JP3954669B2 - Vibration type compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a vibration type compressor such as a refrigerator.
[0002]
[Prior art]
Vibration type compressors are used in refrigerators and the like because of their simple structure, small size and light weight, high power factor, and low power consumption.
[0003]
FIG. 11 shows a cross-sectional view of a general linear motor for use in a vibration type compressor. 1 is a coil, 2 is a magnet, 3 is an external iron core, 4 is an internal iron core, and 5 is an annular magnetic circuit. In the vibration type compressor, the coil 1 is connected to a piston and supported by a resonance spring (shown in FIG. 1 described later), and an alternating current that resonates with a mechanical vibration system in order to improve efficiency. Voltage is supplied.
[0004]
In this type of vibration type compressor, the compression period in one cycle of the piston is shorter than the suction period. This is because the high pressure of the compressed refrigerant acts in the compression direction, and therefore the suction stroke is better than the compression stroke based on the position where the AC voltage is not applied (hereinafter referred to as the neutral position). Because it ’s big.
[0005]
FIG. 12 shows the displacement waveform of the piston. In FIG. 12, the positive direction is the compression direction, and the negative direction is the suction direction. Point a is the point with the maximum amplitude in the compression direction (hereinafter referred to as top dead center), and the coil 1 in FIG. 11 corresponds to the state of (a). Point b is the point where the amplitude in the inhalation direction is maximum (hereinafter referred to as bottom dead center), and the coil 1 corresponds to the state of (b).
[0006]
When such a mechanical vibration system that vibrates in a non-target manner is driven by a symmetrical current, the efficiency is deteriorated. For this reason, the vibration type compressor is designed to improve efficiency by controlling the time ratio between the compression period and the suction period in one cycle of the piston displacement and the time ratio between the positive half wave and the negative half wave of the current. An example is disclosed in Japanese Patent Publication No. 63-8315.
[0007]
Hereinafter, a drive circuit of a conventional vibration type compressor will be described with reference to FIG. In FIG. 13, 1 is a coil, 6, 7, 8, and 9 are main switch elements, and transistors 6, 8, 7, and 9, which are bridge-connected to each other, are alternately turned on and off alternately. Represent things. 10 and 11 are transistors for supplying current to the bases of the transistors 6 and 8 and 7 and 9 respectively, and 12 and 13 control collector currents of the transistors 21 and 20 respectively, that is, base currents of the transistors 10 and 11. Resistance.
Reference numerals 14 and 15 denote resistors for controlling the base currents of the transistors 7 and 8, respectively. Reference numerals 16, 17, 18 and 19 denote diodes which prevent reverse connection of the DC power supply and form a discharge circuit for the capacitor 23 as described later. To do. Reference numerals 20 and 21 denote detection switch elements, for example, transistors, which detect the charge / discharge current of the capacitor 23 and control the main switch elements 6 and 9 as described later.
[0008]
22 is a variable resistor that controls the charge / discharge current of a capacitor 23, which will be described later, 23 is a capacitor connected in parallel with the coil 1 via the detection switch elements 20 and 21, and 24 and 25 are diodes, respectively. Each of them forms a charging path for the capacitor 23. The detection switches 20 and 21, the capacitor 23, the resistor 22, and the diodes 24 and 25 constitute detection means.
[0009]
The operation of this conventional vibration type compressor will be described. As the capacitor 23 is charged, the main switch elements 6 and 8 are turned on, and a current flows through the coil 1 in the direction of the solid line in the figure.
[0010]
As the charging voltage of the capacitor 23 approaches the voltages at the terminals A and B, the collector current of the transistor 21 decreases, and the main switch elements 6 and 8 move from the saturation region to the active region.
[0011]
For this reason, the voltage between the terminals A and B decreases, and the capacitor 23 starts discharging. For this reason, the transistor 21 is rapidly turned off. Therefore, the main switch elements 6 and 8 are turned off, and the main switch elements 7 and 9 are turned on, so that a current flows through the coil in the direction of the broken line.
[0012]
By repeating the self-excited transmission operation described above, the coil 1 is supplied with an AC rectangular wave voltage having an operating frequency.
[0013]
[Problems to be solved by the invention]
However, in the conventional configuration, as the piston approaches the top dead center or the bottom dead center, the coil current or collector current (I _c ) And the main switch element is _C ≧ I _B × h _FE Then, using the fact that it is in the active region, the time ratio between the positive half wave and the negative half wave of the AC rectangular wave voltage of the operating frequency is adjusted to the time ratio between the compression period and the suction period of the piston displacement. Because of the load fluctuation of the vibration type compressor, I _C Due to fluctuations or ambient temperature fluctuations _FE Or the like, the difference in time ratio between the piston displacement and the AC rectangular wave voltage fluctuates, resulting in a problem that the efficiency of the vibration type compressor is lowered. In addition, there is a problem that the efficiency is lower than the sinusoidal wave driving because of the rectangular wave voltage driving at the operating frequency.
[0014]
The present invention solves the conventional problems and aims to increase the efficiency of a vibration type compressor.
[0015]
[Means for Solving the Problems]
In order to solve this problem, the present invention includes a displacement detector connected in the axial direction of a piston, an inverter circuit that converts a direct current into an alternating current by switching a transistor or the like, and applies a voltage to the coil, and a displacement detector. A top dead center position calculating means for calculating a top dead center position and a bottom dead center position from the piston position signal, and a compression period during one cycle of displacement of the piston from the top dead center position and the bottom dead center position. Piston displacement time ratio calculating means for calculating the time ratio between the suction period and the suction period, the time ratio between the compression period and the suction period, and the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit are equal. It is comprised from the inverter control means A controlled to become.
