JPH09324764A - Oscillatory type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly conform both time ratios to each other by providing an inverter control means controlling so as to equalize the time ratio of a compression period to a suction period to the time ratio of positive half-wave to negative half-wave of output voltage of an inverter circuit. SOLUTION: A top-dead-center/bottom-dead-center position computing means 45 computes the top dead center position and the bottom dead center position of a piston from the piston position signal from a displacement detector 37. Next, a piston displacement time ratio computing means 48 computes the time ratio of a compression period to a suction period in one cycle of the piston from the top dead center position and the bottom dead center position. Hereafter, an inverter control means 47 PWM-controls an inverter circuit 41, so as to equalize the time ratio of positive half-wave to negative half-wave of output voltage of an inverter circuit 41 to the time ratio of the compression period to the suction period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vibration type compressor such as a refrigerator.

[0002]

2. Description of the Related Art A vibration type compressor is used in a refrigerator or the like because of its simple structure, small size and light weight, high power factor, and low power consumption.

FIG. 11 is a sectional view of a general linear motor used for a vibration type compressor. 1 is a coil, 2 is a magnet, 3 is an outer iron core, 4 is an inner iron core, and 5 is an annular magnetic circuit. In a 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.

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, so that when the position where the AC voltage is not applied (hereinafter referred to as the neutral position) is used as a reference, the suction stroke is more than the compression stroke. It depends on the big thing.

FIG. 12 shows a displacement waveform of the piston.
In FIG. 12, the positive direction is the compression direction and the negative direction is the suction direction. Further, point a is the point where the amplitude in the compression direction is maximum (hereinafter referred to as top dead center), and the coil 1 in FIG.
Corresponds to the state of (a). Point b is the point where the amplitude in the suction direction is maximum (hereinafter referred to as bottom dead center), and the coil 1 is (b).
It corresponds to the state of.

If such a mechanical vibration system that vibrates asymmetrically is driven by a symmetrical current, the efficiency will deteriorate. Therefore, as a vibration type compressor with improved efficiency, control is performed so that the time ratio of the compression period and the suction period in one cycle of the piston displacement and the time ratio of the positive half wave and the negative half wave of the current are matched. For example, there is one disclosed in Japanese Patent Publication No. 63-8315.

A drive circuit for a conventional vibration type compressor will be described below with reference to FIG. In FIG. 13, reference numeral 1 is a coil, and 6, 7, 8, and 9 are main switching elements, and transistors 6 and 8 and 7 and 9 that are bridge-connected to each other are alternately turned on and off in pairs. Represent each one. Reference numerals 10 and 11 respectively supply the currents to the bases of the transistors 6 and 8 and 7 and 9, and reference numerals 12 and 13 control the collector currents of the transistors 21 and 20, that is, the base currents of the transistors 10 and 11, respectively. It is resistance. 14 and 15 are the transistor 7
And the resistors controlling the base currents of 8, 16, 17, 1
Reference numerals 8 and 19 are diodes which prevent the reverse connection of the DC power supply and form a discharging circuit of the capacitor 23 as described later. 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.

Reference numeral 22 is a variable resistor for controlling a charging / discharging current of a capacitor 23, which will be described later, 23 is a capacitor connected in parallel with the coil 1 through the detection switch elements 20 and 21, and 24 and 25 are Each represents a diode, and each represents a charge path for the capacitor 23. The detection switches 20, 21, the capacitor 23, the resistor 22, and the diodes 24, 25 constitute detection means.

The operation of this conventional vibration type compressor will be described. When 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 indicated by the solid line in the figure.

As the charging voltage of the capacitor 23 approaches the voltage of the terminals A and B, the transistor 21
The collector current of the device becomes smaller, and the main switching devices 6 and 8 move from the saturation region to the active region.

As a result, the voltage between the terminals A and B drops and the capacitor 23 starts discharging. Therefore, the transistor 21 is rapidly turned off, so that the main switching elements 6 and 8 are turned off, the main switching elements 7 and 9 are turned on, and a current flows in the coil in the direction indicated by the broken line.

By repeating the above-described self-excited transmission operation, the AC rectangular wave voltage of the operating frequency is supplied to the coil 1.

[0013]

However, in the above-mentioned conventional configuration, as the piston approaches the top dead center or the bottom dead center, the coil current, that is, the collector current (I _c ).
Becomes larger, and the main switching element is I _C ≧ I _B
Utilizing the fact that when x x _FE comes into the active region, the time ratio between the positive half wave and the negative half wave of the AC rectangular wave voltage at the operating frequency is matched with the time ratio between the compression period and the suction period of the piston displacement. As a result, I _C fluctuates due to load fluctuations of the vibration type compressor, and h due to ambient temperature fluctuations.
_{If the FE} fluctuates, the difference in the time ratio between the piston displacement and the AC rectangular wave voltage fluctuates, and the efficiency of the vibration type compressor decreases. Further, there is a problem in that the efficiency is reduced as compared with the sine wave drive because the rectangular wave voltage drive of the operating frequency is performed.

