JP2003065244A - Control driving device and control driving method of linear compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent collision between a piston and cylinder of a linear compressor with high responsiveness, and recover a disturbance vibrational energy, in a control driving device of linear compressor reduced in size, and having a high efficiency and high reliability. SOLUTION: This control driving device of the linear compressor comprises: a regeneration control part 31 which controls such that a current flowing in a linear motor 3 of the linear compressor 1 is the same in direction as an induced voltage; and a function control part 24 which performs approximately constant control of an applied voltage to the motor, the induced voltage generated in the motor, and a piston stroke. Accordingly, by means of a regenerative braking force, the collision between the piston and the cylinder of the linear compressor is prevented and the stroke is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for preventing collision of a linear compressor in which a piston in a cylinder is reciprocated by a linear motor, and a technology for controlling and driving the linear compressor during disturbance vibration.

[0002]

2. Description of the Related Art A general linear compressor and its driving method will be described. FIG. 16 is a vertical sectional view of a linear compressor in which a piston in a cylinder is reciprocated by a linear motor. The linear compressor 1 includes a cylinder portion 2 arranged along a predetermined axis, a motor portion 3, a piston 4 disposed in the cylinder portion 2 and slidably supported in the axial direction, and one end thereof. Is fixed to the back side of the piston 4, and a support spring (resonance leaf spring) 6 supported by the spring fixing portion 14 on the other end side of the piston rod 5.
With.

A cylinder inner peripheral wall 2a is provided in the cylinder portion 2.
A compression chamber 10 which is a closed space surrounded by the cylinder head 2b and the piston compression surface 4a is formed. The cylinder head 2b has a gas suction valve 1 for sucking low-pressure refrigerant gas from the refrigerant gas suction passage 11 into the compression chamber 10.
2 and a discharge valve 13 for discharging the high pressure refrigerant gas from the compression chamber 10 to the refrigerant gas discharge pipe. Each of these valves also plays a role of preventing backflow of the refrigerant.

A magnet 7 serving as a field pole is attached to the piston rod 5, and the magnet 7 and an armature core 8 arranged around the magnet 7 are provided.
The motor part 3 is formed from the armature winding 9. Then, by supplying an alternating current from a driving device (not shown) to the armature winding 9 of the motor unit 3, an electromagnetic force generated between the armature winding 9 and the magnet 7 and resonance of the support spring 6 are generated. The force causes the piston 4 to reciprocate along its axial direction, and in accordance with this, the refrigerant suction, compression, and discharge operations are repeated.

In the linear compressor 1 as described above, there is a risk that the tip of the piston collides with the cylinder head 2b due to its structure. The center position of the reciprocating motion is offset in the piston 4 during the compression operation due to the difference between the pressure in the compression chamber 10 and the back surface pressure of the piston 4. Therefore, the load condition changes,
When the force due to the pressure applied to the piston 4 increases or decreases as a result, the center position and stroke of the vibration of the piston 4 change, and the piston 4 and the cylinder head 2b may collide depending on the conditions. As a method for avoiding this, there is a method disclosed in Japanese Patent Application Laid-Open No. 11-324911. In the method disclosed in this publication, when the linear compressor is driven on the basis of the current command value, if the piston may collide with the cylinder, the current command value is reduced to prevent the collision. . When the risk of collision is more serious, the power supply to the compressor is stopped to avoid the collision.

Next, regarding the control of the linear compressor under the influence of disturbance vibration, there is almost no precedent in the present situation.
Japanese Patent No. 2000-
There is one as shown in Japanese Patent No. 78885. In the method disclosed in this publication, when the actuator portion is stopped by a disturbance, it is detected and the energization is stopped for protection. In this case, the disturbance is dealt with at the expense of the original function.

[0007]

However, in the collision protection disclosed in Japanese Patent Laid-Open No. 11-324911, the current flowing through the linear motor is only reduced or the energization is stopped. Since the electromagnetic braking force in the direction does not act, the motion will continue for a relatively long time determined by inertia, damping of the vibration system, etc. If the piston displacement suddenly increases, it may not be possible to avoid collision. .

In an environment where disturbance vibration acts, in the case of a linear compressor, the piston is supported by a spring, so that the disturbance vibration affects the displacement of the piston and the risk of frequent collisions. Occurs. Therefore, frequent reduction of the current may cause the compressor to have insufficient capacity or become unstable. Further, in the worst case, the compressor is stopped, and there is a possibility that the original function is completely lost.

Further, it has not been possible to effectively utilize the surplus kinetic energy of the piston at the time of preventing a collision and the energy of the disturbance vibration at the time of steady operation.

Further, since the displacement sensor is used to detect the piston displacement, there is a problem that the cost and size are increased.

The present invention is intended to solve the above-mentioned problems, and it is a high-response and efficient collision prevention technique for a linear compressor, and a linear compressor that is stable and highly efficient even during disturbance vibrations, and is also capable of regenerating electric power. It is an object of the present invention to provide the control and drive technology of (3) with a relatively inexpensive structure.

[0012]

In order to solve the above problems, the control drive device for a linear compressor of the present invention has the following configuration.

(1) The control drive device is a linear system including a cylinder supported in a closed container, a piston movably supported in the cylinder by a spring member, and a linear motor for applying thrust to the piston in a movable direction. A device that controls and drives a compressor, a drive device that supplies alternating current power to a linear motor to reciprocate a piston, and a capacity control unit that controls the linear motor so that the capacity of the linear compressor has a desired value. And a collision prevention means for preventing the piston and the cylinder from colliding with each other. The collision prevention means is provided with a regenerative control unit that performs a predetermined control so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the linear motor are in the same direction. The regenerative control unit performs predetermined control so that the direction of the current flowing through the linear motor and the direction of the induced voltage are in the same direction, so the linear motor is in the regenerative (power generation) state and the braking force is applied to the piston. (Brake) acts to avoid collision with high response. Further, since the vibration energy of the piston is converted into electric power, energy saving and high efficiency can be achieved.