[0016]
Thereby, high efficiency of the vibration type compressor is realized.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The invention described in the claims of the present invention includes a cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and installed opposite to the magnet. A coil that acts on the magnet to move in the axial direction of the cylinder, a piston that is connected to the coil and moves in the cylinder in the axial direction, a resonance spring that is connected to the piston, and an axial direction of the piston From a displacement detector, a converter circuit that converts alternating current power to direct current power, an inverter circuit that converts direct current to alternating current by switching a transistor or the like and applies a voltage to the coil, and a piston position signal from the displacement detector Top dead center bottom dead center position calculating means for calculating the top dead center and bottom dead center position of the piston, and the top dead center position which is a difference between the top dead center position and a preset top dead center reference value A top dead center position comparing means for outputting a comparison signal; and a piston displacement time ratio calculating means for calculating a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position. And if the top dead center reference value is greater than the top dead center position by the top dead center position comparison signal, the output voltage of the inverter circuit is increased, and the top dead center reference value is increased from the top dead center position. Inverter control for reducing the output voltage when it is smaller and controlling the time ratio between the compression period and the suction period to be equal to the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit The top dead center and bottom dead center position calculating means calculates the top dead center position and bottom dead center position of the piston from the piston position signal from the displacement detector. Operate, Serial piston displacement time ratio calculating means for calculating a time ratio of a compression period and the intake period of one cycle of the piston from the top dead center position and a bottom dead center position.
[0018]
Then, the inverter control means A controls the inverter circuit so that the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit is equal to the time ratio between the compression period and the suction period. It has the effect | action of controlling (Width Modulation).
[0019]
According to the second aspect of the present invention, a cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and a magnet opposed to the magnet, and installed in the magnet A coil that moves in the axial direction of the cylinder by acting, a piston that is connected to the coil and moves in the cylinder in the axial direction, a resonance spring that is connected to the piston, and a displacement detection that is connected in the axial direction of the piston A converter circuit that converts AC power directly into power, an inverter circuit that converts DC to AC by switching a transistor, etc., and applies a voltage to the coil, and a piston position signal from the displacement detector Top dead center position calculating means for calculating top dead center and bottom dead center positions, and top dead center position comparison that is a difference between the top dead center position and a preset top dead center reference value And a piston displacement time ratio calculating means for calculating a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position; A current detector for detecting a current flowing through the coil; and a current waveform time ratio calculating means for calculating a time ratio between a positive half wave period and a negative half wave period of the coil current from a current waveform signal from the current detector. A time ratio comparison means for outputting a time ratio comparison signal that is a difference between a time ratio of the compression period of the piston displacement and a time ratio of a half-wave period corresponding to the compression period of the coil current, and the top dead center When the top dead center reference value is larger than the top dead center position by the position comparison signal, the output voltage of the inverter circuit is increased, and when the top dead center reference value is smaller than the top dead center position, the output voltage Decrease When the time ratio of the compression period of the piston displacement is greater than the time ratio of the half-wave period corresponding to the compression period of the coil current, the compression ratio of the output voltage of the inverter circuit is determined by the time ratio comparison signal. The time ratio of the corresponding half-wave period is increased by a reference ratio, and the time ratio of the compression period of the piston displacement is smaller than the time ratio of the half-wave period corresponding to the compression period of the coil current. And the inverter control means B for controlling the time ratio of the half-wave period corresponding to the compression period of the output voltage to be reduced by the reference ratio, and the current waveform time ratio calculation Means calculates a time ratio between a positive half-wave period and a negative half-wave period of the coil current from a current waveform signal from the current detector, and the piston displacement time A ratio calculation means calculates a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position.
[0020]
Next, the time ratio comparison means outputs a time ratio comparison signal that is the difference between the time ratio of the compression period of the piston displacement and the time ratio of the half-wave period corresponding to the compression period of the coil current.
[0021]
When the inverter control means B determines that the time ratio of the compression period of the piston displacement is larger than the time ratio of the half-wave period corresponding to the compression period of the coil current according to the time ratio comparison signal, the inverter circuit The time ratio of the half wave period corresponding to the compression period of the output voltage is increased by the reference ratio, and the time ratio of the compression period of the piston displacement is the time ratio of the half wave period corresponding to the compression period of the coil current. If smaller, the PWM control is performed so that the time ratio of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit is reduced by the reference ratio.
[0022]
According to a third aspect of the present invention, there is provided a cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and opposed to the magnet and installed in the magnet. A coil that moves in the axial direction of the cylinder by acting, a piston that is connected to the coil and moves in the cylinder in the axial direction, a resonance spring that is connected to the piston, and a displacement detection that is connected in the axial direction of the piston A converter circuit that converts alternating current power to direct current power, an inverter circuit that converts direct current to alternating current by switching a transistor and the like, and applies a voltage to the coil, and a piston position signal from the displacement detector Top dead center position calculating means for calculating top dead center and bottom dead center positions, and top dead center position comparison that is a difference between the top dead center position and a preset top dead center reference value A top dead center position comparing means for outputting a signal, a current detector for detecting a current flowing through the coil, a current value calculating means for calculating an average current value from a current waveform signal from the current detector, and the current Current value comparing means for storing a current value and comparing the current value stored this time with the current current value and outputting a current value comparison signal; and the top dead center position from the top dead center position by the top dead center position comparison signal. When the point reference value is larger, the output voltage of the inverter circuit is increased. When the top dead center reference value is smaller than the top dead center position, the output voltage is decreased, and the current value comparison signal causes the inverter to An oscillating pressure comprising an inverter control means C for controlling the current value to be minimized by increasing or decreasing the time ratio between the positive half wave period and the negative half wave period of the output voltage of the circuit by the reference ratio. The current value calculation means calculates an average current value from the current waveform signal from the current detector, and the current value comparison means stores the current value and stores it last time. The current value is compared with the current value, and a current value comparison signal is output.
