JP2011089551A - Valve device and method for driving the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device capable of efficiently boosting a boosting circuit without any adverse effect on the response speed of a valve. <P>SOLUTION: The latching type valve device includes a solenoid valve to be driven to open/close a flow passage by the conduction to a solenoid coil 54, a boosting unit 107 for generating the secondary side voltage by boosting the primary side voltage from a power source, a driving capacitor 115 which is charged by the output current from the boosting unit to supply the current to the solenoid coil when driving the solenoid valve, a conduction unit 105 which is provided between the solenoid coil and the driving capacitor to start or stop the conduction from the driving capacitor to the solenoid coil, and a control unit 101 for controlling the boosting unit and the conduction unit; and further includes an auxiliary capacitor 116 which is connected to the driving capacitor in parallel to charge the driving capacitor during the period when the conduction from the driving capacitor to the solenoid coil is stopped. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a valve device and a driving method thereof, for example, a latching solenoid valve and a driving method thereof.

  A latching solenoid valve (hereinafter also simply referred to as a valve) is conventionally used to open and close a fluid path such as water or gas, and a solenoid is moved by energizing the solenoid coil to open / close the flow path. Switch the closed state. When maintaining the open state or the closed state of the flow path, the valve holds the plunger by using the magnetic force of the permanent magnet or the elastic force of the spring without using electric power. On the other hand, when switching between the open state and the closed state, the valve moves the plunger using electric power. Therefore, the latching solenoid valve consumes the largest amount of power when switching between the open and closed states.

  As a power source for such a valve, it is considered to use a hydroelectric generator or a battery. A hydroelectric generator or battery is advantageous in that it does not require power wiring work unlike an AC power source. When a hydroelectric generator is used as a power source, a storage capacitor is connected to the output. However, the output voltage of the storage capacitor changes depending on the amount of charge accumulated in the storage capacitor. Further, when a battery is used as a power source, the number of batteries is limited to reduce the size of the valve device and to reduce the labor and cost of battery replacement. In this case, the power of the power source is limited. Therefore, when a hydroelectric generator or a battery is used as a power source, a switching regulator type DC-DC converter (hereinafter also simply referred to as a booster circuit) is required to efficiently supply stable power. Note that this type of booster circuit varies in output capability and efficiency in accordance with the DUTY of the switching operation.

  In order for the booster circuit to directly output a large current when the solenoid coil is energized, all the components of the booster circuit must be increased in size (capacity increased). Therefore, in order to reduce the size of the entire booster circuit, an electrolytic capacitor is provided at the output of the booster circuit. This electrolytic capacitor accumulates the current output from the booster circuit and supplies the current to the solenoid coil when energized. By providing the electrolytic capacitor, it has been considered that the booster circuit does not need to directly output a large current and can charge the electrolytic capacitor with a small current consumption over a long period of time. That is, it has been thought that the booster circuit can efficiently charge the electrolytic capacitor.

Japanese Patent Laid-Open No. 10-306884 JP 2001-207498 A

  However, in actuality, when the voltage of the electrolytic capacitor drops due to energization of the solenoid coil, the booster circuit having the DUTY control function tries to charge the electrolytic capacitor with high DUTY. When the DUTY is high, the output capability of the booster circuit is increased, but the current loss is increased and the efficiency is deteriorated.

  On the other hand, when the DUTY of the booster circuit is fixed in a low state, the output capability of the booster circuit is also fixed, and it takes a long time to charge the electric field capacitor. In this case, the time required for the next valve operation becomes longer, and the operation performance (reaction speed) of the valve is lowered. That is, there is a possibility that the valve water discharge / water stop operation is delayed.

  Usually, the output of the booster circuit includes elements such as a microcomputer and a sensor that require a load current in addition to the switching of the valves. The load current required for these elements varies depending on the specifications and operating conditions of the valve device, and is difficult to predict. Therefore, if DUTY is fixed in a low state, when the load current becomes larger than expected, the voltage of the booster circuit may be excessively reduced, resulting in a system reset.

  Furthermore, the current drive capability of the booster circuit depends on the input voltage of the booster circuit. When the input voltage of the booster circuit becomes low due to battery exhaustion or insufficient power storage, the booster circuit originally secures a predetermined current driving capability by increasing DUTY. However, when DUTY is fixed low, the current drive capability of the booster circuit also decreases as the input voltage decreases. Therefore, it is dangerous to fix DUTY low for the purpose of high efficiency.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a valve device in which a booster circuit can efficiently perform a boosting operation without adversely affecting the reaction speed of the valve, and its It is to provide a driving method.

  The valve device according to claim 1 is an electromagnetic valve that is driven to open and close a flow path by energizing a solenoid coil, a booster that boosts a primary voltage from a power source to generate a secondary voltage, A drive capacitor that is charged by an output current from the boosting unit and supplies current to the solenoid coil when driving the solenoid valve, and is provided between the solenoid coil and the drive capacitor. A latching type valve device including an energization unit that starts or stops energization of the solenoid coil, and a control unit that controls the boosting unit and the energization unit, and is connected in parallel to the drive capacitor, An auxiliary capacitor that charges the drive capacitor during a period in which energization from the drive capacitor to the solenoid coil is stopped; And said that there were pictures. As a result, the auxiliary capacitor supplies charge to the drive capacitor during a predetermined period (during the first specified period) after the energization from the drive capacitor to the solenoid coil is stopped, and the boosting unit boosts the voltage. The output voltage of the drive capacitor can be increased without relying only on the operation. As a result, the boosting unit can perform a low-DUTY and highly efficient boosting operation without adversely affecting the reaction speed of the valve.