(2) The regenerative control section reduces the voltage applied to the linear motor so that the direction of the flowing current is
You may control so that the direction of the induced voltage induced in the said motor may become the same direction. With such a regenerative control unit, the applied voltage is reduced until it becomes smaller than the induced voltage induced in the linear motor, so that current flows from the motor side to the drive unit side, and the linear motor regenerates (power generation). Then, the braking force acts on the piston. Therefore, it is possible to avoid a collision with high response with a relatively simple structure and control, and save energy because the vibration energy of the piston is converted into electric power.
High efficiency can be achieved.

(3) The regenerative controller changes the phase of the voltage applied to the linear motor so that the direction of the flowing current and the direction of the induced voltage induced in the motor are
You may control so that it may become the same direction. By rapidly changing the phase of the applied voltage by such a regenerative control unit, the direction of the flowing current also changes rapidly, the current flows in the same direction as the induced voltage, and the linear motor rapidly regenerates (generates power). And the braking force (brake) acts on the piston. Therefore, collision can be avoided with extremely high response, and the vibration energy of the piston is converted into electric power, so that energy saving and high efficiency can be achieved.

(4) The capacity control section may control the voltage applied to the linear motor to be substantially constant in accordance with the desired capacity. Even if the amplitude of the piston increases due to the influence of disturbance vibration, the capacity control section also increases the induced voltage in proportion to it.Therefore, when the induced voltage becomes larger than the applied voltage, the motor side Current flows to the driving device side from the above to enter a regenerative state, and a braking force (brake) acts on the piston to limit the maximum amplitude value.

On the contrary, when the amplitude of the piston decreases due to the influence of the disturbance vibration, the induced voltage also decreases in proportion to the decrease in the amplitude. Therefore, the flowing current increases, and the propulsive force acts on the piston to increase the amplitude. The minimum value is limited.

Therefore, the capacity control unit can convert the surplus energy due to the disturbance vibration into electric power not only during the collision prevention but also during the normal operation, so that further energy saving and high efficiency can be achieved.

At the same time, the piston amplitude can be stabilized against disturbance vibration with a relatively simple control and configuration.

(5) The control device for the linear compressor further comprises an induced voltage detecting means for detecting the induced voltage of the linear motor, so that the capacity control unit controls the induced voltage to be substantially constant corresponding to the desired capacity. You may Even if the piston amplitude is likely to increase or decrease due to the influence of the disturbance vibration, the capacity control unit stabilizes the induced voltage that changes in proportion to the increase or decrease, so that the amplitude can be stabilized. Specifically, when suppressing the increase in the induced voltage (proportional to the amplitude), a current is made to flow in the same direction as the induced voltage to put the motor in a regenerative state to exert a braking force, and the induced voltage (proportional to the amplitude). In order to suppress the decrease of (1), a current is made to flow in the direction opposite to the induced voltage to exert an additional propulsive force to stabilize the induced voltage (proportional to the amplitude). Therefore, the piston amplitude can be stabilized against disturbance vibration with relatively high accuracy. At the same time, high response collision avoidance, energy saving during normal operation, and high efficiency can be achieved.

(6) The control drive device of the linear compressor further comprises a piston displacement detecting means for detecting the displacement of the piston, and the capability control section controls the piston displacement to be substantially constant corresponding to the desired capability. Good. When such a capacity control unit directly detects displacement and suppresses the increase in displacement, a current is caused to flow in the same direction as the induced voltage to put the motor in a regenerative state to apply braking force In order to suppress the decrease of the electric current, an electric current is made to flow in the direction opposite to the induced voltage to exert an additional propulsive force. Therefore, under a wide range of conditions, the piston amplitude can be stabilized against disturbance vibration with extremely high accuracy. At the same time, high response collision avoidance, energy saving during normal operation, and high efficiency can be achieved.

(7) The induced voltage detecting means may obtain the induced voltage using the instantaneous current and the instantaneous voltage at the point where the rate of change of the current is substantially zero. Since the above-mentioned capacity control unit calculates and detects the induced voltage from the current and voltage output by the driving device itself, it is not necessary to use a special speed sensor or position sensor to detect the induced voltage. .
Therefore, it is possible to stabilize the piston amplitude with respect to disturbance vibration with a relatively inexpensive structure and relatively accurately. At the same time, high response collision avoidance, energy saving during normal operation, and high efficiency can be achieved.

(8) The piston displacement detecting means may obtain the piston displacement using the instantaneous current and the instantaneous voltage at the point where the rate of change of the current is substantially zero. Since the above capacity controller detects the piston displacement by calculating from the current and voltage output by the control drive device itself, it is necessary to use a special speed sensor or position sensor to detect the piston displacement. Absent. Therefore, it is possible to stabilize the piston amplitude with respect to the disturbance vibration with extremely low accuracy and with extremely high accuracy. At the same time, high response collision avoidance, energy saving during normal operation, and high efficiency can be achieved.

(9) The control drive device for the linear compressor may be mounted on a vehicle for use. by this,
The vibration energy generated when the vehicle is running acts on the piston of the linear compressor as disturbance vibration, and when braking the piston, the linear compressor is in a regenerative state, and the vibration energy of the vehicle that was previously wasted is converted to electrical energy. Can be collected. Further, by entrusting the compression operation of the linear compressor to the disturbance vibration, it is possible to reduce drive power and save energy. Furthermore, it can be expected to improve the fuel efficiency of the car.