The present invention solves the conventional problems, and an object thereof is to improve the efficiency of a vibration type compressor.

[0015]

In order to solve this problem, the present invention provides a displacement detector connected in the axial direction of a piston,
An inverter circuit that converts direct current to alternating current by applying a voltage to the coil by switching a transistor or the like, and a top dead center below which calculates the top dead center and bottom dead center position of the piston from the piston position signal from the displacement detector. Dead center position calculating 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 the compression period. The inverter control means A is configured to control so that the time ratio of the suction period and the time ratio of the positive half wave and the negative half wave of the output voltage of the inverter circuit become equal.

As a result, high efficiency of the vibration type compressor is realized.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention described in the claims of the present invention
A cylinder of a cylindrical body provided with an intake valve and a discharge valve, a magnet arranged annularly around the cylinder, and a magnet that is installed so as to face the magnet and acts on the magnet in the axial direction of the cylinder. A coil that moves, 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, and AC power to DC power. A converter circuit for converting, an inverter circuit for converting a direct current into an alternating current by switching a transistor or the like to apply a voltage to the coil, and a top dead center and a bottom dead center position of the piston from the piston position signal from the displacement detector. Top dead center bottom dead center position calculating means for calculating, and a top dead center position for outputting 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 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 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. At the same time, the vibration type compression is constituted by the inverter control means A for controlling so that 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 become equal. The top dead center bottom dead center position calculating means calculates the top dead center position and the bottom dead center position of the piston from the piston position signal from the displacement detector, and calculates the piston displacement time ratio. hand There calculates the time ratio between the intake period and the compression period of one cycle of the piston from the top dead center position and a bottom dead center position.

Then, the inverter control means A drives 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 becomes equal to the time ratio between the compression period and the suction period. PWM (Pulse Wi
dth Modulation) is controlled.

According to a second aspect of the present invention, a cylindrical cylinder provided with an intake valve and a discharge valve, a magnet annularly arranged around the cylinder, and a magnet arranged to face the magnet are provided. A coil that acts on the magnet and 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 an axial direction of the piston. Displacement detector, a converter circuit for directly converting AC power into electric power, an inverter circuit for converting DC to AC by applying a voltage to the coil by switching a transistor or the like, 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 positions of the piston, and the difference between the top dead center position and a preset top dead center reference value. Top dead center position comparing means for outputting a point position comparison signal, and a piston displacement time ratio 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 calculating means, a current detector for detecting a current flowing through the coil, and a current waveform time 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 ratio calculation means, a time ratio comparison means for outputting a time ratio comparison signal which is a difference between a time ratio of a compression period of the piston displacement and a time ratio of a half-wave period corresponding to the compression period of the coil current; When 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 the top dead center reference value is smaller than the top dead center position. Out of case When 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 by the time ratio comparison signal while decreasing the voltage of the output voltage of the inverter circuit When the time ratio of the half-wave period corresponding to the compression period is increased by the 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. A vibration type compressor constituted by an inverter control means B for controlling the time ratio of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit by a reference ratio to reduce the current waveform. Time ratio calculation means 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 from the current detector, The ton displacement time ratio calculating means calculates the time ratio between the compression period and the suction period in one cycle of the displacement of the piston from the top dead center position and the bottom dead center position.

Next, the time ratio comparison means outputs a time ratio comparison signal which 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. To do.

When 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, the inverter control means B receives the time ratio comparison signal. The time ratio of the half-wave period corresponding to the compression period of the output voltage of the inverter circuit is increased by the reference ratio, and the time ratio of the compression period of the piston displacement is the half-wave period corresponding to the compression period of the coil current. When the time ratio is smaller than the time ratio, 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.

According to a third aspect of the present invention, a cylindrical cylinder provided with an intake valve and a discharge valve, a magnet annularly arranged around the cylinder, and a magnet arranged to face the magnet are provided. A coil that acts on the magnet and 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 an axial direction of the piston. Displacement detector, a converter circuit for converting AC power to DC power, an inverter circuit for converting DC to AC by applying a voltage to the coil by switching a transistor and the like, 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 positions of the piston, and the difference between the top dead center position and a preset top dead center reference value. Top dead center position comparison means for outputting a point position comparison signal, a current detector for detecting a current flowing through the coil, and current value calculation means for calculating an average current value from a current waveform signal from the current detector. , A current value comparison means for storing the current value and comparing the current value stored last time with the current value of this time, and outputting a current value comparison signal; and the top dead center position comparison signal from the top dead center position. The output voltage of the inverter circuit is increased when the top dead center reference value is larger, and the output voltage is decreased when the top dead center reference value is smaller than the top dead center position, and the current value comparison signal Inverter control means C for increasing or decreasing 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 so as to minimize the current value. In the vibration type compressor, the current value calculating means calculates an average current value from the current waveform signal from the current detector, and the current value comparing means stores the current value, The current value stored last time is compared with the current value this time, and a current value comparison signal is output.