[0023]
Then, the inverter control means C increases or decreases the time ratio between the positive half-wave period and the negative half-wave period of the output voltage of the inverter circuit by the reference ratio by the current value comparison signal to minimize the current value. Thus, the PWM control is performed.
[0024]
A vibration type compressor according to a first embodiment of the present invention will be described below with reference to FIGS.
[0025]
1 is a cross-sectional view of a vibration type compressor according to a first embodiment of the present invention, FIG. 2 is an electric circuit diagram according to the embodiment, FIG. 3 is an operation waveform diagram of an inverter circuit according to the embodiment, and FIG. Is an operation flowchart in the embodiment, and FIG. 5 is an operation time chart in the embodiment.
[0026]
In FIG. 1, a cylindrical cylinder 27 is provided at the center of a vibration type compressor 26, and a permanent magnet 28 is arranged around the cylinder 27 in an annular shape. An annular coil 1 is installed between the permanent magnet 2 and the cylinder 27 and acts on the permanent magnet 2 to move in the axial direction of the cylinder 27.
[0027]
The compression piston 14 is accommodated in the cylinder 27, forms a compression chamber 33 having a suction valve 31 and a discharge valve 32, and is connected to the coil 1 to move in the cylinder 27 in the axial direction. The suction valve 31 and the discharge valve 32 are connected to a suction pipe 34 and a discharge pipe 35, respectively. Reference numeral 36 is a resonance spring, and 37 is a displacement detector comprising a differential transformer or the like connected in the axial direction of the piston 14.
[0028]
A magnetic field by the permanent magnet 2 is formed between the permanent magnet 2 and the cylinder 27. When an alternating current is supplied to the coil 1 disposed between the permanent magnet 2 and the cylinder 27, the frequency of the supplied alternating current is supplied to the coil 1. The piston 14 connected to the coil 1 is driven in the axial direction.
Next, the electric circuit shown in FIG. 2 will be described. Reference numeral 38 denotes a commercial AC power supply, which is connected to an AC input unit of a converter circuit 39 that converts AC to DC. The converter circuit 39 is composed of four diodes 39a, 39b, 39c, and 39d, and is connected to a connection point between the anode of the diode 39a and the cathode of 39d and a connection point between the anode of the diode 39b and the cathode of 39c, respectively. The commercial AC power supply 38 is connected. The cathode of the diode 39a and the cathode of the 39b are connected, and the anode of the diode 39c and the anode of the 39d are connected.
[0029]
Reference numeral 40 denotes a smoothing circuit, which includes two electrolytic capacitors 40a and 40b. The connection point of the diodes 39a and 39b and the positive electrode side of the electrolytic capacitor 40a are connected, the connection point of the diodes 39b and 39c and the negative electrode side of the electrolytic capacitor 40a are connected, and the connection point of the diodes 39c and 39d and the The negative electrode side of the electrolytic capacitor 40b is connected.
[0030]
The positive side of the electrolytic capacitor 40a is connected to the collector of the transistor TR1 in the inverter circuit 41 and the cathode of the diode D1, and the negative side of the electrolytic capacitor 40a is connected to the positive side of the electrolytic capacitor 40b. The vibration type compressor 26 is connected to one of the coils 1 (A in the figure). The negative electrode side of the electrolytic capacitor 40b is connected to the emitter of the transistor TR2 and the anode of the diode D2 in the inverter circuit 41.
[0031]
In the inverter circuit 41, the emitter of the transistor TR1, the collector of the transistor TR2, the anode of the diode D1, and the connection point of the diode D2 are connected to the electrolytic capacitor 40a of the coil 1 of the signal compressor 26. It is connected to the side not shown (B in the figure). TR1 is driven by a PWM signal from an upper arm drive circuit 42 described later, and TR2 is driven by a PWM signal from an arm transistor 43 described later.
[0032]
FIG. 3 shows an operation waveform diagram of the inverter circuit 41. FIGS. 3 (a) and 3 (b) are a TR1 drive signal and a TR2 drive signal, respectively. TR2 is in an OFF state during a half period when TR1 is turned ON / OFF by a PWM signal, and vice versa during a subsequent half period. It is.
[0033]
FIG. 3C shows the output voltage of the inverter circuit 41 and is supplied between A and B of the coil 1 of the vibration type compressor 26. The solid line in FIG. 3 (c) is the PWM output amplified to TR1 and TR2, and a large number of pulse trains with a carrier cycle are created in the output waveform of the operation cycle, and the equivalent voltage (illustrated with a broken line) of the pulse width is sinusoidal. To change.
[0034]
In order to change the output voltage (equivalent voltage, the same applies hereinafter) of the inverter circuit 41, the pulse width of the PWM signal may be changed, and the time ratio between the positive half wave and the negative half wave in one cycle of the output voltage is changed. The time ratio between the on / off period of the TR1 PWM signal and the on / off period of the TR2 PWM signal may be changed.
[0035]
Reference numeral 37 denotes a displacement detector composed of a differential transformer or the like connected in the axial direction of the piston 30, and the analog position signal of the piston 30 from the displacement detector 37 is passed through the first A / D converter 44. It is converted into a digital signal and input to the top dead center / bottom dead center position calculation means 45.