(10) The driving device may include one power source and a battery connected in parallel to the power source. With such a configuration, it is possible to regenerate electric power in the battery, improve regeneration efficiency, and also protect the voltage increase that occurs during regenerative braking. Further, when the battery is a power source for an electric vehicle or a hybrid vehicle, for example, the fuel efficiency of the vehicle can be improved.

The control drive method of the linear compressor of the present invention is as follows.
A method for controlling and driving a linear compressor including a cylinder supported in a closed container, a piston movably supported in the cylinder by a spring member, and a linear motor that applies thrust to the piston in a movable direction, When it is determined that there is a risk of collision between a piston and a cylinder, predetermined control is performed so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the linear motor are the same direction. This prevents the piston and the cylinder from colliding.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a control drive device for a linear compressor according to the present invention will be described in detail below with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 is a block diagram of a control drive device (hereinafter referred to as "control drive device") for a linear compressor according to a first embodiment of the present invention.

The control drive device is a device for controlling and driving the linear compressor 1, and has a rectifying diode 21, a smoothing capacitor 34, a control unit 33, and a drive unit 22. The control unit 33 includes an ability control unit 24, a displacement detection unit 28, and a collision prevention unit 30. The controller 33 sets the capacity command value for setting the capacity (output) of the linear compressor 1 to the setter 25.
To receive from. The driving unit 22 includes four energizing elements (IG
BT) 36 and flywheel diode 35.

The linear compressor 1 comprises a cylinder portion 2 and a motor portion 3. The cylinder portion 2 includes a piston 4, and the displacement of the piston 4 is detected by a displacement sensor 27. The motor unit 3 includes a magnet 7, an armature winding 9, and a support spring (resonant leaf spring) 6, and constitutes a linear motor.

The control drive device is supplied with power from the commercial power supply 20, the AC voltage thereof is rectified by the rectifying diode 21, and the smoothing capacitor 34 converts the AC voltage into a DC voltage with less ripples. In the case of a vehicle such as an automobile, instead of obtaining the DC voltage from the smoothing capacitor 34, the battery 2
A DC voltage is supplied from 3. Then, this DC voltage is supplied to the four energizing elements (IGB, U, V, X, Y) in the drive unit 22.
The AC voltage and current are converted by the switching operation of T) and supplied to the motor unit 3 in the linear compressor 1 to drive the compressor 1.

Next, the steady driving state of the control drive device will be described with reference to FIGS. 2 and 3 (a).

FIG. 2 shows a voltage V applied to the motor unit 3 of the linear compressor 1 in a steady driving state, a current I flowing in the winding 9 of the motor unit 3, and induction generated in the winding 9 of the motor unit 3. FIG. 3 is a diagram showing the relationship between the voltage E and the displacement X of the piston 4, and FIG. 3A is an equivalent circuit diagram at that time. The actual applied voltage is a PWM-modulated sine wave as shown in FIG. 4, but is an ideal sine wave for the sake of explanation. The direction of the induced voltage E is opposite to the applied voltage V, as shown in the equivalent circuit of FIG.

Referring to the applied voltage V in FIG. 2, the current I has a phase delayed by θ due to the influence of the motor inductance (L shown in FIG. 3A). Further, the phase of the displacement X of the piston 4 is 90 degrees from the current I.
° The phase is delayed. This is because the linear compressor 1 uses mechanical resonance, and thus the phase of the displacement X and the force applied thereto is deviated by 90 °. The phase of force (phase of thrust from the motor) is the phase of current I. Here, the magnitude of the thrust acting on the motor is determined by the thrust constant BL (thrust generated per unit current) to the current value I.
It is the value multiplied by.

Next, since the phase of the induced voltage E is the same as the phase of the velocity, it is 90 ° ahead of the phase of the displacement X, which is the same as the phase of the current. Here, the magnitude of the induced voltage E is a value obtained by multiplying the thrust constant BL by the speed v.

As described above, the driving state of the linear compressor 1 in a steady state is summarized, the applied voltage has a frequency equal to the mechanical resonance frequency, the phase of the current I of the linear motor and the phase of the induced voltage E. Are the same, and the directions of the current I and the induced voltage E are opposite.

Next, the ability control method will be described.
Returning to FIG. 1, the setting device 25 is for setting the capacity (output) of the linear compressor 1, and sends the capacity command value to the capacity control unit 24. The capability control unit 24 replaces the capability command value with the current I, the voltage V, and the displacement X, and controls them.
The energization elements U, V, X and Y of the drive unit 22 are switched, and the output of the drive unit 22 is controlled so that a desired applied voltage to the linear motor, motor current, and piston displacement can be obtained.

Here, the feedback value of the applied voltage V output to the linear motor is the DC voltage detection circuit 29.
It can be known by performing a calculation using the voltage detected in step S3 and the voltage duty ratio output by the controller 33 itself. Further, the feedback value of the current I flowing through the linear motor can be known from the output from the current detection unit 26. Regarding the feedback value of the piston displacement X, a physical displacement sensor 27, which will be described later,
It can be known from the output from the displacement detection unit 28 obtained by calculation from the electric factor.

FIG. 5 is a control flowchart in the capacity control section 24. First, the capability control unit 24 inputs a desired capability (capability command) (101), and then detects an actual capability (output) (102). The actual ability is obtained by the feedback values of the applied voltage V, the current I, and the displacement X recognized as described above. Then, the desired ability value and the actual ability value are compared (103). If the desired ability is changed, the internal command value is updated (104). If the desired ability is not changed, the internal command value is not updated.
The output of the drive unit 22 is controlled so that the capacity has a desired value (105).

Next, the collision preventing means 30 which is a main part of the control drive device according to the present invention will be described.