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 according to the current value comparison signal to increase or decrease the current value. Has the effect of performing PWM control so that is minimized.

A first embodiment of a vibration type compressor according to the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a sectional view of a vibration type compressor according to the first embodiment of the present invention, FIG. 2 is an electric circuit diagram of the same embodiment, and FIG. 3 is an operation waveform diagram of an inverter circuit of the same embodiment. 4, FIG. 4 is an operation flowchart in the same embodiment, and FIG. 5 is an operation time chart in the same embodiment.

In FIG. 1, a cylindrical cylinder 27 is provided in the center of a vibration type compressor 26, and a permanent magnet 28 is annularly arranged around the cylinder 27.
An annular coil 1 is provided between the permanent magnet 2 and the cylinder 27.
Is installed and acts on the permanent magnet 2 to move in the axial direction of the cylinder 27.

A compression piston 1 is provided in the cylinder 27.
4 is housed, forms a compression chamber 33 having an intake valve 31 and a discharge valve 32, is connected to the coil 1, and moves 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 including a differential transformer connected in the axial direction of the piston 14.

A magnetic field is formed by the permanent magnet 2 between the permanent magnet 2 and the cylinder 27, and when an alternating current is supplied to the coil 1 arranged between them, a supply alternating current is supplied to the coil 1. A thrust that oscillates according to the frequency of the electric current is applied to drive the piston 14 connected to the coil 1 in the axial direction. Next, the electric circuit shown in FIG. 2 will be described. A commercial AC power source 38 is connected to an AC input section of a converter circuit 39 that converts AC into DC. The converter circuit 39 includes 39a, 39
It is composed of four diodes b, 39c and 39d, and the connection point between the anode of the diode 39a and the cathode of 39d and the anode of the diode 39b and 3
The commercial AC power supply 38 is connected to each connection point of the cathodes of 9c. The cathode of the diode 39a and the cathode of the diode 39b are connected, and the anode of the diode 39c and the anode of 39d are connected.

A smoothing circuit 40 is composed of two electrolytic capacitors 40a and 40b. Further, the connection point between the diodes 39a and 39b and the positive electrode side of the electrolytic capacitor 40a are connected, the connection point between the diodes 39b and 39c and the negative electrode side of the electrolytic capacitor 40a are connected, and the connection point between the diodes 39c and 39d and the above The negative electrode side of the electrolytic capacitor 40b is connected.

The positive side of the electrolytic capacitor 40a is connected to the collector of the transistor TR1 and the cathode of the diode D1 in the inverter circuit 41, and the negative side of the electrolytic capacitor 40a is connected to the positive side of the electrolytic capacitor 40b. At the same time, it is connected to one side (A in the figure) of the coil 1 of the vibration type compressor 26. 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.

In the inverter circuit 41, the connection point between the emitter of the transistor TR1, the collector of the transistor TR2, the anode of the diode D1 and the diode D2 is the electrolytic capacitor of the coil 1 of the signal type compressor 26. It is connected to the side (not shown) which is not connected to 40a. Then, TR1 is driven by the PWM signal from the upper arm drive circuit 42 described later, and TR2 is driven by the PWM signal from the arm transistor 43 described later.

FIG. 3 shows an operation waveform diagram of the inverter circuit 41. 3A and 3B show the drive signal of TR1 and the drive signal of TR2, respectively, where TR1 is PW.
TR2 is in the OFF state during the half cycle in which it is turned on and off by the M signal, and vice versa during the following half cycle.

FIG. 3 (c) shows the output voltage of the inverter circuit 41, which is A of the coil 1 of the vibration type compressor 26,
Supplied between B. The solid lines in FIG. 3C are TR1 and TR2.
It is a PWM output that is amplified to a plurality of pulse trains of a carrier cycle in the output waveform of the operating cycle, and the equivalent voltage (illustrated by a broken line) of the pulse width is changed in a sine wave shape.

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 of the positive half wave and the negative half wave in one cycle of the output voltage. To change, the time ratio between the ON / OFF period by the PWM signal of TR1 and the ON / OFF period by the PWM signal of TR2 may be changed.

Reference numeral 37 is 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 a first A / D converter 44. Is converted into a digital signal via and is input to the top dead center bottom dead center position calculation means 45.