[0036]
The top dead center and bottom dead center position calculating means 45 calculates the top dead center position and bottom dead center of the piston 30. Reference numeral 46 denotes a top dead center position comparison means, which outputs a top dead center position comparison signal, which is a difference between the top dead center position and a preset top dead center reference value, to an inverter control means A47 described later. 48 is a piston displacement time ratio calculation means, which is a displacement within one cycle of displacement of the piston 30. A compression period from the bottom dead center position to the top dead center position and a suction period from the top dead center to the bottom dead center. Is output to the inverter control means A47.
[0037]
The inverter control means A47 is constituted by a PWM waveform generation means A49, the upper arm drive circuit 42, and the lower arm drive circuit 43. The waveform generation means A49 is determined from the top dead center position by the top dead center position comparison signal. When the top dead center reference value is larger, the output voltage of the inverter circuit 41 is increased by a preset reference voltage value, and when the top dead center reference value is smaller than the top dead center position, the output voltage is decreased by the reference voltage value. As described above, the PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43, and the time ratio between the compression period and the suction period and the positive half wave and the negative half wave of the output voltage of the inverter circuit The PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so that the time ratio is equal.
[0038]
The operation of the vibration type compressor configured as described above will be described below based on the flowchart of FIG. 4 and the timing chart of FIG.
[0039]
In step 1, the commercial AC power supply 22 is turned on. The electrolytic capacitor 40 is charged via the converter circuit 39 and DC power is supplied to the inverter circuit 41. The PWM signal is output from the upper arm drive circuit 42 and the lower arm drive circuit 43, and the OFF state body is repeated during a half cycle in which TR1 and TR2 of the inverter circuit 41 are alternately turned on and off by the PWM signal.
[0040]
An output voltage obtained by converting direct current into alternating current from the inverter circuit 41 is supplied to the coil 1 of the vibration type compressor 26, the vibration type compressor 26 starts operation, and the piston 30 connected to the coil 1 is The cylinder 27 vibrates in the axial direction according to the frequency of the output voltage, and the refrigerant is compressed in the compression chamber 33.
[0041]
The operation frequency and pulse width of the PWM signal immediately after the commercial AC power supply 22 is turned on, and the time ratio of the positive half wave and negative half wave of the output voltage of the inverter circuit 41 are predetermined values.
[0042]
In step 2, the analog position signal of the piston 30 from the displacement detector 37 is converted into a digital signal via the A / D converter 44 and input to the top dead center / bottom dead center position calculation means 45. . This signal indicates the upper end position of the piston 30 facing the compression chamber 33, and this is A. A is set to 0 immediately after the power is turned on.
[0043]
Next, at step 3, the top dead center position B which is the maximum value of the upper end position of the piston 30 is calculated in the top dead center bottom dead center position calculating means 45 as shown in the cycle 1a of FIG.
[0044]
In step 4 and step 5, a top dead center reference value is obtained by a top dead center position comparison signal which is a difference between the top dead center position B from the top dead center position comparison means 46 and a preset top dead center reference value C. If C is larger than the top dead center position B, the process proceeds to step 6, and the PWM waveform generating means A49 increases the upper arm so that the inverter output voltage V is increased by the reference voltage E as shown in the cycle 2b of FIG. The PWM waveform is output to the drive circuit 42 and the lower arm drive circuit 43.
[0045]
If the top dead center reference value C and the top dead center position B are the same, the process proceeds to step 7, and the inverter output voltage V holds the current voltage as shown in the cycle 4b of FIG.
[0046]
On the other hand, if the top dead center reference value C is smaller than the top dead center position B, the process proceeds to step 8 where the PWM waveform generating means A49 reduces the inverter output voltage V by the reference voltage D (not shown). PWM waveforms are output to the upper arm drive circuit 42 and the lower arm drive circuit 43.
[0047]
Immediately after power-on, steps 2, 3, 4, and 6 are repeated to gradually increase the inverter output voltage. As the inverter output voltage increases, the stroke of the piston 30 increases, and when the top dead center position B of the piston 30 becomes equal to the top dead center reference value C as shown in the cycle 3a, the process proceeds to step 7, where the inverter output voltage Are maintained at the same voltage, and the process proceeds to step 9.
[0048]
In step 9, the compression period from the bottom dead center position D to the top dead center position B in the displacement of one cycle of the piston 30 as shown in the cycle 4a in FIG. The time ratio α for one cycle is calculated.
[0049]
Next, the process proceeds to step 10, where the PWM waveform generating means A determines whether the time ratio α: (1-α) between the compression period and the suction period and the output voltage of the inverter circuit 47 are positive as shown in the cycle 5b of FIG. PWM waveform signals are output to the upper arm drive circuit 42 and the lower arm drive circuit so that the time ratios of the half wave and the negative half wave are equal.
[0050]
Then, after performing Step 6 or Step 8 or Step 9, the process returns to Step 2 to repeat a series of operations.
[0051]
As described above, in the vibration type compressor of the present embodiment, the top dead center and bottom dead center position calculating means 45 uses the piston position signal from the displacement detector 37 to detect the top dead center position and the bottom dead center of the piston 30. The piston displacement time ratio calculating means 48 calculates a time ratio between the compression period and the suction period in one cycle of the piston 30 from the top dead center position and the bottom dead center position, and calculates the inverter control. Means A47 performs PWM control of the inverter circuit 41 so that the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit 41 is equal to the time ratio between the compression period and the suction period. Have
[0052]
Therefore, the time ratio between the compression period and the suction period of the piston 30 and the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit 41 can be accurately matched, and the vibration-type compression The efficiency of the machine 26 can be increased.