As shown in FIG. 1, the collision prevention means 30 is provided with a regenerative control section 31, and displacement information of the piston 4 of the linear compressor 1 is constantly inputted from the displacement detection section 28. When this displacement exceeds the allowable value, the regeneration control unit 31 causes the piston 4 to move.
Detecting the risk of collision between the cylinder 2 and the cylinder 2, the drive signal for the regenerative mode is output to the drive unit 22 to bring the linear compressor 1 into the regenerative state and apply the braking force to the piston 4.

FIG. 6 shows a control flowchart in the regenerative controller 31. The regenerative controller 31 detects the stroke of the piston 4 (displacement of twice the amplitude) based on the displacement information of the piston 4 from the displacement detector 28 (20
1) determine if it is greater than the allowed value (20
2) If it is larger, the drive signal for the regeneration mode is output to the drive unit 22 (203).

Here, in order to bring the linear compressor 1 into the regenerative state, as shown in the equivalent circuit (during regenerative operation) of FIG.
The current I should flow in the same direction as the induced voltage E,
For example, by making the applied voltage V in FIG. 3B smaller than the induced voltage E, the current I can be made to flow as shown in FIG. In this state, a negative thrust force (braking force) acts on the piston 4 and sudden braking is performed.

FIG. 7 shows the result of comparison of the change over time of the stroke by this control and the conventional control. In the figure, the solid line shows the stroke reduction when this control is performed, and the broken line shows the stroke reduction when the current is reduced as in the conventional case.
It is apparent that the stroke can be reduced with high response, that is, collision can be avoided by performing this control.

As described above, according to this embodiment, collision avoidance can be performed with high response, and since the vibration energy of the piston is converted into electric power, energy saving and high efficiency can be achieved.

(Second Embodiment) With reference to FIG. 8, a specific operation of the regenerative controller 31 will be described. FIG. 8A is a waveform diagram of each part in the steady state of the linear compressor 1. In the figure, as described above, the current I is delayed with respect to the applied voltage V, and the induced voltage E is generated in the same phase (the direction is opposite).

Now, in this state, the collision prevention means 3 as described above.
If the danger of collision is detected at 0, the regeneration control unit 31 reduces the applied voltage V as shown in FIG. 8B (hereinafter, such control is referred to as “voltage reduction control”). As a result, when the applied voltage V becomes smaller than the induced voltage E, the current I flows in the direction opposite to the steady state. In the state of FIG. 8B, the current I is being sent to the power supply side by the induced voltage E of the linear compressor 1 (see FIG. 3).
(See (b)), which is a regeneration (power generation) state, and the braking force acts on the piston 4. As a result, FIG.
As shown in (c), the amplitude of the piston 4 is suppressed, the induced voltage E proportional thereto is reduced, and the current I flows in the original direction again. The induced voltage E (proportional to the amplitude of the piston 4) is suppressed and the motor operates in a steady state after braking.

Explaining with the flowchart of FIG. 6, the regeneration control unit 31 detects a stroke (displacement of twice the amplitude) (201) and determines whether it is larger than an allowable value (202). If it is larger, "voltage reduction control" is performed as the output control of the drive unit 22 (203). Here, in order to actually reduce the voltage, the applied voltage can be reduced by reducing the duty ratio of the PWM-modulated voltage in FIG. That is, the duty ratio on the energization elements U and V side in FIG. 1 is reduced. Also, FIG.
The regenerative current of (b) flows to the power supply side through the diodes Du and Dv when the duty is OFF.

The regenerative control unit 31 according to the present embodiment also makes it possible to reduce strokes with high response as shown in FIG. 7, that is, avoid collision, as in the above-described embodiments.

As described above, according to the present embodiment, it is possible to avoid a collision with high response with a relatively simple structure and control, and since the vibration energy of the piston is converted into electric power, it is possible to save energy. High efficiency can be achieved.

(Third Embodiment) Another operation of the regeneration control unit 31 will be described with reference to FIG. FIG. 9A is a waveform diagram of each part in the steady state of the linear compressor 1,
As described above, the current I is delayed with respect to the applied voltage V, and the induced voltage E is generated in the same phase (the direction is opposite).

If the danger of collision is detected by the collision prevention means 30 in this state, the regeneration control unit 3
No. 1 delays the phase of the applied voltage V and reduces the applied voltage V, as indicated by point A in FIG. 9B (hereinafter, such control is referred to as “voltage phase control”). As a result, as shown at the point B, the applied voltage V immediately becomes smaller than the induced voltage E, and the current I flows in the direction opposite to the steady state.
The state after the point B in FIG. 9B is a state in which the current I is caused to flow to the power supply side by the induced voltage E of the linear compressor 1 (see FIG. 3B), so that the regeneration (power generation) is apparent. In this state, the braking force acts on the piston 4. As a result, as shown in FIG. 9C, the amplitude of the piston 4 is suppressed, the induced voltage E proportional thereto is reduced, and the current I flows in the original direction again. Then, the operation is performed in a steady state after braking in which the induced voltage E (proportional to the amplitude of the piston 4) is suppressed.

Explaining with the flow chart of FIG. 6, the regeneration control unit 31 first detects a stroke (displacement of twice the amplitude) (201), determines whether or not it is larger than an allowable value (202), and determines that it is larger. In this case, "voltage phase control" is performed as the output control of the drive unit 22 (203).

When the current is mainly controlled in the steady state, first, the current phase may be changed (current phase control). For example, in the case of FIG. 9B, the phase of the current I is opposite to the phase of the induced voltage E, or
In the case of FIG. 3B, the phase of the current I is controlled so that the phase of the current I is in the same direction as the phase of the induced voltage E. With this, the same effect can be obtained.