The top dead center bottom dead center position calculating means 45 calculates the top dead center position and bottom dead center of the piston 30. 46
Is a top dead center position comparison means, and 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 the inverter control means A47 described later. Reference numeral 48 is a piston displacement time ratio calculating means,
Displacement within one cycle of 0 The time ratio of the compression period from the bottom dead center position to the top dead center position and the suction period from the top dead center to the bottom dead center is output to the inverter control means A47. .

The inverter control means A47 is a PWM
Waveform generation means A49, the upper arm drive circuit 42,
The lower arm drive circuit 43 is provided, and the waveform generating means A49 presets the output voltage of the inverter circuit 41 according to the top dead center position comparison signal when the top dead center reference value is larger than the top dead center position. PW to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to increase by the reference voltage value and decrease by the reference voltage value when the top dead center reference value is smaller than the top dead center position.
The upper arm drive circuit 42 outputs the M waveform signal and makes the time ratio between the compression period and the suction period equal to the time ratio between the positive half wave and the negative half wave of the output voltage of the inverter circuit. And lower arm drive circuit 43
The PWM waveform signal is output to.

The operation of the vibration type compressor configured as described above will be described below with reference to the flowchart of FIG. 4 and the timing chart of FIG.

In step 1, the commercial AC power supply 22 is turned on. The electrolytic capacitor 40 is charged via the converter circuit 39 and supplies DC power to the inverter circuit 41. PWM signals are output from the upper arm drive circuit 42 and the lower arm drive circuit 43, and TR1 and TR2 of the inverter circuit 41 are alternately PWMed.
The signal is repeated during the half cycle in which it is turned on and off and the off state.

An output voltage obtained by converting direct current into alternating current is supplied from the inverter circuit 41 to the coil 1 of the vibration type compressor 26, and the vibration type compressor 26 starts its operation.
The piston 30 connected to the coil 1 vibrates in the axial direction of the cylinder 27 according to the frequency of the output voltage, and the refrigerant is compressed in the compression chamber 33.

The PW immediately after the commercial AC power source 22 is turned on.
M signal operating frequency, pulse width, the inverter circuit 4
The time ratio of the positive half wave and the negative half wave of the output voltage of 1 is a predetermined value.

In step 2, the displacement detector 37
The analog position signal of the piston 30 from
It is converted into a digital signal through the D converter 44 and input to the top dead center bottom dead center position calculating means 45. This signal indicates the upper end position of the piston 30 facing the compression chamber 33, which is designated as A. Immediately after the power is turned on, A is set to 0.

Next, at step 3, the top dead center position B which is the maximum value of the upper end position of the piston 30 in the top dead center bottom dead center position calculating means 45 as shown in cycle 1a of FIG.
Is calculated.

In step 4 and step 5, the top dead center position comparison signal from the top dead center position comparing means 46 and the top dead center reference value C which is a preset value are used to generate the top dead center position comparison signal. When the point reference value 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 inverter output voltage V by the reference voltage E as shown in cycle 2b of FIG. A PWM waveform is output to the upper arm drive circuit 42 and the lower arm drive circuit 43.

When the top dead center reference value C and the top dead center position B are the same, the routine proceeds to step 7, where the inverter output voltage V holds the current voltage as shown in cycle 4b of FIG.

Further, the top dead center reference value C is higher than the top dead center position B.
If it is smaller, the process proceeds to step 8, and the PWM waveform generation means A49 outputs the PWM waveform to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to reduce the inverter output voltage V by the reference voltage D (not shown). Output.

Immediately after the power is turned on, steps 2, 3, 4, 6 are performed.
Is repeatedly repeated to gradually increase the inverter output voltage. As the inverter output voltage increases, the stroke of the piston 30 increases and the cycle 3
As shown in a, when the top dead center position B of the piston 30 becomes equal to the top dead center reference value C, the routine proceeds to step 7, the inverter output voltage is held at the same voltage, and the routine proceeds to step 9.

In step 9, the piston position / time ratio calculating means 48 causes the bottom dead center position D within the displacement of the piston 30 in one cycle as shown in the cycle 4a of FIG.
The time ratio α for one cycle of the compression period from to the top dead center position B is calculated.

Next, proceeding to step 10, the PWM waveform generating means A causes the PWM waveform generating means A to output the time ratio α: (1−α) between the compression period and the suction period and the output of the inverter circuit 47, as shown in cycle 5b of FIG. The upper arm drive circuit 4 is arranged so that the time ratios of the positive half-wave and the negative half-wave of the voltage become equal.
2 and the PWM waveform signal is output to the lower arm drive circuit.

After performing step 6, step 8 or step 9, the process returns to step 2 and a series of operations is repeated.