[0053]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned.
[0054]
Next, a second embodiment of the present invention will be described with reference to the drawings. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
[0055]
FIG. 6 is an electric circuit diagram according to the second embodiment of the present invention, and FIG. 7 is an operation flowchart according to the second embodiment.
[0056]
In FIG. 6, reference numeral 50 denotes a current detector, which is inserted between the coil 1 and the intersection of the electrolytic capacitor 40a and the electrolytic capacitor 40b and flows through the coil 1 (the direction of the arrow shown in the figure is positive). ) Is detected.
[0057]
The analog current signal from the current detection sensor 50 is converted into a digital current waveform signal via the second A / D converter 51 and input to the current waveform time ratio calculation means 52. The current waveform time ratio calculating means 52 calculates a time ratio between the positive half wave period and the negative half wave period of the coil current from the current waveform signal.
[0058]
53 is a time ratio comparison means, and an inverter control to be described later is a time ratio comparison signal which is a difference between the time ratio of the compression period of the piston displacement and the time ratio of the positive half wave period corresponding to the compression period of the coil current. Output to means B54.
[0059]
The inverter control means B54 is constituted by a PWM waveform generation means B55, the upper arm drive circuit 42, and the lower arm drive circuit 43. The waveform generation means B55 is determined from the top dead center position by the top dead center position comparison signal. When the top dead center reference value is larger, the output voltage of the inverter circuit 41 is increased by a preset reference voltage value, and when the top dead center reference value is smaller than the top dead center position, the output voltage is decreased by the reference voltage value. As described above, the PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43, and the time ratio of the compression period of the piston displacement is set to the compression period of the coil current by the time ratio comparison signal. When the time ratio of the corresponding positive half-wave period is larger than the time ratio of the positive half-wave corresponding to the compression period of the output voltage of the inverter circuit 41 When the time ratio of the compression period of the piston displacement is smaller than the time ratio of the half-wave period corresponding to the compression period of the coil current, the output voltage of the inverter circuit 41 is increased. PWM waveform signals are output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so that the time ratio of the positive half wave period corresponding to the compression period is reduced by the reference ratio.
[0060]
The operation of the vibration type compressor configured as described above will be described below with reference to the flowchart of FIG. 7 and the timing chart of FIG.
[0061]
In step 101, the commercial AC power supply 38 is turned on. Next, in step 102, the same processing as the processing from step 2 to step 8 (hereinafter referred to as top dead center control) described in the timing chart of FIG. 4 of the first embodiment is performed, and in cycle 11a of FIG. As shown, when the top dead center position B of the piston 30 becomes equal to the top dead center reference value C, the inverter output voltage is held at the same voltage, and the routine proceeds to step 103.
[0062]
In step 103, the piston position time ratio calculating means 48 is a compression period from the bottom dead center position D to the top dead center position B in one cycle of displacement of the piston 30, as shown in the cycle 11a of FIG. The time ratio α for one cycle is calculated.
[0063]
Next, in step 104, the current waveform calculation means 52 calculates a time ratio γ for one cycle of the positive half-wave period in one cycle of the coil current from the current waveform signal, as shown in the cycle 11C of FIG. To do.
[0064]
Next, in step 105 and step 106, the time ratio comparing means 53 compares the time ratio α of the compression period of the piston displacement with the time ratio γ of the half-wave period corresponding to the compression period of the coil current. By outputting the time ratio comparison signal, if the time ratio α of the compression period is smaller than the time ratio γ of the positive half wave of the coil current, the process proceeds to step 107, as shown in the cycle 12b of FIG. PWM waveform signals are output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so that the time ratio β of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is reduced by the reference ratio e. To do.
[0065]
If the time ratio α of the compression period is the same as the time ratio γ of the positive half wave of the coil current, the process proceeds to step 108, and the time of the positive half wave period of the output voltage as shown in the cycle 14B of FIG. The ratio β holds the current time ratio.
[0066]
If the time ratio α of the compression period is larger than the time ratio γ of the positive half wave period of the coil current, the process proceeds to step 109, and the time ratio β of the positive half wave period of the output voltage is set to a reference ratio e. The PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to be increased only by a large amount (not shown).
[0067]
Then, after performing Step 107, Step 108, or Step 109, the process returns to Step 102 to repeat a series of operations.
[0068]
As described above, in the vibration type compressor according to the present embodiment, the time ratio comparison unit 53 has the time ratio of the compression period of the piston displacement and the time ratio of the half-wave period corresponding to the compression period of the coil current. The inverter control means B54 calculates the time ratio of the piston displacement compression period corresponding to the compression period of the coil current according to the time ratio comparison signal. When the time ratio is larger than the time ratio, the time ratio of the positive half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is increased by the reference ratio, and the time ratio of the compression period of the piston displacement is greater than the coil current. Is smaller than the time ratio of the positive half-wave period corresponding to the compression period, the time ratio of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is reduced by the reference ratio. Has the effect that PWM control so that.
[0069]
For this reason, it is possible to accurately match the time ratio between the compression period and the suction period of the piston 30 with the time ratio between the positive half wave and the negative half wave of the coil current that is a direct drive source of the piston 30. The vibration type compressor 26 can be made more efficient than the time ratio between the compression period and the suction period of the piston 30 and the time ratio between the positive half wave and the negative half wave of the output voltage. be able to.
[0070]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned. The time ratio between the zero compression period and the suction period and the time ratio between the positive half wave and the negative half wave of the coil current that is a direct drive source of the piston 30 can be accurately matched. The vibration type compressor 26 can be made more efficient than the time ratio between the compression period and the suction period and the time ratio between the positive half wave and the negative half wave of the output voltage.