  According to a second aspect of the present invention, the valve device further includes a limiting resistor that is provided between the driving capacitor or the auxiliary capacitor and the boosting unit and limits an output current of the boosting unit. The limiting resistor suppresses the output of the boosting unit and promotes charge transfer from the auxiliary capacitor to the driving capacitor. Therefore, the output voltage of the drive capacitor can be brought closer to the threshold voltage necessary for driving the solenoid valve during the first specified period. As a result, the booster can perform a boosting operation with further low DUTY and high efficiency after the first specified period.

  According to a third aspect of the present invention, the valve device further includes a power generation unit that generates power using the fluid flowing through the flow path, and the boosting unit receives the primary voltage from the power generation unit. Thus, immediately after energizing the solenoid to open the solenoid valve and start discharging water, the boosting unit stops the boosting operation, or lowers the DUTY indicating the ratio of the on-time per unit time. Therefore, the current value output from the generator as the primary side voltage can be small, and the starting torque of the turbine of the power generation unit can be reduced. As a result, the water turbine of the power generation unit can easily rotate, and the influence on the water flow can be suppressed.

  5. The valve device according to claim 4, wherein the control unit limits the boosting operation of the boosting unit until a first specified period elapses after stopping energization of the solenoid coil, and the auxiliary capacitor is driven Charge the capacitor. As a result, the auxiliary capacitor can supply charges to the drive capacitor during the first specified period in which the boost operation of the boost unit is limited, and the output voltage of the drive capacitor can be increased. As a result, the boosting unit requires a small voltage for charging the drive capacitor after the first specified period, and can perform a low-DUTY and high-efficiency boosting operation.

  6. The valve device according to claim 5, wherein the control unit stops the boosting operation of the boosting unit until the first specified period elapses after the energization of the solenoid coil is stopped. During the first specified period when the boosting operation of the boosting unit is stopped, the auxiliary capacitor can supply electric charge to the driving capacitor, and the output voltage of the driving capacitor can be increased. As a result, the boosting unit can perform a low-DUTY and high-efficiency boosting operation after the first specified period.

  7. The valve device according to claim 6, wherein the boosting unit induces a current in the inductor by repeatedly turning on and off the inductor that induces a current from the power source, and drives the current induced in the inductor. A switching element to be supplied to a capacitor, wherein the control unit is a ratio of an on-time of the switching element in a unit time during the first specified period after the energization of the solenoid coil of the switching element is stopped. Is fixed regardless of the output voltage of the drive capacitor. As a result, not only the auxiliary capacitor but also the booster supplies electric charges to the drive capacitor during the first specified period, so that the output voltage of the drive capacitor is quickly recovered. As a result, the booster can recover the output voltage of the drive capacitor to the threshold voltage in a short time. As a result, it is possible to cope with unexpected load fluctuations without reducing the reaction speed of the valve.

  8. The valve device according to claim 7, wherein the boosting unit induces a current in the inductor by repeatedly turning on and off the inductor that induces a current from the power source, and drives the current induced in the inductor. A switching element to be supplied to the capacitor, and the control unit indicates a ratio of an on-time of the switching element in a unit time until the second specified period elapses after the first specified period elapses. The DUTY is fixed regardless of the output voltage of the driving capacitor. As a result, the auxiliary capacitor can supply charges to the drive capacitor during the first specified period when the boost operation of the boost unit is stopped, and the output voltage of the drive capacitor can be increased before the boost operation of the boost unit. Further, after the first specified period, during the second specified period, not only the auxiliary capacitor but also the booster supplies the charge to the drive capacitor, so that the output voltage of the drive capacitor is quickly recovered. As a result, the boosting unit can not only perform a low-DUTY and high-efficiency boosting operation, but can recover the output voltage of the driving capacitor to the threshold voltage in a short time. As a result, the booster can efficiently boost the output voltage of the drive capacitor. Further, it is possible to cope with unexpected load fluctuations without reducing the reaction speed of the valve.

  9. The valve device according to claim 8, wherein the driving capacitor is composed of an electrolytic capacitor, and the auxiliary capacitor is composed of an electric double layer capacitor. As a result, the auxiliary capacitor supplies electric charges to the drive capacitor during the first specified period, and the output voltage of the drive capacitor can be raised before the boosting operation of the boosting unit. As a result, the boosting unit can perform a low-DUTY and high-efficiency boosting operation after the first specified period.

  The valve device according to claim 9, wherein the auxiliary capacitor is larger in internal resistance and capacity than the driving capacitor. As a result, the auxiliary capacitor supplies electric charges to the drive capacitor during the first specified period, and the output voltage of the drive capacitor can be raised before the boosting operation of the boosting unit. As a result, the boosting unit can perform a low-DUTY and high-efficiency boosting operation after the first specified period.

  The driving method of the valve device according to claim 10 is connected to an electromagnetic valve driven to open and close the flow path by energizing the solenoid coil, a boosting unit that boosts a power supply voltage, and an output of the boosting unit. A driving method for a latching type valve device, comprising: a driving capacitor; an energization section provided between the solenoid coil and the driving capacitor; and an auxiliary capacitor connected in parallel to the driving capacitor. The energization unit connects the drive capacitor to the solenoid coil to energize the solenoid coil, and after the energization to the solenoid coil is stopped, the auxiliary capacitor charges the drive capacitor. Thereby, after energizing the solenoid coil from the drive capacitor, the auxiliary capacitor supplies electric charge to the drive capacitor, and the output voltage of the drive capacitor can be increased without depending on the output from the boosting unit. As a result, the boosting unit can perform a low-DUTY and highly efficient boosting operation without adversely affecting the reaction speed of the valve.