As described above, the vibration type compressor of this embodiment is
The top dead center bottom dead center position calculating means 45 calculates the top dead center position and the bottom dead center position of the piston 30 from the piston position signal from the displacement detector 37, and the piston displacement time ratio calculating means 48 is calculated. From the top dead center position and the bottom dead center position, the time ratio of the compression period and the suction period in one cycle of the piston 30 is calculated, and the inverter control means A47
The inverter circuit 41 is PWM-controlled so that the time ratio between the positive half-wave and the negative half-wave of the output voltage of the inverter circuit 41 becomes equal to the time ratio between the compression period and the suction period.

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. It is possible to improve the efficiency of the vibration type compressor 26.

Further, by making 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 in a sine wave shape, compared with the rectangular wave drive of the operation cycle. It is possible to improve efficiency.

Next, a second embodiment of the present invention will be described with reference to the drawings. The same components as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 6 is an electric circuit diagram in the second embodiment of the present invention, and FIG. 7 is an operation flowchart in the same embodiment.

In FIG. 6, 50 is a current detector,
It is inserted between the coil 1 and the intersection of the electrolytic capacitor 40a and the electrolytic capacitor 40b, and detects a current flowing in the coil 1 (the direction of the arrow in the drawing is positive).

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 the current waveform time ratio calculation means 52 is provided.
Is input to The current waveform time ratio calculation means 52,
The time ratio between the positive half-wave period and the negative half-wave period of the coil current is calculated from the current waveform signal.

Reference numeral 53 is a time ratio comparison means, which will be described later with reference to a time ratio comparison signal which is the 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 the inverter control means B54.

The inverter control means B54 has a PWM
Waveform generating means B55, the upper arm drive circuit 42,
The lower arm drive circuit 43 is provided, and the waveform generation means B55 presets the output voltage of the inverter circuit 41 according to the top dead center position comparison signal when the top dead center reference value is larger than the top dead center position. PW to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to increase by the reference voltage value and decrease by the reference voltage value when the top dead center reference value is smaller than the top dead center position.
When the M waveform signal is output and the time ratio of the compression period of the piston displacement is greater than the time ratio of the positive half-wave period corresponding to the compression period of the coil current by the time ratio comparison signal, the inverter circuit 41. The time ratio of the positive 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 positive half-wave period corresponding to the compression period of the coil current. If the time ratio is smaller than the time ratio, the PWM waveforms are applied to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to reduce the time ratio of the positive half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 by the reference ratio. Output a signal.

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.

In step 101, the commercial AC power source 38 is turned on. Next, in step 102, the same process as the process from step 2 to step 8 (hereinafter referred to as top dead center control) described in the timing chart of the first embodiment in FIG. 4 is performed, and the cycle 11a in 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,
Go to step 103.

In step 103, the piston position / time ratio calculating means 48 moves from the bottom dead center position D to the top dead center position B of the displacement of the piston 30 in one cycle, as shown in the cycle 11a of FIG. The time ratio α for one cycle of the compression period is calculated.

Next, in step 104, the current waveform calculating means 52 determines the time ratio of the positive half-wave period of one cycle of the coil current from the current waveform signal to one cycle as shown in cycle 11C of FIG. Calculate γ.

Next, at steps 105 and 106, the time ratio comparison means 53 calculates the time ratio α of the compression period of the piston displacement and the time ratio γ of the positive half-wave period corresponding to the compression period of the coil current. When the time ratio α of the compression period is smaller than the time ratio γ of the positive half wave of the coil current by comparing and outputting the time ratio comparison signal, the process proceeds to step 107, and cycle 1 of FIG.
2b, the upper arm drive circuit 42 and the lower arm drive circuit 43 are configured to reduce the time ratio β of the positive half-wave period corresponding to the compression period of the output voltage of the inverter circuit 41 by the reference ratio e. Output a PWM waveform signal.

When 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, step 1
08, the time ratio β of the positive half-wave period of the output voltage holds the current time ratio as shown in cycle 14B of FIG.

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 used as a reference. Increase by the ratio e (not shown)
Thus, the PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43.

After performing step 107, step 108 or step 109, the process returns to step 102 to repeat a series of operations.

As described above, the vibration type compressor of this embodiment is
The time ratio comparison means 53 calculates a time ratio comparison signal which is the 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, and calculates the time ratio comparison signal. The control means B54, when the time ratio of the compression period of the piston displacement is greater than the time ratio of the positive half-wave period corresponding to the compression period of the coil current according to the time ratio comparison signal, the inverter circuit 4
The time ratio of the positive half wave period corresponding to the compression period of the output voltage of 1 is increased by the reference ratio, and the time ratio of the compression period of the piston displacement is larger than that of the positive half wave corresponding to the compression period of the coil current. When the time ratio is smaller than the time ratio of the period, 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 41 is reduced by the reference ratio.

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 coil current, which is the direct drive source of the piston 30, are accurately determined. The vibration type compressor 26 has higher efficiency 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. Can be realized.