[0071]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned.
[0072]
Next, a third embodiment of the present invention will be described with reference to the drawings. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
[0073]
FIG. 9 is an electric circuit diagram according to the third embodiment of the present invention. In FIG. 9, reference numeral 56 denotes current value calculation means, which calculates an average current value from the current waveform signal. Reference numeral 57 denotes current value comparison means for storing the current value, comparing the current value stored last time with the current value, and outputting a current value comparison signal.
[0074]
Reference numeral 58 denotes inverter control means C, which comprises a PWM waveform generation means C59, the upper arm drive circuit 42, and the lower arm drive circuit 43. The waveform generation means C59 receives the top dead center position by the top dead center position comparison signal. When the top dead center reference value is larger than the point position, the output voltage of the inverter circuit 41 is increased by a preset reference voltage value, and when the top dead center reference value is smaller than the top dead center position, the reference voltage value A PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to decrease by minutes, and a positive half wave period and a negative half wave of the output voltage of the inverter circuit 41 are determined by the current value comparison signal. The upper arm drive circuit 42 and the lower arm are set so that the current value is minimized by increasing or decreasing the time ratio with the period by the reference ratio. And outputs a PWM waveform signal to arm drive circuit 43.
[0075]
The operation of the vibration type compressor configured as described above will be described below with reference to the flowchart of FIG.
[0076]
In step 201, the commercial AC power supply 38 is turned on. Next, in step 202, the same processing as the processing from step 2 to step 8 (hereinafter referred to as top dead center control) described in the timing chart of FIG. When the position B becomes equal to the top dead center reference value C, the inverter output voltage is held at the same voltage, and the process proceeds to step 203.
[0077]
In step 203, the current value calculating means 56 calculates an average current value i from the current waveform signal, and in step 204, the current value comparing means 57 converts the current value i to the minimum current value i. _min Remember as.
[0078]
Next, the routine proceeds to step 205, where the upper arm drive circuit 42 and the lower arm drive circuit are set so as to reduce the time ratio β of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 by the reference ratio e. The PWM waveform signal is output to 43.
[0079]
Next, in step 206, the current value calculation means 56 calculates an average current value i from the current waveform signal, and in step 207, the current value comparison means 57 calculates the current value i and the minimum current value i. _min If the current value i is smaller, the process proceeds to step 208, where the current value i is changed to the minimum current value i. _min Remember as.
[0080]
Next, the routine proceeds to step 209, where the upper arm drive circuit 42 and the lower arm drive circuit are set so that the time ratio β of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is reduced by the reference ratio e. The PWM waveform signal is output to 43.
[0081]
Next, in step 210, the current value calculation means 56 calculates an average current value i from the current waveform signal, and in step 211, the current value comparison means 57 calculates the current value i and the minimum current value i. _min If the current value i is smaller, the process proceeds to step 208, where the current value i is changed to the minimum current value i. _min And return to step 209 again, where the current value i is the minimum current value i. _min Until it becomes larger, the upper arm drive circuit 42 and the lower arm drive circuit 43 are set so that the time ratio β of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is reduced by the reference ratio e. The process of outputting the PWM waveform signal is continued.
[0082]
In step 211, the current value i is changed to the minimum current value i. _min If larger, the process proceeds to step 213, where the upper arm drive circuit 42 and the lower arm drive circuit 42 and the lower arm drive circuit 42 so that the time ratio β of the positive half wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is increased by the reference ratio e. The PWM waveform signal is output to the arm drive circuit 43, the current value i is set to the minimum current value, and the process returns to step 202.
[0083]
On the other hand, in step 207, the current value comparing means 57 makes the current value i and the minimum current value i. _min If the current value i is larger, the process proceeds to step 214 so that the time ratio β of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is increased by the reference ratio e. The PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43.
[0084]
Next, in step 215, the current value calculation means 56 calculates an average current value i from the current waveform signal, and in step 216, the current value comparison means 57 calculates the current value i and the minimum current value i. _min If the current value i is smaller, the process proceeds to step 217, where the current value i is reduced to the minimum value i. _min And return to step 214 again, and the current value i is the minimum current value i. _min Until it becomes larger, the arm drive circuit 42 and the lower arm drive circuit 43 are made to increase the time ratio β of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 by the reference ratio e. The process of outputting the PWM waveform signal is continued.
[0085]
In step 216, the current value i is the minimum value i. _min If larger, the process proceeds to step 218, where the upper arm drive circuit 42 and the lower arm drive circuit 42 and the lower arm drive circuit 42 so that the time ratio β of the positive half wave period corresponding to the compression period of the output voltage of the inverter circuit 41 is reduced by the reference ratio e. The PWM waveform signal is output to the arm drive circuit 43, the current value i is set to the minimum current value, and the process returns to step 202.
[0086]
As described above, in the vibration type compressor of this embodiment, the current value calculation unit 56 calculates an average current value from the current waveform signal from the current detector 50, and the current value comparison unit 57 The current value is stored, the current value stored last time is compared with the current value, and a current value comparison signal is output.
[0087]
Then, the inverter control means C58 increases or decreases the time ratio between the positive half wave period and the negative half wave period of the output voltage of the inverter circuit by a reference ratio according to the current value comparison signal, thereby minimizing the current value. Thus, the PWM control is performed.