Sectional drawing which shows an example of the hand-washing machine using the automatic water tap according to 1st Embodiment which concerns on this invention. FIG. 3 is a cross-sectional view showing an example of the configuration of a latching type solenoid valve 23. The figure which shows an example of the circuit structure of the control unit 30 using a generator. The figure which shows an example of the circuit structure of the control unit 30 using a battery. The flowchart which shows operation | movement of the valve apparatus according to 1st Embodiment. The timing diagram which shows operation | movement of the valve apparatus by 1st Embodiment. The flowchart which shows operation | movement of the valve apparatus according to 2nd Embodiment which concerns on this invention. The timing diagram which shows operation | movement of the valve apparatus by 2nd Embodiment. The flowchart which shows operation | movement of the valve apparatus according to 3rd Embodiment which concerns on this invention. The timing diagram which shows operation | movement of the valve apparatus by 3rd Embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
FIG. 1 is a sectional view showing an example of a hand-washing basin using an automatic water faucet according to the first embodiment of the present invention. The hand wash basin according to the present embodiment includes a faucet fitting 14 mounted on the top plate 12 of the ball 10, a valve unit 16 as a valve device positioned below the top plate 12, and a battery 18 fixed to the wall surface. I have.

  The faucet fitting 14 includes a control unit 30 that controls human body detection and valve opening / closing. The control unit 30 is fixed to the faucet fitting 14 via the circuit board 31. The circuit board 31 is mounted with electronic devices such as a microcomputer, an LED (Light Emitting Diode), and a photodiode. The LED repeatedly emits infrared light through a window 28 opened toward the ball 10, and the photodiode detects infrared light reflected from the direction of the ball 10. If the hand of the user of the automatic water faucet exists in the direction of the ball 10, the reflected light of the infrared rays increases and the human body can be detected.

  When the photodiode detects a human body, the diaphragm valve 20 of the valve unit 16 opens between the primary side flow path 22 and the secondary side flow path 24 and discharges water from the water discharge fitting 26. When the photodiode is not detecting a human body, the diaphragm valve 20 closes the space between the primary side flow path 22 and the secondary side flow path 24 and stops water discharge from the water discharge fitting 26.

  FIG. 2 is a cross-sectional view showing an example of the configuration of a latching solenoid valve 23 (hereinafter simply referred to as valve 23). The valve 23 as an electromagnetic valve includes a diaphragm valve 20, a plunger 40, a permanent magnet 50 (hereinafter simply referred to as a magnet 50), a spring 52, a solenoid coil 54 (hereinafter simply referred to as a solenoid 54), and a cleaning pin 45. And a pressure chamber 48.

  Diaphragm valve 20 is configured to open and close between primary side flow path 22 and secondary side flow path 24. The plunger 40 is configured to open and close a pilot hole 47 provided in the diaphragm valve 20.

  A permanent magnet 50 (hereinafter simply referred to as magnet 50) attracts the plunger 40 to open the diaphragm valve 20. The spring 52 presses the plunger 40 toward the diaphragm valve 20 to close the diaphragm valve 20. The force that the magnet 50 attracts the plunger 40 and the force that the spring 52 pushes the plunger 40 are mutually repulsive. When the plunger 40 approaches the magnet 50, the force by the magnet 50 surpasses the force by the spring 52, and the diaphragm valve 20 is opened. On the other hand, when the plunger 40 is separated from the magnet 50, the force by the spring 52 overcomes the force by the magnet 50, and the diaphragm valve 20 is closed.

  The solenoid 54 receives power supply from the control unit 30 shown in FIG. 3 to generate a magnetic force, and moves the plunger 40 to switch between the open state and the closed state of the valve 23.

  As shown in FIG. 2, the plunger 40 closes the pilot hole 47 when the valve 23 is closed. At the same time, the plunger 40 positions the cleaning pin 45 so as to communicate between the primary flow path 22 and the pressure chamber 48 via the bleed hole 46. Accordingly, the pressure in the pressure chamber 48 is substantially equal to the pressure in the primary flow path 22 through the bleed hole 46. Since the pressure of the primary side flow path 22 which is the water supply side is higher than the pressure of the secondary flow path 24, the diaphragm valve 20 has a secondary pressure due to the pressure difference between the primary side flow path 22 and the secondary flow path 24. It is pressed against the opening of the flow path 24. Thus, the diaphragm valve 20 blocks between the primary side flow path 22 and the secondary flow path 24.

  In the closed state of the valve 23, the solenoid 40 is not energized, and the plunger 40 is fixed in a state where the pilot hole 47 is closed by the elastic force of the spring 52. Therefore, the diaphragm valve 20 maintains a closed state due to a pressure difference between the primary side flow path 22 and the secondary side flow path 24.

  When switching the valve 23 from the closed state to the open state, the control unit 30 energizes the solenoid 54 to move the plunger 40 toward the magnet 50. When the plunger 40 approaches the magnet, the magnet 50 attracts the plunger 40 with a stronger force than the spring 52. As a result, the plunger 40 opens the pilot hole 47. When the pilot hole 47 is opened, the fluid flows from the pressure chamber 48 to the secondary flow path 24, and the pressure in the pressure chamber 48 decreases. When the pressure in the pressure chamber 48 decreases, the pressure of the primary side flow path 22 causes the diaphragm valve 20 to open the opening of the secondary side flow path 24, and the primary side flow path 22 and the secondary side flow path 24. Communicate between the two. In this way, the valve 23 is opened.

  In the open state of the valve 23, the plunger 40 is attracted to the magnet 50 with a force stronger than that of the spring 52 due to the magnetic force of the magnet 50. Therefore, the plunger 40 is fixed in contact with the magnet 50 without energizing the solenoid 54.

  When switching the valve 23 from the open state to the closed state, the control unit 30 energizes the solenoid 54 in the direction opposite to that at the time of switching from the closed state to the open state. As a result, the plunger 40 is moved toward the diaphragm valve 20. When the plunger 40 closes the pilot hole 47, the diaphragm valve 20 is closed by the pressure difference between the primary side flow path 22 and the secondary side flow path 24 as described above.