Further, by making 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 in a sinusoidal manner, compared with the rectangular wave drive of the operation cycle. It is possible to improve efficiency. The time ratio between the compression period and the suction period of 0 and the time ratio between the positive half wave and the negative half wave of the coil current, which is the direct drive source of the piston 30, can be accurately matched, and the piston 30 It is possible to further improve the efficiency of the vibration type compressor 26 by combining the time ratio between the compression period and the suction period with the time ratio between the positive half wave and the negative half wave of the output voltage.

Further, by making a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control for changing the equivalent voltage of the pulse width in a sine wave shape, as compared with the rectangular wave drive of the operation cycle. It is possible to improve efficiency.

Next, a third embodiment of the present invention will be described with reference to the drawings. The same components as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 9 is an electric circuit diagram in the third embodiment of the invention. In FIG. 9, reference numeral 56 is a current value calculation means, which calculates an average current value from the current waveform signal. Reference numeral 57 is a current value comparison means, which stores the current value, compares the current value stored previously and the current value of this time, and outputs a current value comparison signal.

Reference numeral 58 is an inverter control means C, which is a PW.
M waveform generation means C59, the upper arm drive circuit 4
2. The lower arm drive circuit 43 is provided, and the waveform generation means C59 outputs the output voltage of the inverter circuit 41 when the top dead center reference value is larger than the top dead center position according to the top dead center position comparison signal. Is increased by a preset reference voltage value, and is decreased by the reference voltage value when the top dead center reference value is smaller than the top dead center position, the upper arm drive circuit 42 and the lower arm drive circuit 43.
And a PWM waveform signal is output to the current value comparison signal and the current value comparison signal is used to increase or decrease the time ratio between the positive half-wave period and the negative half-wave period of the output voltage of the inverter circuit 41 by a reference ratio. The upper arm drive circuit 42 and the lower arm drive circuit 43 are minimized.
The PWM waveform signal is output to.

The operation of the vibration type compressor configured as described above will be described below with reference to the flowchart of FIG.

In step 201, the commercial AC power source 38 is turned on. Next, at step 202, the same process as the process from step 2 to step 8 (hereinafter referred to as top dead center control) described in the timing chart of the first embodiment in FIG. 4 is performed, and the top dead center of the piston 30 is performed. 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 routine proceeds to step 203.

In step 203, the current value calculating means 5
6 calculates an average current value i from the current waveform signal,
In step 204, the current value comparison means 57 stores the current value i as the minimum current value _imin .

Next, in step 205, the upper arm drive circuit 42 and the lower arm drive circuit 42 and the lower arm drive circuit 42 are controlled 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.

Next, in step 206, the current value calculating means 56 calculates the average current value i from the current waveform signal, and in step 207 the current value comparing means 57 calculates the current value i and the minimum current value i. i _min is compared, and the current value i
If is smaller than, the process proceeds to step 208 and the current value i is stored as the minimum current value _imin .

Next, in step 209, the upper arm drive circuit 42 and the lower arm drive circuit 42 and the lower arm drive circuit 42 are arranged to reduce the time ratio β of the positive 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 the arm drive circuit 43.

Next, in step 210, the current value calculating means 56 calculates the average current value i from the current waveform signal, and in step 211 the current value comparing means 57 calculates the current value i and the minimum current value i. i _min is compared, and the current value i
If is smaller than, the process proceeds to step 208, the current value i is stored as the minimum current value i _min , and step 20 is performed again.
9, until the current value i becomes larger than the minimum current value i _min , 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 decreased by the reference ratio amount e. Then, the process of outputting the PWM waveform signal to the upper arm drive circuit 42 and the lower arm drive circuit 43 is continued.

In step 211, if the current value i is larger than the minimum current value i _min , the process proceeds to step 213, where 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 used as a reference. A PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to increase the ratio e, and the current value i is set to the minimum current value, and the process returns to step 202.

On the other hand, in step 207, the current value comparison means 57 compares the current value i with the minimum current value _imin , and if the current value i is larger, the process proceeds to step 214 and the inverter circuit 41 is operated. A PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so that the time ratio β of the positive half-wave period corresponding to the compression period of the output voltage is increased by the reference ratio e.

Next, in step 215, the current value calculating means 56 calculates an average current value i from the current waveform signal, and in step 216 the current value comparing means 57 calculates the current value i and the minimum current value i. _min is compared, and the current value i
Is smaller, the process proceeds to step 217, the current value i is stored as the minimum value i _min , and the process returns to step 214 and the output of the inverter circuit 41 is output until the current value i becomes larger than the minimum current value i _min. The process of outputting the PWM waveform signal to the arm drive circuit 42 and the lower arm drive circuit 43 is continued so as to increase the time ratio β of the positive half-wave period corresponding to the voltage compression period by the reference ratio e.