[0088]
For this reason, the time ratio between the positive half wave and the negative half wave of the output voltage can be controlled so that the input power of the vibration type compressor 26 is always minimized, and the compression period and the suction period of the piston 30 can be controlled. And the time ratio between the positive half wave and the negative half wave of the coil current, which is a direct drive source of the piston 30, are further improved in efficiency of the vibration type compressor 26. be able to.
[0089]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned.
[0090]
【The invention's effect】
As described above, the present invention provides a cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and opposed to the magnet and acting on the magnet. A coil that moves in the axial direction of the cylinder, a piston that is connected to the coil and moves in the cylinder in the axial direction, a resonance spring that is connected to the piston, and a displacement detector that is connected in the axial direction of the piston A converter circuit that converts alternating current power to direct current power, an inverter circuit that converts direct current to alternating current by switching a transistor or the like and applies a voltage to the coil, and a piston position signal from the displacement detector A top dead center position calculating means for calculating a top dead center and a bottom dead center position, and a top dead center position comparison signal that is a difference between the top dead center position and a preset top dead center reference value. A piston displacement time ratio calculating means for calculating a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position; When the top dead center reference value is greater than the top dead center position by the top dead center position comparison signal, the output voltage of the inverter circuit is increased, and the top dead center reference value is greater than the top dead center position. Inverter control means A that reduces the output voltage when it is small and controls the time ratio between the compression period and the suction period and the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit to be equal. Can accurately match the time ratio between the compression period and the suction period of the piston and the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit, and the vibration type It is possible to achieve high efficiency of the compressor.
[0091]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned.
[0092]
Further, a cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and installed opposite to the magnet and acting on the magnet, the shaft of the cylinder A coil that moves in a direction, a piston that is connected to the coil and moves in the cylinder in the axial direction, a resonance spring that is connected to the piston, a displacement detector that is connected in the axial direction of the piston, A converter circuit for converting to electric power, an inverter circuit for converting a direct current to an alternating current by switching a transistor or the like and applying a voltage to the coil, and a top dead center and a bottom dead center of the piston from a piston position signal from the displacement detector Top dead center position calculating means for calculating a position, and a top dead center position comparison signal that is a difference between the top dead center position and a preset top dead center reference value Position comparing means, piston displacement time ratio calculating means for calculating a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position, and a current flowing through the coil A current detector for detecting, a current waveform time ratio calculating means for calculating a time ratio between a positive half wave period and a negative half wave period of the coil current from a current waveform signal from the current detector, and compression of the piston displacement A time ratio comparison means for outputting a time ratio comparison signal that is a difference between a time ratio of a period and a time ratio of a half-wave period corresponding to the compression period of the coil current; and the top dead center position comparison signal The output voltage of the inverter circuit is increased when the top dead center reference value is larger than the point position, and the output voltage is decreased when the top dead center reference value is smaller than the top dead center position. If the time ratio of the compression period of the piston displacement is greater than the time ratio of the half-wave period corresponding to the compression period of the coil current by the time ratio comparison signal, the half-end corresponding to the compression period of the output voltage of the inverter circuit When the time ratio of the period is increased by a reference ratio, and the time ratio of the compression period of the piston displacement is smaller than the time ratio of the half-wave period corresponding to the compression period of the coil current, the output voltage of the inverter circuit is compressed By providing inverter control means B that controls the time ratio of the half-wave period corresponding to the period to be reduced by the reference ratio, the time ratio between the compression period and the suction period of the piston and the direct drive of the piston The time ratio between the positive half wave and the negative half wave of the coil current that is the source can be accurately matched, and the time between the compression period and the suction period of the piston It is possible to further increase the efficiency of the vibration type compressor as compared with the time ratio and the time ratio between the positive half wave and the negative half wave of the output voltage.
[0093]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned.
[0094]
Further, a cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and installed opposite to the magnet and acting on the magnet, the shaft of the cylinder A coil that moves in a direction, a piston that is connected to the coil and moves in the cylinder in the axial direction, a resonance spring that is connected to the piston, a displacement detector that is connected in the axial direction of the piston, A converter circuit for converting to electric power, an inverter circuit for converting a direct current to an alternating current by switching a transistor or the like and applying a voltage to the coil, and a top dead center and a bottom dead center of the piston from a piston position signal from the displacement detector Top dead center position calculating means for calculating a position, and a top dead center position comparison signal that is a difference between the top dead center position and a preset top dead center reference value A position comparison means; a current detector for detecting a current flowing through the coil; a current value calculation means for calculating an average current value from a current waveform signal from the current detector; Current value comparison means for comparing the current value and current current value and outputting a current value comparison signal, and the top dead center reference value is larger than the top dead center position by the top dead center position comparison signal The output voltage of the inverter circuit is increased, and if the reference value of the top dead center is smaller than the top dead center position, the output voltage is decreased, and the output voltage of the inverter circuit is calculated by the current value comparison signal. By providing the inverter control means C for controlling the current value to be minimized by increasing or decreasing the time ratio between the wave period and the negative half-wave period by a reference ratio, the vibration type compression is always performed. The time ratio between the positive half wave and the negative half wave of the output voltage can be controlled such that the input power of the piston is minimized, the time ratio between the compression period and the suction period of the piston, The vibration type compressor can be made more efficient than when the time ratio between the positive half wave and the negative half wave of the coil current as the driving source is accurately matched.
[0095]
In addition, by creating a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control to change the equivalent voltage of the pulse width into a sine wave, the efficiency can be further improved compared to the rectangular wave drive of the operation cycle. Can be planned.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vibration type compressor according to a first embodiment of the present invention.
FIG. 2 is an electric circuit diagram according to the embodiment.