The characteristic of this phase control is that the braking force can be immediately applied, and the collision can be avoided with a higher response than in the case of the voltage reduction.

As described above, according to the present embodiment, collision avoidance can be performed with extremely high response, and since the vibration energy of the piston is converted into electric power, energy saving and high efficiency can be achieved.

(Embodiment 4) Another operation of the capability controller 24 will be described with reference to FIG. In the present embodiment, particularly, control for efficiently driving the linear compressor 1 by utilizing the disturbance vibration of the linear compressor 1 will be described.

FIG. 10A is a waveform diagram of each part in the steady state of the linear compressor 1. In the figure, the current I lags behind the applied voltage V and is in phase with it (the direction is opposite).
The induced voltage E is generated at.

Now, assuming that the applied voltage V is constant and the vibration of the piston 4 is promoted by the disturbance vibration near the resonance frequency, the induced voltage E increases and the current I increases as shown in FIG. 10 (b). Get smaller. In this state, the compression operation is assisted by the disturbance vibration, and the same capability (output) as that obtained when there is no disturbance vibration is obtained with a small amount of electric power.

Further, if the amplitude is promoted until the induced voltage E becomes equal to the applied voltage V due to the disturbance vibration, the current I becomes zero as shown in FIG. 10 (c). In this state, the compression operation is 100% assisted by the disturbance vibration, and the same capability (output) as that obtained when there is no disturbance vibration at zero power is obtained.

Next, if the amplitude is further promoted by the disturbance vibration until the induced voltage E becomes larger than the applied voltage V, the current flows in the opposite direction as shown in FIG. 10 (d). In this state, the compression operation is 100 due to the disturbance vibration.
% It is in the state of being assisted and generating electricity, and in the state of generating the same capacity (output) as when there is no disturbance vibration while generating electricity.

Further, when the vibration of the piston 4 is braked by the disturbance vibration, the induced voltage E also decreases, so that the flowing current I increases and the propulsive force is additionally applied to the piston 4 to change the amplitude. Take feedback to increase. The acceleration or braking of the piston vibration due to this disturbance vibration is determined by the phase relationship between the disturbance vibration and the piston vibration.

Therefore, by detecting the disturbance vibration and the phase of the piston vibration, it is possible to control the piston vibration so that it is always promoted by the disturbance vibration or is always damped.

The disturbance vibration can be detected by detecting the actual displacement or phase of the piston 4 and comparing the detected value with the displacement or phase of the piston determined by the capability command. When the disturbance vibration is detected, the applied voltage V is controlled to a constant value (applied voltage constant control) or the upper limit value of the applied voltage V is limited to enable efficient driving. At this time, the applied voltage V may be controlled to a constant value or the upper limit value may be limited only when the magnitude of the detected disturbance vibration is larger than a predetermined value.

Regarding the control at the time of detecting the above-mentioned disturbance vibration, the control in the capacity control section 24 will be described with reference to the flowchart of FIG. When the disturbance vibration is detected, the desired capability (capability command) is input as an applied voltage from the setter 25 (10
1) Then, the applied voltage is detected as an actual capability (10
2). Then, the desired value and the actual value are compared (103),
If the desired value has been changed, the internal command value is updated (10
4) If it has not been changed, it is not updated and the output of the drive unit 22 is controlled (applied voltage constant control) so that the applied voltage becomes substantially equal to a desired constant value (105).

As described above, according to this embodiment, surplus energy due to disturbance vibration can be converted into electric power during normal operation, and further energy saving and high efficiency can be achieved. At the same time, the piston amplitude can be stabilized against disturbance vibration with a relatively simple control and configuration.

(Embodiment 5) In this embodiment, the capacity of the linear compressor 1 is controlled so that the induced voltage E proportional to the amplitude of the piston 4 becomes constant (hereinafter, such control will be described as "constant induced voltage"). Control. ").

First, a method of detecting the induced voltage E will be described. In FIG. 1, the induced voltage detection unit 32 detects the induced voltage E from the current information from the motor current detection unit 26 and the voltage information output by the control unit 33 itself.

Specifically, in FIG. 2, the current phase is 9
At points A and D near 0 ° and 270 °, the rate of change in current (dI / dt) is close to zero, so the induced voltage E can be calculated from the following equation (1) from the equivalent circuit shown in FIG. It is represented by. E = V−R · I−L (dI / dt) ≈V−R · I (1)

In the regenerative state, the induced voltage E is expressed by the following equation (2) from the equivalent circuit shown in FIG. 3 (b). E = V + R · I + L (dI / dt) ≈V + R · I (2)

Therefore, if the motor winding resistance R is known in advance, the instantaneous voltage V (value at points B and C) and the current I
The induced voltage E can be calculated from (values at points A and D).

As described above, while detecting the induced voltage E, the induced voltage E may be controlled to have a constant value according to the capacity of the linear compressor 1.

The induced voltage E is adjusted to a desired value by changing the voltage V and the current I. Even if the induced voltage E and the current I do not match in phase because they are out of resonance, the amount of change as a function is small near 90 ° and 270 ° of the sine wave, and a relatively small error occurs. Fits.

The state transition will be described with reference to FIG. Figure 1
1 (a) is a waveform diagram of each part in the steady state of the linear compressor 1, and when the piston amplitude is promoted by disturbance vibration near the resonance frequency, as shown in FIG. 11 (b),
In order to keep the induced voltage E constant, the applied voltage V is lowered so that the current I becomes smaller. In this state, the compression operation is assisted by the disturbance vibration, and the same capacity (output) is obtained with a small amount of electric power.