[0085] In step 216, when the current value i is greater than the minimum value i _min, the process proceeds to step 218, reference ratio the time ratio β of the positive half-wave period that corresponds to the compression period of the output voltage of the inverter circuit 41 A PWM waveform signal is output to the upper arm drive circuit 42 and the lower arm drive circuit 43 so as to reduce the current value i.
Is set to the minimum current value and the process returns to step 202.

As described above, the vibration type compressor of this embodiment is
The current value calculating means 56 calculates an average current value from the current waveform signal from the current detector 50, and the current value comparing means 57 stores the current value, and the current value stored previously is stored. The current value is compared and the current value comparison signal is output.

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 the reference ratio by the current value comparison signal to increase or decrease the current value. Has the effect of performing PWM control so that is minimized.

Therefore, the time ratio of 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 of the piston 30 is Higher efficiency of the vibration type compressor 26 than accurate matching of the time ratio with the suction period and the time ratio with the positive half wave and the negative half wave of the coil current that is the direct drive source of the piston 30. Can be realized.

Further, by making 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 in a sine wave shape, compared with the rectangular wave drive of the operation cycle. It is possible to improve efficiency.

[0090]

As described above, according to the present invention, a cylindrical cylinder provided with an intake valve and a discharge valve, a magnet annularly arranged around the cylinder, and the magnet are installed so as to face the magnet. A coil that acts on the magnet and 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 an axial direction of the piston. Displacement detector connected, converter circuit for converting AC power to DC power, inverter circuit for converting DC to AC by switching transistors etc. and applying voltage to the coil, piston position from the displacement detector Top dead center bottom dead center position calculating means for calculating the top dead center and bottom dead center positions of the piston from the signal, and the difference between the top dead center position and a preset top dead center reference value. Top dead center position comparing means for outputting a point position comparison signal, and a piston displacement time ratio 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 larger than the top dead center position by the calculating means and the top dead center position comparison signal, the output voltage of the inverter circuit is increased and the top dead center reference is calculated from the top dead center position. When the value is smaller, the output voltage is decreased and the time ratio between the compression period and the suction period is controlled 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. By providing the inverter control means A, 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 can be accurately matched. , It is possible to achieve high efficiency of the vibrating compressor.

Further, by making many 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 in a sine wave shape, compared to the rectangular wave drive of the operation cycle. It is possible to improve efficiency.

Further, a cylindrical cylinder provided with an intake valve and a discharge valve, a magnet arranged in an annular shape around the cylinder, and a magnet which is installed so as to face the magnet and acts 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, a displacement detector that is connected in the axial direction of the piston, and an alternating current A converter circuit for converting electric power into DC power, an inverter circuit for converting DC into AC by applying a voltage to the coil by switching a transistor or the like, and a piston top dead center from a piston position signal from the displacement detector. Top dead center bottom dead center position calculating means for calculating the bottom dead center position, and 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. Force applying top dead center position comparing means, piston displacement time ratio calculating means for calculating the time ratio between the compression period and the 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 the positive half-wave period and the negative half-wave period of the coil current from the current waveform signal from the current detector, A time ratio comparison means for outputting a time ratio comparison signal which is a difference between a time ratio of a 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 position comparison. The signal increases the output voltage of the inverter circuit when the top dead center reference value is larger than the top dead center position, and decreases the output voltage when the top dead center reference value is smaller than the top dead center position. Let In both cases, when the time ratio of the compression period of the piston displacement is greater than the time ratio of the corresponding half-wave period of the compression period of the coil current according to the time ratio comparison signal, it corresponds to the compression period of the output voltage of the inverter circuit. If the time ratio of the half period is increased by the 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 of the inverter circuit By providing the inverter control means B for controlling the time ratio of the half-wave period corresponding to the voltage compression period to be reduced by the reference ratio, the time ratio between the compression period and the suction period of the piston and the piston The time ratio between the positive half-wave and the negative half-wave of the coil current, which is a direct drive source, can be accurately matched, and the compression period of the piston and the suction It is possible to further improve the efficiency of the vibration type compressor by comparing the time ratio with the on period and the time ratio with the positive half wave and the negative half wave of the output voltage.

Further, by making a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control for changing the equivalent voltage of the pulse width in a sine wave shape, compared with the rectangular wave drive of the operation cycle. It is possible to improve efficiency.