FIG. 3 is an operation waveform diagram of the inverter circuit in the same embodiment;
FIG. 4 is an operation flowchart according to the embodiment.
FIG. 5 is an operation timing chart according to the embodiment.
FIG. 6 is an electric circuit diagram according to a second embodiment of the present invention.
FIG. 7 is an operation flowchart according to the embodiment.
FIG. 8 is an operation timing chart according to the embodiment.
FIG. 9 is an electric circuit diagram according to a third embodiment of the present invention.
FIG. 10 is a flowchart of the operation in the embodiment.
FIG. 11 is a sectional view of a conventional vibration type compressor.
FIG. 12 is a displacement waveform diagram of a piston of a conventional vibration type compressor.
FIG. 13 is a drive circuit diagram of a conventional vibration type compressor.
[Explanation of symbols]
1 coil
26 Vibrating compressor
27 cylinders
28 Magnet
30 piston
31 Suction valve
32 Discharge valve
36 Resonant spring
37 Displacement detector
39 Converter circuit
41 Inverter circuit
45 Top dead center bottom dead center position calculation means
46 Top dead center position comparison means
47 Inverter control means A
48 Piston displacement time ratio calculation means
50 Current detector
52 Current waveform time ratio calculation means
53 Time ratio comparison means
54 Inverter control means B
56 Current value calculation means
57 Current value comparison means
58 Inverter control means C

Claims (3)

A cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged annularly around the cylinder, and disposed opposite to the magnet and acting on the magnet in the axial direction of the cylinder A moving coil; a piston connected to the coil and moving in the cylinder in the axial direction; a resonance spring connected to the piston; a displacement detector connected to the piston in the axial direction; and AC power to DC power. A converter circuit for conversion, an inverter circuit for converting a direct current to an alternating current by switching a transistor and the like, and applying a voltage to the coil; and a piston top dead center and a bottom dead center position from a piston position signal from the displacement detector A top dead center position that outputs a top dead center position comparison signal that is a difference between the top dead center position and a preset top dead center reference value. A comparing means; a piston displacement time ratio calculating means for calculating a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position; and the top dead center position comparison signal. When the top dead center reference value is larger than the top dead center position, the output voltage of the inverter circuit is increased, and when the top dead center reference value is smaller than the top dead center position, the output voltage is decreased. And an inverter control means A configured to control the time ratio between the compression period and the suction period and the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit to be equal to each other. Machine. A cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged annularly around the cylinder, and disposed opposite to the magnet and acting on the magnet in the axial direction of the cylinder A moving coil; a piston connected to the coil and moving in the cylinder in the axial direction; a resonance spring connected to the piston; a displacement detector connected to the piston in the axial direction; and AC power to DC power. A converter circuit for conversion, an inverter circuit for converting a direct current to an alternating current by switching a transistor and the like, and applying a voltage to the coil; and a piston top dead center and a bottom dead center position from a piston position signal from the displacement detector A top dead center position that outputs a top dead center position comparison signal that is a difference between the top dead center position and a top dead center reference value set in advance. Comparing means, piston displacement time ratio calculating means for calculating a time ratio between a compression period and a suction period in one cycle of piston displacement from the top dead center position and bottom dead center position, and detecting a current flowing through the coil A current waveform detector, a current waveform time ratio calculating means for calculating a time ratio between a positive half wave period and a negative half wave period of the coil current from a current waveform signal from the current detector, and a compression period of the piston displacement A time ratio comparison means for outputting a time ratio comparison signal that is a difference between a time ratio of the half current period corresponding to the compression period of the coil current, and the top dead center by the top dead center position comparison signal When the top dead center reference value is larger than the position, the output voltage of the inverter circuit is increased, and when the top dead center reference value is smaller than the top dead center position, the output voltage is decreased and the time If the time ratio of the compression period of the piston displacement is greater than the time ratio of the half-wave period corresponding to the compression period of the coil current according to the rate comparison signal, the half-wave corresponding to the compression period of the output voltage of the inverter circuit When the time ratio of the period is increased by a reference ratio, and the time ratio of the compression period of the piston displacement is smaller than the time ratio of the half-wave period corresponding to the compression period of the coil current, the output voltage of the inverter circuit is compressed A vibration type compressor comprising inverter control means B for controlling the time ratio of the half-wave period corresponding to the period to be reduced by the reference ratio. A cylindrical cylinder provided with a suction valve and a discharge valve, a magnet arranged annularly around the cylinder, and disposed opposite to the magnet and acting on the magnet in the axial direction of the cylinder A moving coil; a piston connected to the coil and moving in the cylinder in the axial direction; a resonance spring connected to the piston; a displacement detector connected to the piston in the axial direction; and AC power to DC power. A converter circuit for conversion, an inverter circuit for converting a direct current to an alternating current by switching a transistor and the like, and applying a voltage to the coil; A top dead center position that outputs a top dead center position comparison signal that is a difference between the top dead center position and a preset top dead center reference value. Comparing means, a current detector for detecting a current flowing through the coil, a current value calculating means for calculating an average current value from a current waveform signal from the current detector, and storing the current value and storing the current value Current value comparison means for comparing the current value with the current value of this time and outputting a current value comparison signal, and when the top dead center reference value is greater than the top dead center position by the top dead center position comparison signal The output voltage of the inverter circuit is increased. When the top dead center reference value is smaller than the top dead center position, the output voltage is decreased, and a positive half wave of the output voltage of the inverter circuit is determined by the current value comparison signal. A vibration type compressor comprising inverter control means C for controlling the current value to be minimized by increasing or decreasing the time ratio between the period and the negative half-wave period by a reference comparison.

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