Next, assuming that the piston amplitude is further promoted by the disturbance vibration, in order to make the induced voltage E constant, the applied voltage V is further lowered and the current I is reversed as shown in FIG. 11 (c). Flow in the direction. In this state, the compression operation is 100% assisted by the disturbance vibration, and power is being generated, which means that the same capacity (output) is obtained while power is being generated.

When the piston amplitude is damped by the disturbance vibration, the flowing current I is increased in order to make the induced voltage E constant, so that a propulsive force is additionally applied to the piston 4 to increase the piston amplitude. So take feedback.

The control in the capacity control section 24 will be described with reference to the flowchart of FIG. The desired capability is input as an induced voltage from the setting device 25 (101), and then the actual capability is detected as an induced voltage using the method described above (102). Then, the desired value and the actual value are compared (103), and if the desired value is changed, the internal command value is updated (104). If not changed, the internal command value is not updated, and the induced voltage is maintained at a desired constant value. The output of the driving device is controlled so as to be substantially equal to the value (control of constant induced voltage) (105).

The control based on the induced voltage is equivalent to the control of the amplitude under the condition that the frequency is constant, and the amplitude can be stabilized with high accuracy.

As described above, according to this embodiment, the piston amplitude can be stabilized against disturbance vibration with relatively high accuracy. At the same time, high response collision avoidance, energy saving during normal operation, and high efficiency can be achieved.

(Embodiment 6) In this embodiment, the displacement of the piston 4 is directly detected and the capacity of the linear compressor 1 is controlled to be constant. (Hereinafter, such control is referred to as "stroke constant control".)

First, a method of detecting a reciprocating stroke (hereinafter referred to as "stroke") as piston displacement will be described.

Here, the stroke is detected using the induced voltage described in the fifth embodiment and the frequency of the applied voltage.

First, since the maximum value of the induced voltage E is known, the maximum value v of the speed of the piston 4 is expressed by the following equation (3). v = E / (BL) (3) (BL is a thrust constant) When the maximum value v of this speed is used to express the amplitude X,
Equation (4) is obtained. X = v / ω = E / (ω · BL) = (VR−I) / (ω · BL) (4) where ω is the angular velocity, and ω = 2π when the frequency is f.
f, and the equation (5) is obtained. X = (V−R · I) / (2πf · BL) (5) Therefore, since the reciprocating stroke ST is twice the amplitude,
It is expressed by equation (6). ST = 2 (VR-I) / (2πf ・ BL) (6)

As described above, the stroke ST can be detected if the motor winding resistance R, the instantaneous voltage V, the current I, the applied frequency f, and the thrust constant BL are known.

FIG. 12 shows a control flowchart for stroke detection in the displacement detector 28. In FIG. 12, it is judged whether or not the phase of the current I is 90 ° (301), and if the current phase is 90 °, the instantaneous current I at that time is detected (302). Next, the instantaneous voltage V is calculated from the DC voltage and the duty ratio (303), and the induced voltage E is calculated from the instantaneous voltage V and the instantaneous current I (304).
Then, the stroke ST is obtained using the above equation (6) (305).

While detecting the stroke in this way, control may be performed so that the detected stroke becomes a constant value according to the capacity of the linear compressor 1. In order to actually adjust the stroke, the voltage V or the current I is changed so that the stroke has a desired value.

FIG. 11 also explains the state transition in this control. The fifth embodiment is performed under a constant frequency.
Since it is the same as making the induced voltage constant described in 1), the description is omitted.

The control of the capacity control unit 24 will be described with reference to the flowchart of FIG. The desired ability is input as a stroke from the setter 25 (101), and then the actual ability is detected as a stroke using the method described above (10).
2). Then, the desired value and the actual value are compared (103),
If the desired value has been changed, the internal command value is updated (10
4) If it has not been changed, it is not updated and the output of the drive device is controlled so that the stroke is substantially constant (stroke constant control) (105).

By controlling with this stroke, the amplitude can be accurately controlled even if the resonance frequency changes.

As described above, according to the present embodiment, it is possible to stabilize the piston amplitude against disturbance vibration under a wide range of conditions with extremely accurate and inexpensive construction. At the same time, high response collision avoidance, energy saving during normal operation, and high efficiency can be achieved.

(Seventh Embodiment) FIG. 13 is a diagram showing a state in which the linear compressor 1 is mounted on a vehicle. In general, it is known that a maximum of 30 G of vibration acceleration is generated in an automobile, depending on the mounting location. Therefore, FIG.
As shown in FIG. 5, the linear compressor 1 is mounted on an automobile, and the linear compressor 1 according to the above-described embodiment is controlled and driven to prevent the above-mentioned collision, assist compression by disturbance vibration, save energy by power generation, and improve reliability. It is clear that a special effect can be obtained for improving sexuality. Particularly when the piston is mounted in the vertical direction, the vibration force from the road surface can be effectively utilized.

Further, in an eco-car such as an electric car, a hybrid car and a fuel cell car, which has been attracting attention in recent years, the present embodiment is promising also from the viewpoint of improving the fuel efficiency of the car. Further, the car air conditioner using a CO ₂ (carbon dioxide) refrigerant is inferior in efficiency of the refrigerant as compared with the conventional refrigerant HFC134a, so that an effect of improving the efficiency can be expected also in this respect.

FIG. 14 is a diagram of mounting on the engine. The linear compressor 1 is attached to the engine 42, and the axis line of the piston 4 is the piston 43 of the engine 42.
It is in the same direction as the axis of. By doing this,
The exciting force from the engine 42 can be effectively utilized.

Further, the vertical vibration (vertical direction in FIG. 14) generated during the operation of the linear compressor 1 can be absorbed by the damping mechanism 40 of the engine 42, and the linear compressor 1 to the vehicle chassis 41 can be absorbed. Is less likely to be transmitted, and the vibration actually felt by the occupant can be reduced.

