JP2019030054A - Driving device - Google Patents

Abstract

To provide a driving device capable of maintaining power consumption low even in a case where charge/discharge of a dielectric is repeated highly frequently.SOLUTION: A driving device comprises an actuator and a power supply part. The actuator includes a dielectric. The power supply part is configured to apply a voltage to the actuator. The power supply part includes a power accumulation part configured to accumulate power discharged by the actuator. The driving device is capable of maintaining power consumption low since power is recovered by the power accumulation part even in a case where the actuator is discharged frequently.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive device.

  Japanese Patent Laying-Open No. 2003-174205 (Patent Document 1) discloses a driving device including a dielectric actuator. In this drive device, a desired operation by the dielectric actuator is realized by controlling the timing of charging and discharging the dielectric (see Patent Document 1).

JP 2003-174205 A

  The actuator having a dielectric as disclosed in Patent Document 1 consumes power only at the time of charge / discharge immediately after closing and opening of the switch, and can retain electric charge without continuing to apply voltage. . Therefore, in such an actuator, when the voltage of the actuator is maintained, it is not necessary to continue the application of the voltage, so that the power consumption is low.

  However, for example, if charging and discharging of the dielectric material is repeated at a high frequency, a voltage is frequently applied to the actuator, so that the power consumption is not necessarily low.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a drive device that can maintain low power consumption even when charge and discharge of a dielectric are repeated frequently. It is.

  The drive device according to the present invention includes an actuator and a power supply unit. The actuator includes a dielectric. The power supply unit is configured to apply a voltage to the actuator. The power supply unit includes a power storage unit configured to store electric power discharged by the actuator.

  In this drive device, the electric power discharged by the actuator is stored in the power storage unit. Therefore, according to this drive device, even if the actuator is frequently discharged, the power is collected by the power storage unit, so that the power consumption can be kept low.

  Preferably, in the drive device, the actuator includes a dielectric and first and second electrodes provided on the dielectric. The driving device further includes first and second switch circuits. The first switch circuit is provided between the output terminal of the power supply unit and the first electrode. The second switch circuit is provided between the input terminal of the power supply unit and the first electrode. The second electrode is connected to the ground. When the second switch circuit is open and the first switch circuit is closed, the voltage of the power supply unit is applied to the actuator. When the first switch circuit is opened and the second switch circuit is closed, the electric power discharged by the actuator is stored in the power storage unit.

  In this drive device, when the first switch circuit is closed when the second switch circuit is open, the voltage of the power supply unit is applied to the actuator while the first switch circuit is open. When the second switch circuit is closed, the electric power discharged by the actuator is stored in the power storage unit. Therefore, according to this drive device, even if the actuator is frequently discharged, the power is collected by the power storage unit, so that the power consumption can be kept low.

  More preferably, the driving device further includes an insulating circuit. The insulating circuit is provided between the second switch circuit and the input terminal.

  When the input terminal of the power supply unit and the second switch circuit are directly connected and the second switch circuit is closed, the voltage of the power storage unit is applied to the actuator. In this drive device, an insulating circuit is provided between the input terminal of the power supply unit and the second switch circuit. Therefore, according to this drive device, it is possible to prevent the voltage of the power storage unit from being applied to the actuator when the second switch circuit is closed.

  ADVANTAGE OF THE INVENTION According to this invention, even if charging / discharging of a dielectric material is repeated with high frequency, the drive device which can maintain power consumption low can be provided.

FIG. 3 is a diagram showing a circuit configuration of a drive device according to the first embodiment. It is a timing chart which shows an example of operation of a drive. FIG. 6 is a diagram showing a circuit configuration of a driving device according to a second embodiment. It is a figure which shows the circuit structure of the drive device according to a 1st modification. It is a figure which shows the circuit structure of the drive device according to a 2nd modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals and description thereof will not be repeated.

[1. Embodiment 1]
<1-1. Circuit configuration of drive device>
FIG. 1 is a diagram showing a circuit configuration of drive device 10 according to the first embodiment. As shown in FIG. 1, the drive device 10 includes a power supply unit 40, an actuator 22, switch circuits S <b> 1 and D <b> 1, and a control circuit 50. In the driving device 10, the actuator 22 operates by using the electric power supplied from the power supply unit 40.

  The power supply unit 40 includes a low voltage power supply 42, a capacitor 48, a boost converter 46, and diodes 44 and 45. The low-voltage power source 42 is a power source of several V to several tens V, for example, and is configured to supply power to the boost converter 46 and the control circuit 50. In FIG. 1, the illustration of power lines connecting the low voltage power supply 42 and the control circuit 50 is omitted.