Further, a cylindrical cylinder provided with an intake valve and a discharge valve, a magnet annularly arranged around the cylinder, and a magnet arranged to face 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, a displacement detector that is connected in the axial direction of the piston, and an alternating current A converter circuit for converting electric power into DC power, an inverter circuit for converting DC into AC by applying a voltage to the coil by switching a transistor or the like, and a piston top dead center from a piston position signal from the displacement detector. Top dead center bottom dead center position calculating means for calculating the bottom dead center position, and 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. Top dead center position comparing means for applying a force, 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 value A current value comparison means for comparing the current value stored in the previous time with the current value stored this time and outputting a current value comparison signal, and the top dead center reference from the top dead center position by the top dead center position comparison signal. When the value is larger, 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 current value comparison signal causes the inverter circuit to By providing the inverter control means C for increasing or decreasing the time ratio between the positive half-wave period and the negative half-wave period of the output voltage by the reference ratio so as to minimize the current value, 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 becomes the minimum, and the time ratio between the compression period and the suction period of the piston, and It is possible to further improve the efficiency of the vibration type compressor as compared with the case where the time ratio between the positive half wave and the negative half wave of the coil current, which is the direct drive source of the piston, is accurately matched.

Further, by making a large number of pulse trains of the carrier cycle in the output waveform of the operation cycle and performing PWM control for changing the equivalent voltage of the pulse width in a sine wave shape, compared to the rectangular wave drive of the operation cycle. It is possible to improve efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view of a vibration type compressor according to a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram in the same embodiment.

FIG. 3 is an operation waveform diagram of the inverter circuit in the same embodiment.

FIG. 4 is an operation flowchart in the same embodiment.

FIG. 5 is an operation timing chart in the embodiment.

FIG. 6 is an electric circuit diagram according to a second embodiment of the present invention.

FIG. 7 is an operation flowchart in the same embodiment.

FIG. 8 is an operation timing chart in the embodiment.

FIG. 9 is an electric circuit diagram according to a third embodiment of the present invention.

FIG. 10 is a flowchart of an operation in the same 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 Codes] 1 coil 26 vibration type compressor 27 cylinder 28 magnet 30 piston 31 suction valve 32 discharge valve 36 resonance spring 37 displacement detector 39 converter circuit 41 inverter circuit 45 top dead center bottom dead center position calculating means 46 top dead Point 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)

[Claims] 1. A cylinder of a cylindrical body provided with an intake valve and a discharge valve, a magnet annularly arranged around the cylinder, and a magnet which is installed so as to face the magnet and acts 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, a displacement detector that is connected in the axial direction of the piston, and an alternating current A converter circuit for converting electric power into DC power, an inverter circuit for converting DC into AC by applying a voltage to the coil by switching a transistor or the like, and a piston top dead center from a piston position signal from the displacement detector. Top dead center bottom dead center position calculating means for calculating the bottom dead center position, and output a top dead center position comparison signal which is the difference between the top dead center position and a preset top dead center reference value Top dead center position comparison means, piston displacement time ratio calculation means for calculating the time ratio between the compression period and the 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 larger than the top dead center position by the dead center position comparison signal, the output voltage of the inverter circuit is increased, and the top dead center reference value is smaller than the top dead center position. Inverter control means A for controlling the output voltage so that 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 become equal. Vibration type compressor configured. 2. A cylindrical cylinder provided with an intake valve and a discharge valve, a magnet annularly arranged at the top of the cylinder, and a magnet which is installed so as to face the magnet and acts 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, a displacement detector that is connected in the axial direction of the piston, and an alternating current A converter circuit for converting electric power into DC power, an inverter circuit for converting DC into AC by applying a voltage to the coil by switching a transistor or the like, and a piston top dead center from a piston position signal from the displacement detector. Top dead center bottom dead center position calculating means for calculating the bottom dead center position and 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 are output. Top dead center position comparing means, piston displacement time ratio calculating means for calculating the time ratio between the compression period and the suction period in one cycle of piston displacement from the top dead center position and the bottom dead center position, and the coil A current detector for detecting a current flowing through the current detector, 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 a compression period of 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 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. With When 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, it corresponds to the compression period of the output voltage of the inverter circuit. When the time ratio of the half-wave period is increased by the 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 of the inverter circuit Inverter control means B for controlling the time ratio of the half-wave period corresponding to the voltage compression period to be reduced by the reference ratio.
Vibration type compressor composed of and. 3. A cylindrical cylinder provided with an intake valve and a discharge valve, a magnet disposed annularly around the cylinder, and a magnet disposed to face 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, a displacement detector that is connected in the axial direction of the piston, and an alternating current A converter circuit for converting electric power into DC power, an inverter circuit for converting DC into AC by applying a voltage to the coil by switching a transistor or the like, and a piston top dead center from a piston position signal from the displacement detector. Top dead center bottom dead center position calculating means for calculating the bottom dead center position and 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 are output. Top dead center 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, and the current value stored The current value comparison means for comparing the current value stored previously with the current value of this time and outputting a current value comparison signal, and the top dead center reference value from the top dead center position by the top dead center position comparison signal. Is larger, 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 output of the inverter circuit is output by the current value comparison signal. A vibration type compressor constituted by an inverter control means C for controlling the time ratio of the positive half-wave period and the negative half-wave period of the voltage to increase or decrease by a reference comparison amount so as to minimize the current value.