As described above, according to the present embodiment, it is possible to recover the wasted vibration energy of the vehicle as electric energy in the past and to entrust the compression operation of the linear compressor to the disturbance vibration. Further, the driving power is reduced and energy saving can be achieved. In addition, it can be expected to improve car fuel efficiency and contribute to the environment.

(Embodiment 8) As shown in FIG. 15, a power source unit is connected in parallel with a commercial power source 20, and a battery 23
May be provided. By providing the battery 23 in this way, the regenerative current flowing from the linear motor 3 to the power supply side through the diodes Du and Dv is charged in the battery 23, so that the regeneration can be efficiently performed. At the same time, it is possible to suppress the increase in the voltage of the DC part due to regeneration,
It also protects the energizing elements.

In particular, the above-described eco-car battery has no problem in battery reliability because it is designed to sufficiently withstand a large regenerative current from the vehicle motor.

In another embodiment in which the battery is not connected, the capacitor 34 is charged with a regenerative current, or power or current is supplied to another load connected to the DC portion to regenerate the power. Will be done.

As described above, according to the present embodiment, by regenerating the electric power in the battery, the regenerative efficiency is improved and the voltage rise generated during the regenerative braking can be protected. Further, when the battery is a power source for an electric vehicle or a hybrid vehicle, for example, the fuel efficiency of the vehicle can be improved.

[0100]

According to the control drive device for a linear compressor of the present invention, by controlling the linear compressor in a regenerative state, collision can be avoided with high response and reliability is improved. Further, since the surplus vibration energy of the piston is converted into electric power, energy saving and high efficiency can be achieved.

Further, the regenerative state may be controlled by reducing the voltage applied to the linear compressor, which makes it possible to avoid collision with high response with a relatively simple structure and control. Cost performance improves.

Alternatively, the phase may be rapidly changed to the regenerative state by changing the phase of the voltage applied to the linear compressor, which allows the collision to be avoided with extremely high response with a relatively simple structure and control. The cost performance and reliability can be improved.

The steady-state capacity may be controlled by controlling the voltage applied to the linear compressor to be substantially constant, and the surplus energy due to the disturbance vibration is converted into electric power not only during collision prevention but also during normal operation. It can be converted, and further energy saving and high efficiency can be achieved. At the same time, the piston amplitude can be stabilized against disturbances, improving comfort.

Alternatively, the steady-state capacity may be controlled by controlling the voltage induced in the motor of the linear compressor to be substantially constant, and this can also achieve further energy saving and higher efficiency. At the same time, the piston amplitude can be stabilized relatively accurately and comfort is improved.

Further, the capacity may be controlled by controlling the piston displacement of the linear compressor to be substantially constant, so that further energy saving and higher efficiency can be achieved. At the same time, the piston amplitude can be stabilized extremely accurately over a wide range of conditions, improving comfort.

Further, the induced voltage may be controlled to be substantially constant without using a special speed sensor or position sensor to control the steady-state capability. As a result, cost performance is improved and the device can be downsized. Furthermore, the piston amplitude can be stabilized with relatively high accuracy, and comfort is improved.

Alternatively, the capacity may be controlled by detecting the displacement and controlling the displacement to be substantially constant. Also by this, the cost performance can be improved, the device can be downsized, the piston amplitude can be stabilized with relatively high accuracy, and the comfort can be improved.

Further, the linear compressor and its control drive device may be mounted in a vehicle, and the vibration energy of the vehicle, which has been wasted in the past, can be recovered as electric energy, thus saving energy and improving fuel efficiency of the vehicle. Can be planned.

A battery connected in parallel with the power source of the driving device may be provided to regenerate electric power in the battery. As a result, the regenerative efficiency is improved, and the voltage rise that occurs during regenerative braking can be protected and the reliability is also improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control drive circuit of a linear compressor according to the present invention.

FIG. 2 is a phase relationship diagram of a linear compressor (steady state).

FIG. 3A is an equivalent circuit diagram of a linear compressor (during steady state), and FIG. 3B is an equivalent circuit diagram of a linear compressor (during regeneration).

FIG. 4 is a waveform diagram of a PWM applied voltage.

FIG. 5 is a control flowchart of a capacity control unit according to the embodiment of the present invention.

FIG. 6 is a control flowchart of a regenerative controller according to the embodiment of the present invention.

FIG. 7 is a comparison diagram of braking time according to the present invention and a conventional example.

8A and 8B are a phase relation diagram 2 (steady state) of the linear compressor according to the second embodiment, and a phase relation diagram 1 (voltage reduction) of the linear compressor according to the control of the present invention. Phase relationship of linear compressor Figure 3 (after braking).

9A and 9B are (a) a phase relationship diagram of a linear compressor in a third embodiment (steady state), (b) a phase relationship diagram of a linear compressor according to the control of the present invention (voltage reduction), and FIG. The phase relation figure 2 (phase control) of the linear compressor by control of the present invention.

10 (a) is a phase relationship diagram of the linear compressor in the fourth embodiment (steady state), and FIG. 10 (b) is a phase relationship diagram of the linear compressor according to the control of the present invention (voltage constant control).
(C) Phase relationship diagram 4 of the linear compressor under the control of the present invention
(Voltage constant control), (d) Phase relationship of the linear compressor according to the control of the present invention FIG. 5 (Voltage constant control).

11 (a) is a phase relationship diagram of the linear compressor according to the fifth embodiment (steady state), and FIG. 11 (b) is a phase relationship diagram of the linear compressor according to the control of the present invention (induced voltage / stroke constant control). , (C) Phase relationship diagram 7 according to the control of the present invention
(Induction voltage / stroke constant control).