  FIG. 3 is a diagram illustrating an example of a circuit configuration of the control unit 30 using the generator. The control unit 30 includes a microcomputer 101, a sensor 102, a solenoid energizing circuit 105 as an energizing unit, a storage capacitor 106, a boosting circuit 107 as a boosting unit, a power generation unit 108, a charging voltage limiting circuit 109, a limiter A resistor 114, a solenoid valve driving capacitor (hereinafter also simply referred to as a driving capacitor) 115, and an auxiliary capacitor 116 are provided.

  FIG. 4 is a diagram illustrating an example of a circuit configuration of the control unit 30 using a battery. The control unit 30 shown in FIG. 4 is different from the control unit 30 shown in FIG. 3 in that a battery is used instead of the generator, and the charging voltage limiting circuit 109 and the storage capacitor 106 are not included. Since the other configuration of the control unit 30 shown in FIG. 4 is the same as that shown in FIG. 3, the configuration will be described mainly with reference to FIG.

  The sensor 102 senses the human body of the user of the faucet device. The sensor 102 may be a manual operation switch or a timer as long as it is a control condition for the faucet device.

  A solenoid energization circuit 105 as an energization unit is provided between the solenoid 54 and the drive capacitor 115, and is configured to start or stop energization from the drive capacitor 115 to the solenoid 54. By energizing the solenoid 54, the plunger 40 shown in FIG. 2 is driven. As described above, the solenoid 54 is a coil that does not consume current except when the valve 23 is switched between open and closed states. The solenoid energization circuit 105 is an H bridge circuit that switches the direction of the current flowing through the solenoid 54 in accordance with the switching of the open / close state of the valve 23. As described above, the energizing current of the solenoid energizing circuit 105 is overwhelmingly larger than the current consumed by the microcomputer 101 and the sensor 102. For example, some products allow a current of about several hundred mA to flow through the solenoid when the valve is driven (when energized). On the other hand, when the open state or the closed state is maintained, the current consumed by the microcomputer and the sensor is about several mA.

  The booster circuit 107 is a switching regulator type DC-DC converter, and includes an inductor 171, a switching element 172, and a diode 173. The inductor 171 is connected to the storage capacitor 106, connected to the power generation unit 108 via the charging voltage limiting circuit 109, and connected to the driving capacitor 115 via the diode 173 and the limiting resistor 114. Alternatively, the inductor 171 is connected to the battery 10 instead of the storage capacitor 106. The switching element 172 is, for example, a transistor, and is connected between one end of the inductor 171 on the drive capacitor 115 side and the ground. The switching element 172 is on / off controlled under the control of the microcomputer 101.

  By turning on the transistor 172, the transistor 172 connects the output of the storage capacitor 106 to the ground via the inductor 171 and induces a current in the inductor 171. By turning off the transistor 172, the current induced in the inductor 171 is output to the drive capacitor 115 via the diode 173. As the transistor 172 is repeatedly turned on / off in this manner, the booster circuit 107 boosts the primary side voltage VC to the secondary side voltage VDD and charges the drive capacitor 115. The secondary side voltage VDD is also used as a power supply voltage applied to the sensor 102, the microcomputer 101, and the like.

In general, when the time during which the transistor 172 is on is ON and the time during which the transistor 172 is OFF is OFF, the ON / (ON + OFF) ratio is called DUTY (or ON-DUTY). In a general booster circuit DUTY control method, the microcomputer 101 controls the booster circuit DUTY in accordance with the load state of the booster circuit. When DUTY is high, the on-time of the transistor 172 is long, so that the booster circuit can store a large amount of current in the inductor 171. Therefore, the output capability itself of the booster circuit is high. However, since the off time of the transistor 172 becomes short, the booster circuit turns on the transistor again without fully discharging the current accumulated in the inductor 171 to the output side. Therefore, the current that does not contribute to the boosting operation in the current consumption in the boosting circuit increases, and the efficiency of the boosting circuit is deteriorated. Here, the efficiency of the booster circuit is the ratio of the power input to the booster circuit per unit time and the output power.
On the other hand, when DUTY is low, the off-time of the transistor becomes long, so that the booster circuit can completely discharge the current accumulated in the inductor 171 to the output side. Therefore, there is no current not involved in the boosting operation, and the efficiency of the boosting circuit is good. However, if the on-time of the transistor is too short, the booster circuit turns off the transistor before accumulating sufficient current in the inductor 171. Therefore, the output capability of the booster circuit is lowered. Thus, when the booster circuit 107 is controlled by DUTY, the efficiency with the output capability of the booster circuit 107 is in a trade-off relationship.
The power generation unit 108 may be a hydraulic power generator that is provided in a water channel and generates power using water flowing through the water channel. The electric power generated by the power generation unit 108 charges the storage capacitor 106 via the charging voltage limiting circuit 109. Unlike a secondary battery that chemically reacts, the storage capacitor 106 does not deteriorate due to repeated charge and discharge and has a long life. The battery 18 functions as a backup power source for the power generation unit 108. The charging voltage limiting circuit 109 limits the output voltage of the power generation unit 108 to a predetermined voltage or less in order to protect the microcomputer 101 and the like.

  When a hydroelectric generator is used as a power source, the hydroelectric generator is installed in the water channel of the valve device, and power is generated using the fluid flowing through the valve device. A valve device using a hydroelectric generator is preferable in that it can reduce wasted water by electrical control compared to manual operation, and it is environmentally friendly because it generates operating power itself. The valve device using such a hydroelectric generator stores the generated power in the storage capacitor 106. However, as described above, since the output voltage from the storage capacitor 106 varies depending on the amount of storage, the booster circuit 107 supplies a stable voltage to the drive capacitor 115, the microcomputer 101, and the like. On the other hand, when the battery 18 is used as a power source as shown in FIG. 4, it is preferable that the number of batteries is small in terms of downsizing the valve device, replacing the battery, and reducing costs. When the number of batteries is small, the power supply voltage becomes low, so that the booster circuit 107 boosts the power supply voltage from the battery.

