The switching method of the transistor in the present invention is basically the latter method, but a stepwise waveform is obtained in the high voltage part and the low voltage part to obtain the control reference voltage. ing. The reason for providing the high voltage part is that the output current of the inverter rises at the head of the cycle and has a peak in the middle part of the cycle and rises from the bottom state at the end of the cycle as described with reference to FIG. This is to prevent undesired switching from occurring in the vicinity of the peak because the waveform voltage becomes a wavy waveform. Needless to say, the low voltage section is provided to provide a voltage level for performing the switching at a desired timing.

The present invention, which the so as to control the voltage level of the low pressure section is controlled to correspond to changes in the fluctuations and ambient temperature of the power supply voltage a voltage value V _t of the low-pressure portion D 'of the control reference voltage D is there. That is, by controlling the voltage value V _t , the frequency of the AC voltage supplied to the vibration type compressor can be made to follow the power supply voltage and the outside air temperature to be an optimum frequency. The operation of the embodiment shown in FIG. 1 constructed based on the above basic principle will be described below with reference to FIGS. 3 (A) to 3 (E). In addition,
3 (A) to (D) are arrows A to D shown in FIG.
The voltage waveform at the point, (E) shows the operation mode in the comparator 23 described later. Further, in FIG. 1, reference numeral 6 is a transformer, 7 is an input winding, 8 is an output winding, 9 is a vibration type compressor, and 10 and 11 are transistors, which constitute an inverter circuit portion according to the present invention. What to do, 1
Reference numeral 2 is an inverter control circuit, 13 is a control power supply unit that supplies a predetermined control voltage to the inverter control circuit, 14 is a temperature sensor that detects the outside air temperature, and 15 is a transistor control unit. For controlling the switching of the transistors 10 and 11, 1
6 is a waveform shaping unit, 17 and 23 are comparators, 18 is a power supply voltage detector, 19 is a temperature detector, 20 is a reference voltage generation unit for generating the above-mentioned control reference voltage, 21
Is a resistance for current detection, and 22 is an amplifier.

In FIG. 1, the waveform shaping section 16 outputs one of the outputs Q of the transistor control section 15 for controlling the switching of the transistors 10 and 11 (the output in the embodiment shown in FIG. 1) (FIG. 3 ( A) Illustration) 3rd
The data is shaped into a sawtooth waveform as shown in FIG. Then, the output B of the waveform shaping unit 16 in the comparator 17
And a predetermined V _t0 are compared with each other to output an original reference voltage C having a waveform shown in FIG. 3 (C) which is an original waveform of a control reference voltage D described later. Further, in the reference voltage generation unit 20, the original reference voltage C output from the comparator 17 is modified based on the contents of the power supply voltage detection unit 18 and the temperature detection unit 19, and is shown in FIG. A control reference voltage D having a waveform is generated. That is, for the zero voltage period in the original reference voltage C shown in FIG.
The control voltage D to which the voltage values V _t1 and V _t2 corresponding to the power supply voltage and the outside air temperature are added is generated. Further, the current i flowing in the input winding 7 of the transformer 6 is detected in the form of voltage by the current detection resistor 21 and sent to the comparator 23 via the amplifier 22. In the comparator 23, when the control reference voltage D and the current i are compared and substantially match as shown in FIG. 3 (E), a match signal is output to the transistor controller 15. That is, the output timing of the coincidence signal is indicated by arrows P ₁ , P ₂ , ... Shown in FIG. Then, the transistor control unit 15 inverts the output Q, by the coincidence signal output from the comparator 23, and switches the transistors 10 and 11. Therefore, the AC voltage supplied to the vibration type compressor has a required frequency without being affected by the fluctuation of the power supply voltage and the change of the outside air temperature, and the vibration type compressor 9 is driven under the optimum condition. Will be. In the embodiment shown in FIG. 1, the inverter circuit portion is composed of transistors, but by adopting the control system of the present invention, a MOS FET (voltage control type element) is used instead of the transistor. It is possible to configure the inverter circuit section.

〔The invention's effect〕

As described above, according to the present invention, it is possible to reduce the influence of the fluctuation of the power supply voltage and the change of the outside air temperature, and it is possible to drive the vibration type compressor under the optimum condition. In addition, MOS FET is used as the inverter component.
Since (voltage control type element) can be used, it is possible to contribute to cost reduction.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram relating to a basic principle of the present invention, and FIGS. 3A to 3E are explanatory diagrams of a control mode in the embodiment shown in FIG. FIG. 4 is a sectional view showing an example of a swing motor in a vibration type compressor, and FIG. 5 is a switching operation explanatory diagram of an inverter in a conventional power supply device of the vibration type compressor. In the figure, 6 is a transformer, 7 is an input winding, 8 is an output winding, 9 is a vibration type compressor, 10 and 11 are transistors, 12 is an inverter control circuit, 13 is a control power supply section, and 14 is a temperature sensor. , 15 is a transistor control unit, 16 is a waveform shaping unit, 17 and 23 are comparators, 18 is a power supply voltage detection unit,
Reference numeral 19 represents a temperature detection unit, 20 represents a reference voltage generation unit, 21 represents a current detection resistor, and 22 represents an amplifier.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Naoya Kawakami 3 Hayakawa, Niigata-cho, Nitta-cho, Nitta-gun, Gunma Sawafuji Electric Co., Ltd. Nitta Factory (72) Noriyoshi Yamada Nitta-cho, Nitta-gun, Gunma Large Hayakawa 3 Hayakawa Sawafuji Electric Co., Ltd. Nitta Factory (56) Reference JP 56-46685 (JP, A) JP 54-39843 (JP, A) JP 56-113076 (JP, A)

Claims (1)

[Claims] 1. An inverter circuit section for converting a direct current into an alternating current by switching a switching transistor, an inverter control circuit for controlling the inverter circuit section, and an input winding and a vibration to which an output of the inverter circuit section is connected. Oscillatory type compressor composed of a transformer having an output winding connected to a type compressor and having a high pressure part at the head of the cycle and a stepwise low pressure part at the end of the cycle For the reference voltage, and a voltage corresponding to the output current of the inverter circuit section, which has a peak at the middle of the rising cycle at the head of the cycle and a wavy waveform voltage rising from the bottom state at the end of the cycle. Are compared to determine the switching timing for switching the switching transistor. The inverter control circuit includes a power supply voltage detection unit that detects the voltage level of the DC power supply, a temperature detection unit that detects the outside air temperature, and a control signal for the control based on at least the detection signals of the power supply voltage detection unit and the temperature detection unit. A reference voltage generation unit that generates the control reference voltage by applying the voltage level of the low voltage portion of the reference voltage, an output current detection unit that obtains the wavy waveform voltage corresponding to the output current of the inverter circuit unit, the output current A comparator that compares the detection voltage detected by the detection means with the control reference voltage output from the reference voltage generation unit and outputs a coincidence signal when the detection voltage and the control reference voltage match; and The switching timing of the switching transistor in the inverter circuit is based on the coincidence signal output from the comparator. A power supply device for a vibration-type compressor, which is equipped with a switching control unit that provides a switching function.