FIG. 12 is a control flowchart of a displacement detector according to the sixth embodiment.

FIG. 13 is a diagram for explaining how the linear compressor according to the seventh embodiment is mounted on a vehicle.

FIG. 14 is a diagram illustrating how the linear compressor according to the seventh embodiment is attached to a vehicle engine.

FIG. 15 is a diagram illustrating a battery provided in parallel with a commercial power source in Embodiment 8.

FIG. 16 is a vertical cross-sectional view of a general linear compressor.

[Explanation of symbols]

1 linear compressor 2 Cylinder part 2a Cylinder inner peripheral wall 2b cylinder head 3 Motor part 4 pistons 4a Piston compression surface 5 piston rod 6 Support spring (resonant leaf spring) 20 Commercial power supply 21 Rectifier diode 22 Drive 23 Battery 24 Capacity control unit 26 Current detector 27 Displacement sensor 28 Displacement detector 29 DC voltage detection circuit 30 Collision prevention unit 31 Regenerative controller 32 Induced voltage detector 33 Control unit 34 Smoothing capacitor (Gold capacitor) 35 Flywheel diode 36 Current-carrying element (IGBT)

Continued front page    (72) Inventor Mitsuo Ueda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 3H045 AA03 AA25 BA01 BA31 BA41                       CA21 DA41 DA45 EA26 EA34                       EA42 EA49                 3H076 AA02 BB26 BB28 BB43 CC03                 5H540 AA10 BA03 FA06 FB05 FC02                       FC03                 5H633 BB08 BB10 GG02 GG04 GG09                       GG16 GG21 GG22 GG23 HH03                       HH23 JA02 JB07

Claims (18)

[Claims] 1. A cylinder supported in a closed container,
A device for controlling and driving a linear compressor, which comprises a piston movably supported in the cylinder by a spring member and a linear motor that applies thrust to the piston in a movable direction, wherein AC power is supplied to the linear motor. Drive unit for reciprocating the piston, a capacity control unit for controlling the linear motor so that the capacity of the linear compressor reaches a desired value, and a collision prevention unit for preventing the piston and the cylinder from colliding. The collision prevention means includes a regenerative control unit that performs predetermined control so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the linear motor are in the same direction. A control drive device for a linear compressor, which is provided. 2. The regenerative control unit, in the predetermined control, directs the linear motor so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the motor are the same. 2. The control drive device for a linear compressor according to claim 1, wherein the applied voltage is reduced. 3. The regenerative control unit controls the linear motor so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the motor are the same in the predetermined control. 2. The control drive device for a linear compressor according to claim 1, wherein the phase of the applied voltage is changed. 4. The capacity control unit controls the voltage applied to the linear motor to be substantially constant according to a desired capacity, according to any one of claims 1 to 3. Control drive device for linear compressor. 5. An induced voltage detecting means for detecting an induced voltage of a linear motor is further provided, and the capability control section controls the induced voltage to be substantially constant corresponding to a desired capability. The control drive device for a linear compressor according to any one of claims 1 to 3. 6. The control drive of a linear compressor according to claim 5, wherein the induced voltage detecting means obtains the induced voltage by using an instantaneous current and an instantaneous voltage at a point where the rate of change of the current is substantially zero. apparatus. 7. A piston displacement detecting means for detecting displacement of a piston is further provided, and the capability control unit controls the displacement of the piston to be substantially constant according to a desired capability. The control drive device for the linear compressor according to claim 3. 8. The control drive of a linear compressor according to claim 7, wherein the piston displacement detection means obtains the piston displacement by using an instantaneous current and an instantaneous voltage at a point where the rate of change of the current is substantially zero. apparatus. 9. The control drive device for a linear compressor according to claim 1, wherein the control drive device is mounted on a vehicle. 10. A power source and a battery connected in parallel to the one power source.
10. The control drive device for the linear compressor according to claim 9. 11. A linear compressor including a cylinder supported in a closed container, a piston movably supported in the cylinder by a spring member, and a linear motor that applies thrust to the piston in a movable direction is controlled. When it is determined that there is a risk of collision between the piston and the cylinder, the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the linear motor are in the same direction. A method for controlling and driving a linear compressor, characterized in that the piston and the cylinder are prevented from colliding with each other by performing a predetermined control. 12. In the predetermined control, the applied voltage to the linear motor is reduced so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the motor are in the same direction. The control drive method for a linear compressor according to claim 11, wherein: 13. The phase of the voltage applied to the linear motor so that the direction of the current flowing through the linear motor and the direction of the induced voltage induced in the motor are in the same direction in the predetermined control. 12. The method for controlling and driving a linear compressor according to claim 11, characterized in that 14. The control drive of the linear compressor according to claim 11, wherein the voltage applied to the linear motor is controlled to be substantially constant in accordance with a desired capacity. Method. 15. The method according to claim 11, further comprising detecting an induced voltage of the linear motor, and using the detected induced voltage to control the induced voltage to be substantially constant corresponding to a desired capability. 13. The control driving method for the linear compressor according to any one of 13. 16. The control drive method for a linear compressor according to claim 15, wherein the induced voltage is obtained by using an instantaneous current and an instantaneous voltage at a point where the rate of change of the current is substantially zero. 17. The displacement of the piston is detected, and the displacement of the piston is controlled to be substantially constant in accordance with a desired capacity by using the detected displacement of the piston. 2. A method for controlling and driving a linear compressor according to any one of 1. 18. The control drive method for a linear compressor according to claim 17, wherein the piston displacement is obtained by using an instantaneous current and an instantaneous voltage at a point where the rate of change of current is substantially zero.