  As a voltage conversion circuit other than the switching booster circuit, a switching step-down circuit, a drop type voltage conversion circuit, a switched capacitor, or the like can be considered. However, in the switching step-down circuit, the power supply on the input side needs to be a high voltage, and the number of storage capacitors or the number of batteries must be increased. Further, the drop type voltage conversion circuit has a low efficiency because the voltage drop is directly lost. Furthermore, the output of the switched capacitor is small. For these reasons, the switching booster circuit is suitable for the efficient generation of the high voltage necessary for driving the valve 23.

  The microcomputer 101 as a control unit controls the DUTY of the booster circuit 107 and the energization state of the solenoid energization circuit 105 based on the target value of the voltage VC before boosting and the supply voltage VLS supplied to the solenoid 54. For example, when switching the valve 23 from the closed state to the open state, the microcomputer 101 turns on the transistors connected to the ports P01 and P03, thereby causing a current to flow in the direction of the arrow A1. On the other hand, when switching the valve 23 from the open state to the closed state, the microcomputer 101 turns on the transistors connected to the ports P02 and P04, thereby causing a current to flow in the direction of the arrow A2.

  The solenoid valve driving capacitor 115 is an electrolytic capacitor connected between the node N1 and the ground. The node N1 is a connection node between the booster circuit 107 and the solenoid energization circuit 105. The drive capacitor 115 is charged by the current output from the booster circuit 107 and supplies current to the solenoid energization circuit 105 when the solenoid 54 is energized. VLS is a voltage output from the drive capacitor 115 to the solenoid energization circuit 105.

  The auxiliary capacitor 116 is, for example, an electric double layer capacitor connected in parallel to the drive capacitor 115. The auxiliary capacitor 116 is provided to charge the drive capacitor 115 during the period when the solenoid energization circuit 105 stops energization from the drive capacitor 115 to the solenoid 54. The electric double layer capacitor applied to the auxiliary capacitor 116 is generally a capacitor having a very large internal resistance (for example, 10 times or more) than the electrolytic capacitor, although the internal resistance is much larger than that of the electrolytic capacitor.

  Since the electric double layer capacitor has a large internal resistance, it takes longer to charge and discharge than the electrolytic capacitor. Therefore, when an electric double layer capacitor is used as the auxiliary capacitor 116, the auxiliary capacitor 116 supplies almost no current when the solenoid 54 is energized, and the drive capacitor 115 made of an electrolytic capacitor supplies current to the solenoid 54. At this time, the output voltage of drive capacitor 115 (voltage VLS at node N1) temporarily decreases.

  On the other hand, the capacity of the auxiliary capacitor 116 is much larger than that of the driving capacitor 115, and a large amount of electric charge is accumulated therein. Therefore, the auxiliary capacitor 116 can supply electric charge to the driving capacitor 115 after the energization of the solenoid 54 is completed. As a result, the auxiliary capacitor 116 can raise (recover) the voltage VLS of the node N <b> 1 that has temporarily decreased to some extent. However, since the discharge of the auxiliary capacitor 116 takes some time, the microcomputer 101 stops the operation of the booster circuit 107 for a predetermined period after the energization of the solenoid 54 is completed, or the booster circuit 107 is lowered. Operate with DUTY.

The internal resistance (ESR (Equivalent Series Resistance)) and capacity of the auxiliary capacitor 116 are parameters to be set by other factors such as the internal resistance (ESR) and capacity of the driving capacitor 115, and the resistance (ESR) of the solenoid 54. . For this reason, the preferred internal resistance (ESR) and capacity of the auxiliary capacitor 116 are individually determined by the configuration of the valve 23. However, at least the internal resistance and capacitance of the auxiliary capacitor 116 are larger than the internal resistance and capacitance of the driving capacitor 115, respectively. This is because the drive capacitor 115 plays a role of supplying an energization current to the solenoid 54, and the auxiliary capacitor 116 is configured to hold an internal charge while the solenoid 54 is energized. The internal resistance of the auxiliary capacitor 116 is larger than the resistance (ESR) of the solenoid 54. This is also for suppressing energization from the auxiliary capacitor 116 to the solenoid 54 and holding the internal charge. Further, the period during which the operation of the booster circuit 107 is stopped or the period during which DUTY is lowered is a period during which sufficient charge transfer is performed from the auxiliary capacitor 116 to the drive capacitor 115, and the time constant of the path of the charge transfer is about Is appropriate. The time constant of the charge transfer path is a value obtained by connecting the internal resistance and the capacitance of each of the auxiliary capacitor 116 and the driving capacitor 115 in series. However, since the auxiliary capacitor 116 is considerably larger, the internal resistance of the auxiliary capacitor 116 and What is necessary is just to set according to capacity.
After elapse of the predetermined period, the microcomputer 101 determines the DUTY of the booster circuit 107 based on the value of the voltage VLS as usual. At this time, since the voltage VLS has recovered to some extent, the booster circuit 107 does not need to operate at a high DUTY, and only needs to operate at a relatively low DUTY. When viewed as a load of the booster circuit 107, the auxiliary capacitor 116 and the drive capacitor 115 are in parallel. Since the internal resistance of the auxiliary capacitor 116 is larger than that of the driving capacitor 115, the driving capacitor 115 and the auxiliary capacitor 116 are slowly charged with a slow time constant that depends on the internal resistance of the auxiliary capacitor 116. As a result, the booster circuit 107 can charge the drive capacitor 115 and the auxiliary capacitor 116 over a long time with a relatively low DUTY. That is, the booster circuit 107 can charge the drive capacitor 115 and the auxiliary capacitor 116 with high efficiency.
The auxiliary capacitor 116 may be provided between the drive capacitor 115 and the solenoid energization circuit 105, or may be provided between the drive capacitor 115 and the limiting resistor 114. In both cases, the circuit operation is the same.