  The positive electrode of the low-voltage power supply 42 is electrically connected to the anode of the diode 44, and the cathode of the diode 44 is electrically connected to the boost converter 46 via the node N3. The negative electrode of the low-voltage power supply 42 is electrically connected to the ground.

  The capacitor 48 is configured to supply power to the boost converter 46 and the control circuit 50, and is configured to store power discharged by the actuator 22. In FIG. 1, illustration of a power line connecting the capacitor 48 and the control circuit 50 is omitted. In addition, the storage of the electric power discharged by the actuator 22 by the capacitor 48 is hereinafter also referred to as “power recovery”. The power recovery will be described in detail later.

  One end of the capacitor 48 is electrically connected to the cathode of the diode 45 via the node N2, and is also electrically connected to the cathode of the diode 44 and the boost converter 46 via the nodes N2 and N3. The other end of the capacitor 48 is electrically connected to the ground.

  Boost converter 46 is configured to boost the output voltage to an input voltage (several tens of volts) or more. For example, the output voltage of boost converter 46 is several kV to several tens of kV. Boost converter 46 is electrically connected to switch circuit S <b> 1 via output terminal O <b> 1 of power supply unit 40.

  The actuator 22 includes a dielectric 24 and electrodes 26 and 28. The dielectric 24 is made of an elastomer material having flexibility and high dielectric constant, such as acrylic, urethane, and silicone. The dielectric 24 expands and contracts when a voltage is applied (when charged). By using the expansion and contraction of the dielectric 24, the driving device 10 drives the driving target. The capacitance (C) of the dielectric 24 is lower than the capacitance of the capacitor 48.

  Each of the electrodes 26 and 28 has elasticity and is provided on the surface of the dielectric 24. The electrodes 26 and 28 are provided at positions facing each other across the dielectric 24. The electrode 26 is electrically connected to the switch circuits S1 and D1 via the node N1. The electrode 28 is electrically connected to the ground G1. The electrodes 26 and 28 are not necessarily provided at positions facing each other with the dielectric 24 interposed therebetween. The electrodes 26 and 28 may be provided on the same surface of the dielectric 24, for example. That is, the electrodes 26 and 28 may be provided on the dielectric 24.

  Each of the switch circuits S1 and D1 is a circuit configured to open and close an electric circuit. Each of the switch circuits S1 and D1 is configured by a semiconductor switch such as a reed switch, a reed relay, or a transistor, for example. The switch circuit D1 is connected to the anode of the diode 45 through the input terminal I1 of the power supply unit 40.

  When the switch circuit S1 is closed while the switch circuit D1 is open, the output voltage of the boost converter 46 is applied to the actuator 22 and the actuator 22 is charged. Thereafter, when the switch circuit S1 is opened while the switch circuit D1 is opened, the voltage of the actuator 22 (voltage between the electrodes 26 and 28) is maintained. This is because the dielectric 24 can hold charges without continuing to apply a voltage. When the switch circuit D1 is closed while the switch circuit S1 is opened, the electric charge stored in the actuator 22 is discharged and the capacitor 48 is charged. That is, power recovery is performed.

  The control circuit 50 includes a CPU (Central Processing Unit) and a memory (not shown), and is based on a program stored in the memory (hereinafter also referred to as “internal memory”) and information from each sensor (not shown). Each circuit of the driving device 10 (for example, the boost converter 46, the switch circuits S1, D1) is controlled. It can be said that the program stored in the internal memory is a control program for controlling the operation of the actuator 22.

  For example, the control circuit 50 is configured to transmit a command value for changing the output voltage of the boost converter 46 to the boost converter 46. The command value transmitted from control circuit 50 to boost converter 46 is determined, for example, according to a program stored in internal memory.

  In addition, the control circuit 50 is configured to individually control the opening / closing of each of the switch circuits S1, D1 according to a program stored in an internal memory, for example. For example, the control circuit 50 causes the capacitor 48 to recover the electric power discharged by the actuator 22 by controlling the switch circuit D1 so that the switch circuit D1 is closed when the switch circuit S1 is open ( Power recovery).

<1-2. Power recovery>
Next, the reason why power recovery is performed in drive device 10 according to the first embodiment will be described. For example, when the switching circuits S1 and D1 are not frequently opened and closed (charging / discharging of the actuator 22), the power consumption in the driving device 10 is kept low. This is because voltage can be applied to the actuator 22 only for a short time because the actuator 22 can maintain the voltage even when voltage is not continuously applied.

  However, if the power recovery is not performed and the switch circuits S1 and D1 are frequently opened and closed, power consumption during charging / discharging of the actuator 22 occurs frequently, and the power consumption in the driving device 10 is as follows. It will not necessarily be low.

  In drive device 10 according to the first embodiment, even if switch circuits S1 and D1 are frequently opened and closed, the power discharged by actuator 22 is recovered by capacitor 48. That is, according to the drive device 10, even when the switching circuits S1 and D1 are opened and closed (charging / discharging of the actuator 22) frequently, power recovery is performed, so that power consumption can be kept low.

<1-3. Example of operation of drive device>
FIG. 2 is a timing chart showing an example of the operation of the driving device 10. Referring to FIG. 2, the horizontal axis indicates time, and the vertical axis indicates, from above, the state of the switch circuit S1, the state of the switch circuit D1, the voltage of the actuator 22, and the voltage of the capacitor 48.

  At time t0, both switch circuits S1 and D1 are open, and the voltages of actuator 22 and capacitor 48 are V0 and V50, respectively.

  When the switch circuit S1 is closed according to the control of the control circuit 50 at time t1, the output voltage (V1) of the boost converter 46 is applied to the actuator 22, and the voltage of the actuator 22 rises to V1. Thereafter, even if the switch circuit S1 is opened in a short time, the voltage of the actuator 22 is maintained at V1.

  At time t2, when the switch circuit D1 is closed according to the control of the control circuit 50, the actuator 22 is discharged, and the voltage of the actuator 22 is approximately V0 (more specifically, a voltage equivalent to a voltage V51 of the capacitor 48 described later). ) Then, the electric power discharged by the actuator 22 is recovered by the capacitor 48, and the voltage of the capacitor 48 becomes V51. As described above, since the capacitance of the capacitor 48 is sufficiently larger than the capacitance of the actuator 22 (dielectric 24), the relationship of (V51-V50) << (V1-V0) is established.

  At time t3, when the switch circuit D1 is opened and the switch circuit S1 is closed, power is supplied from the capacitor 48 to the boost converter 46, so that the voltage of the capacitor 48 decreases to V50. Then, the voltage of the actuator 22 rises to V1.

<1-4. Features>
As described above, in drive device 10 according to the first embodiment, power supply unit 40 includes capacitor 48 configured to store the electric power discharged by actuator 22.

  Therefore, according to the driving device 10, even if the actuator 22 is frequently discharged, the power is recovered by the capacitor 48, so that wasteful discharge can be prevented and power consumption can be kept low. .

[2. Second Embodiment]
Drive device 10 according to the first embodiment includes one actuator 22. However, the number of actuators included in the drive device is not limited to one. The drive device according to the second embodiment includes two actuators. Note that the number of actuators may be three or more. Below, it demonstrates centering on a different point from the said Embodiment 1. FIG.

  FIG. 3 is a diagram showing a circuit configuration of drive device 10A according to the second embodiment. As shown in FIG. 3, the drive device 10A includes a power supply unit 40, actuators 22 and 32, switch circuits S1, D1, S2, and D2, and a control circuit 50A. The main difference from drive device 10 according to the first embodiment is that actuator 32 and switch circuits S2 and D2 are added. Note that when the number of actuators is three or more, the number of switch circuits also increases.

  The actuator 32 has the same configuration as the actuator 22. That is, the dielectric 34 and the electrodes 36 and 38 are the same as the dielectric 24 and the electrodes 26 and 28 (FIG. 1), respectively.

  The electrode 36 is electrically connected to the switch circuits S2 and D2 via the node N5, and the electrode 38 is electrically connected to the ground G1 via the node N7. The switch circuit S2 is electrically connected to the boost converter 46 through the output terminal O1 of the power supply unit 40, and the switch circuit D2 is electrically connected to the capacitor 48 through the input terminal I1 of the power supply unit 40. .

  When the switch circuit S2 is closed while the switch circuit D2 is open, the output voltage of the boost converter 46 is applied to the actuator 32. When the switch circuit D2 is closed while the switch circuit S2 is opened, the electric power stored in the actuator 32 is discharged and the capacitor 48 is charged.

  The control circuit 50A includes a CPU and a memory (not shown), and each circuit of the driving device 10A (for example, the boost converter 46, the switch circuit, etc.) based on a program stored in the internal memory and information from each sensor (not shown). S1, D1, S2, D2) are controlled.