  The limiting resistor 114 is provided between the booster circuit 107 and the driving capacitor 115 (or the auxiliary capacitor 116). Conventionally, the limiting resistor 114 has been provided to compensate for the insufficient output capability of the booster circuit 107. In general, a resistor that enters between the power source (in this case, the booster circuit 107) and the load (in this case, the driving capacitor 115) prevents an excessive load current from flowing from the power source. In the present embodiment, the limiting resistor 114 is provided to increase the impedance between the output of the booster circuit 107 and the drive capacitor 115 and to promote charge transfer from the auxiliary capacitor 116 to the drive capacitor 115. Further, when the output voltage VLS of the drive capacitor 115 is restored to a predetermined voltage and charging by the booster circuit 107 is performed, the limiting resistor 114 can reduce the output current from the booster circuit 107. Therefore, when the output voltage VLS is maintained at a predetermined threshold voltage close to the boost target voltage, the DUTY of the booster circuit 107 may be low. By making DUTY low, the booster circuit 107 can boost the drive capacitor 115 and the auxiliary capacitor 116 with high efficiency.

  FIG. 5 is a flowchart showing the operation of the valve device according to the first embodiment. The routine shown in FIG. 5 is repeatedly executed after power-on so that water discharge starts without delay when a human body is sensed and water stops without delay when the human body is no longer sensed.

  After the power is turned on, first, the battery 18 shown in FIG. 3 or the battery 10 shown in FIG. 4 supplies power to each element in the control unit 30. Thereby, the booster circuit 107 starts a boosting operation (S100). Initially, voltage VLS is in a very low state, so that booster circuit 107 charges drive capacitor 115 and auxiliary capacitor 116 with a high DUTY. Then, the microcomputer 101 starts driving the sensor 102 (S110).

  When the voltage VLS reaches a predetermined threshold voltage (for example, 5 V), the microcomputer 101 decreases the DUTY of the booster circuit 107 or stops the boost operation of the booster circuit 107. The output voltage VLS of the driving capacitor 115 is also lowered by driving the microcomputer 101 and the sensor 102 other than the booster circuit 107. Therefore, in this case, the microcomputer 101 increases the DUTY of the booster circuit 107 or starts the boost operation of the booster circuit 107. In other words, the microcomputer 101 maintains the output voltage VLS at a predetermined threshold voltage by driving the booster circuit 107 with DUTY corresponding to the voltage VLS or by stopping it. Hereinafter, the state in which the valve 23 is maintained in the closed state or the open state and the solenoid 54 is energized is called an energization standby state.

  When the sensor 102 does not detect a human body (NO in S120), the microcomputer 101 determines whether or not the water is stopped. When the human body is not sensed in the previous routine or in the first routine, the valve 23 is already in the water stop state (YES in S130). Therefore, since the switching of the valve 23 is unnecessary, the microcomputer 101 does not perform the energization process, and the microcomputer 101 performs a predetermined first specified period after the previous energization of the solenoid 54 (execution of the open energization process or the close energization process). It is determined whether (for example, 0.5 seconds) has elapsed (S170). This determination can be made by executing a time measurement after a timer built in the microcomputer 101 is energized. The first specified period may be stored in advance in a storage unit (RAM or ROM) in the microcomputer 101.

  If the first specified period has elapsed since the previous energization (NO in S170), or if it is the first routine, the process returns to step S100. Therefore, the booster circuit 107 repeats the boosting operation as necessary to maintain the voltage VLS at the threshold voltage, and the sensor 102 continues the detection operation.

  In such an energization standby state, the microcomputer 101 and the sensor 102 consume current, but since the current consumption is much smaller than the current energized to the solenoid 54, the decrease in the voltage VLS is small. Therefore, the DUTY of the booster circuit 107 in the energization standby state may be low. Since DUTY is low, the booster circuit 107 can efficiently maintain the output voltage VLS at a threshold voltage (for example, 5 V) that is a boost target.

  On the other hand, when it is in the water discharge state in step S130 (NO in S130), a closing energization process is performed (S140). The closing energization process is a process of switching the valve 23 from the open state to the closed state. At this time, the electric charge of the driving capacitor 115 is used for energizing the solenoid 54, and the electric charge of the auxiliary capacitor 116 is almost retained. Judgment whether or not it is still water is performed as follows. The RAM in the microcomputer 101 stores the history of the output ports P01 to P04 involved in energizing the solenoid 54. The history shows the current open / closed state of the valve 23. Thereby, water discharge is stopped.

  After the closing energization process, the timer in the microcomputer 101 starts measuring time (S145). If the first specified period (0.5 seconds) has not elapsed after the closing energization process (YES in S170), the microcomputer 101 stops the boosting operation of the booster circuit 107 (S180). Then, steps S110 to S170 are executed again. Steps S110 to S180 are repeatedly executed until it is determined in step S170 that the first specified period has elapsed after the closing energization process or a new energization process is performed. That is, the microcomputer 101 performs the boosting operation of the booster circuit 107 until the first specified period (for example, 0.5 seconds) elapses after the closing energization process or until the time measurement is interrupted by a new energization process. Stop. During the first specified period, the auxiliary capacitor 116 supplies charge to the drive capacitor 115. As a result, the output voltage VLS rises toward the threshold voltage. Hereinafter, in the first embodiment, the first specified period is referred to as a boost stop period.

The boost stop period can be set to a time of about a time constant determined from the internal resistance and capacitance of the auxiliary capacitor 116. More preferably, the boost stop period is continued until the transfer of charge from the auxiliary capacitor 116 to the drive capacitor 115 is completed and the output voltage of the auxiliary capacitor 116 and the output voltage of the drive capacitor 115 become equal. However, if the boost stop period is too long, boosting of the output voltage VLS may not be in time for the next energization process. Therefore, the boost stop period is set in consideration of the internal resistance and capacity of the auxiliary capacitor 116, the valve reaction speed, and the like. In this case, before the output voltage of the auxiliary capacitor 116 becomes equal to the output voltage of the drive capacitor 115 (that is, during the recovery of the output voltage VLS), the booster circuit 107 may start to operate. However, even in this case, the auxiliary capacitor 116 can raise the voltage VLS to some extent. Further, immediately after energization, the voltage VLS is in a very low state, so that the internal charge of the auxiliary capacitor 116 is rapidly drawn by the voltage difference between the internal voltage and the voltage VLS, and the current VLS is increased in a short time. be able to. Therefore, the boost stop period may be set short in consideration of the next energization process. That is, in this embodiment, the boost stop period can be set short so as not to affect the reaction speed of the valve device.
If the boost stop period has elapsed after completion of the closing energization process (NO in S170), the process returns to step S100. That is, the microcomputer 101 starts the boosting operation of the booster circuit 107. At this time, the microcomputer 101 drives the booster circuit 107 with DUTY corresponding to the voltage VLS.

  When the sensor 102 detects a human body in step S120 (YES in S120), the microcomputer 101 determines whether or not the water is being discharged (S150). When a human body is detected in the previous routine and the valve 23 is already in a water discharge state (YES in S150), switching of the valve 23 is not necessary. Therefore, without performing the energization process, the microcomputer 101 determines whether or not a boost stop period (for example, 0.5 seconds) has elapsed since the previous energization (S170). If the boost stop period has elapsed since the previous energization (NO in S170), the process returns to step S100. That is, the valve 23 maintains the energization standby state. At this time, since the sensor 102 continues to sense the human body, the valve device continues to discharge water.

  If the water is stopped (NO in S150), an open energization process is performed (S160). The open energization process is a process of switching the valve 23 from the closed state to the open state. Thereby, water discharge is started. The determination of whether or not the water is discharged is performed in the same manner as the determination of whether or not the water is stopped.

  After the opening energization process, the timer of the microcomputer 101 starts measuring time (S165). Thereafter, step S170 is executed as described above, and the process returns to step S100. Alternatively, S170 and S180 are executed, and the process returns to S110. That is, the microcomputer 101 stops the boosting operation of the booster circuit 107 until the boost stop period elapses after the open energization process or until the time measurement is interrupted by a new energization process. In this embodiment, since the booster circuit 107 is stopped during the boost stop period after the energization process is completed, the auxiliary capacitor 116 supplies the drive capacitor 115 with electric charges. As a result, the output voltage VLS rises to some extent toward the threshold voltage in the energization standby state.

  Note that when a new energization process intervenes during the boost stop period (S140 or S160), the timing of the timer in the microcomputer 101 is interrupted. Then, the timer starts counting again after the newly generated energization process (S145 or S165). Subsequent processing is the same as the processing described above.

  FIG. 6 is a timing chart showing the operation of the valve device according to the first embodiment. Initially (t0 to t1), the sensor 102 is not sensing a human body and is in a power-on standby state. At this time, the solenoid 54 is not energized, and the valve 23 is kept closed. The sensor 102 starts the water discharge without delay when the human body is sensed, and repeats the detection operation so as to stop the water without delay when the human body is no longer sensed (for example, every 0.5 seconds). The energization standby state from t0 to t1 is a state in which a loop composed of YES in S100 to S130 and NO in S170 in FIG. 5 is repeatedly executed.

  When the sensor 102 detects a human body at t1, the solenoid 54 is energized, and the valve device executes an open energization process (FIG. 5, YES to S160 in S120).

  After the opening energization process is executed, the booster circuit 107 stops at t2 (S180 in FIG. 5). After the energization processing, a timer in the microcomputer 101 measures time for a predetermined boost stop period (for example, 0.5 seconds). During the boost stop period, the auxiliary capacitor 116 supplies electric charge to the drive capacitor 115. As a result, the voltage VLS increases. If the driving cycle of the sensor 102 is shorter than the boost stop period, the loop consisting of S110 to S120 YES, S150 YES, S170 YES and S180 in FIG. 5 is repeatedly executed during the boost stop period.

  After the elapse of the boosting stop period, at t3, the booster circuit 107 starts the boosting operation (FIG. 5, NO in S170). Since the voltage VLS has risen to some extent at this time, the booster circuit 107 can efficiently boost the voltage VLS to a predetermined threshold voltage (for example, 5 V) with low DUTY.

  When the voltage VLS reaches the threshold voltage at t4, the valve device is again in the energization standby state. The energization standby state from t4 to t5 is a state in which a loop composed of YES in S100 to S120, YES in S150, and NO in S170 in FIG. 5 is repeatedly executed. In addition, after the opening voltage process is executed, from t2 to t5, the sensor 102 continues to sense the human body, and the valve device continues to discharge water.

  When the sensor 102 no longer senses a human body at t5, the valve device executes a closing energization process (S140 in FIG. 5). In the closing energization process, the energization direction to the solenoid 54 is opposite to that in the opening energization process, but the operation of the booster circuit 107 in other closing energization processes is the same as that in the open energization process. That is, the boosting operation from t6 to t8 is the same as the boosting operation from t1 to t4.

  As described above, the valve device according to the present embodiment temporarily stops the boosting operation of the booster circuit 107 after the energization process to the solenoid 54. During the boost stop period, the auxiliary capacitor 116 supplies electric charge to the drive capacitor 115, and increases the voltage VLS before the boost operation.

  If the booster circuit 107 is operated immediately after the energization process, the voltage VLS drops to a very low level immediately after the close energization process. For this reason, the booster circuit 107 must execute a boosting operation for a long period of time with a high DUTY. When the DUTY is high, the efficiency of the boosting operation of the booster circuit 107 is deteriorated, leading to a waste of power consumption by the booster circuit 107.