  When the control circuit 50A controls the switch circuit D2 so that the switch circuit D2 is closed while the switch circuit S2 is open, the power stored in the actuator 32 is discharged and the capacitor 48 is charged. Thus, in the drive device 10 </ b> A, the electric power discharged from each of the actuators 22 and 32 is recovered by the capacitor 48. That is, according to the drive device 10A, since the electric power discharged from each of the actuators 22 and 32 is collected, the power consumption can be kept low even if the number of actuators increases.

[3. Modified example]
Although the first and second embodiments have been described above, the present invention is not limited to the first and second embodiments, and various modifications can be made without departing from the gist thereof. Hereinafter, modified examples will be described. However, the following modifications can be combined as appropriate.

<3-1>
In the first and second embodiments, power is supplied to each actuator by the power supply unit 40. In the power supply unit 40, the output voltage is boosted to a voltage higher than that of the low-voltage power supply 42 by the boost converter 46. However, the power source that supplies power to each actuator is not limited to the power source unit 40. In the first modification, a power source that combines a low-voltage power source, a high-voltage amplifier, and a signal source supplies power to the actuator.

  FIG. 4 is a diagram showing a circuit configuration of drive device 10B according to the first modification. As shown in FIG. 4, the driving device 10B includes a power supply unit 40B, an actuator 22, switch circuits S1 and D1, and a control circuit 50B.

  The power supply unit 40 </ b> B includes a signal source 52 and a high voltage amplifier 54 in addition to the low voltage power supply 42 and the capacitor 48. The high voltage amplifier 54 is configured to amplify the input voltage from the low voltage power source 42 and output a high voltage indicating the waveform of the input signal from the signal source 52.

  The control circuit 50B is configured to control the signal waveform of the signal source 52, the output voltage of the high voltage amplifier 54, and the opening and closing of the switch circuits S1 and D1. The control circuit 50B can change the voltage applied to the actuator 22 with high responsiveness by controlling the signal source 52 and the high voltage amplifier 54.

  Also in the driving device 10B as described above, the control circuit 50B allows the capacitor 48 to recover the electric power discharged by the actuator 22 by closing the switch circuit D1 when the switch circuit S1 is open. it can.

<3-2>
In the first and second embodiments, the input terminal I1 of the power supply unit 40 and the switch circuit D1 are directly connected. However, for example, an insulating circuit may be provided between the input terminal I1 of the power supply unit 40 and the switch circuit D1.

  FIG. 5 is a diagram showing a circuit configuration of a drive device 10C according to the second modification. As shown in FIG. 5, an insulation circuit 60 is provided between the input terminal I1 of the power supply unit 40 and the switch circuit D1. The insulation circuit 60 is constituted by a transformer, for example.

  By providing the insulating circuit 60 between the input terminal I1 and the switch circuit D1, malfunction of the control circuit 50 or the like can be prevented.

<3-3>
In the first and second embodiments, the switch circuit is not provided between the electrodes 28 and 38 and the ground G1. However, a switch circuit may be provided between the electrodes 28 and 38 and the ground G1.

<3-4>
In the first and second embodiments, the power supply unit 40 includes the capacitor 48 as the power storage unit. However, the power storage unit included in power supply unit 40 is not limited to capacitor 48. For example, the power supply unit 40 may include an electric double layer capacitor instead of the capacitor 48. The power supply unit 40 only needs to include a device that can store the electric power discharged by the actuator 22.

  10, 10A, 10B, 10C, 10D Driving device, 22, 32 Actuator, 24, 34 Dielectric, 26, 28, 36, 38 Electrode, 40, 40B Power supply unit, 42 Low voltage power supply, 44, 45 Diode, 46 Boost converter , 48 capacitors, 50, 50A, 50B, 50D control circuit, 60 insulation circuit, S1, S2, D1, D2 switch circuit, G1, ground, N1, N2, N3, N4, N5, N6, N7, N8, N9 node, I1 input terminal, O1 output terminal.

Claims (3)

An actuator including a dielectric;
A power supply configured to apply a voltage to the actuator,
The power supply unit includes a power storage unit configured to store electric power discharged by the actuator. The actuator includes the dielectric, and first and second electrodes provided on the dielectric,
A first switch circuit provided between the output terminal of the power supply unit and the first electrode;
A second switch circuit provided between the input terminal of the power supply unit and the first electrode;
The second electrode is connected to ground;
When the second switch circuit is open and the first switch circuit is closed, the voltage of the power supply unit is applied to the actuator,
2. The drive device according to claim 1, wherein when the first switch circuit is open and the second switch circuit is closed, the electric power discharged by the actuator is stored in the power storage unit.   The drive device according to claim 2, further comprising an insulating circuit provided between the second switch circuit and the input terminal.