  On the other hand, in the valve device according to the present embodiment, since the output voltage VLS at the time of resuming the boosting operation increases toward the threshold voltage during energization standby, the charge that the booster circuit 107 charges the drive capacitor 115 is charged. Is less. Therefore, the booster circuit 107 only needs to perform a boosting operation with a relatively low DUTY, and wasteful power consumption can be suppressed. In addition, the valve device according to the present embodiment can perform the boosting operation with high efficiency without affecting the reaction speed of the valve device by appropriately setting the boost stop period of the booster circuit 107.

  The limiting resistor 114 in this embodiment suppresses the output of the booster circuit 107 and promotes charge transfer from the auxiliary capacitor 116 to the drive capacitor 115. Therefore, by providing the limiting resistor 114, the voltage VLS can be made closer to the threshold voltage during the boost stop period using the auxiliary capacitor 116 as a main power source. Further, when the output voltage VLS is restored to the threshold voltage, the limiting resistor 114 can reduce the output current from the booster circuit 107, so that the DUTY of the booster circuit 107 can be further reduced.

  Furthermore, in the present embodiment, the starting torque of the water turbine of the power generation unit 108 shown in FIG. 3 can be reduced by stopping the boosting operation immediately after the opening energization process. That is, since the step-up circuit 107 does not exist as an electrical load of the power generation unit 108, the load current of the power generation unit 108 decreases, the force that prevents the power generation unit 108 from rotating decreases, the water turbine easily rotates, and the water current flows. The effect that the influence which it gives can be suppressed is also acquired.

(Second Embodiment)
FIG. 7 is a flowchart showing the operation of the valve device according to the second embodiment of the present invention. The configuration of the valve device according to the second embodiment may be the same as the configuration of the valve device according to the first embodiment.

In the second embodiment, the microcomputer 101 sets the DUTY of the booster circuit 107 according to the voltage VLS for a first specified period (for example, 0.5 seconds) after the energization process. Is fixed in a lower state (S280). When setting DUTY in accordance with the value of voltage VLS, in the conventional general control method, when voltage VLS is low, priority is given to output capability over efficiency, and DUTY is increased to increase boost capability. On the other hand, when the voltage VLS is high, high output is unnecessary, so the efficiency is emphasized and the DUTY is lowered.
For example, it is common to select 50% or 75% for DUTY depending on whether or not the voltage VLS exceeds a certain threshold voltage. However, in the second embodiment, the DUTY of the booster circuit 107 is 25% in the first specified period. As described above, in the first specified period, the microcomputer 101 fixes the DUTY of the booster circuit 107 to a value lower than the DUTY depending on the voltage VLS. Hereinafter, in the second embodiment, the first specified period is referred to as a low DUTY period.

  The other operations in steps S100 to S170 are the same as the operations in steps S100 to S170 shown in FIG. Therefore, if the low DUTY period has not elapsed after the energization process (YES in S170), the microcomputer 101 performs the boosting operation in a state where the DUTY of the booster circuit 107 is fixed to 25% (S280 and S100). If the low DUTY period has elapsed after the energization process (NO in S170), the microcomputer 101 returns the DUTY of the booster circuit 107 to the DUTY depending on the voltage VLS (S100).

Note that DUTY in the low DUTY period is set to a value lower than DUTY depending on the voltage VLS.
FIG. 8 is a timing chart showing the operation of the valve device according to the second embodiment. The energization standby state at t0 to t11 is the same as the energization standby state at t0 to t1 shown in FIG. Moreover, the opening voltage process in t11-t12 is the same as the opening voltage process in t1-t2 shown in FIG.

  After execution of the opening energization process, from t12 to t13, the microcomputer 101 reduces the DUTY of the booster circuit 107 to 25% (S280 in FIG. 7). At this time, since the DUTY of the booster circuit 107 is fixed low, the booster circuit 107 charges the drive capacitor 115 efficiently. At the same time, the auxiliary capacitor 116 supplies electric charges to the driving capacitor 115. Therefore, in the second embodiment, since the charge is supplied from both the booster circuit 107 and the auxiliary capacitor 116 to the drive capacitor 115, the voltage VLS is quickly recovered. However, the efficiency of the booster circuit 107 during this period is high.

  Thereafter, the operation from t13 to t15 is the same as the operation from t3 to t5 shown in FIG. Moreover, the operation | movement of t15-t18 is operation | movement of a closing electricity supply process. Accordingly, in the operation from t15 to t18, the energization direction to the solenoid 54 is opposite to that in the open energization process t11 to t14, but the operation of the booster circuit 107 in the other energization processes is the same as that in the open energization process. It is. That is, the boosting operation from t15 to t18 is the same as the boosting operation from t11 to t14.

  In the second embodiment, not only the auxiliary capacitor 116 but also the booster circuit 107 supplies electric charges to the drive capacitor 115 after the energization process. Therefore, the recovery of the voltage VLS is quick. As a result, the booster circuit 107 can recover the voltage VLS to the threshold voltage in a short time. This means that it is possible to cope with unexpected load fluctuations without reducing the reaction speed of the valve. Note that boosting within a range where efficiency is not lowered at low DUTY does not adversely affect the efficiency of the layer pressure circuit 107. Rather, boosting in a range where efficiency is not lowered at low DUTY can shorten the charging time.

  Further, depending on the type of the valve device, the current supplied to the solenoid 54 when the valve is switched between open and closed may be smaller than the output capability of the booster circuit 107. In such a case, it is not always necessary to completely stop the booster circuit 107 after the energization process. This is because the booster circuit 107 can recover the voltage VLS efficiently and in a short time by charging the drive capacitor 115 with low DUTY. The second embodiment is advantageous when the current supplied to the solenoid 54 is small as described above.

  Furthermore, in the second embodiment, the starting torque of the water turbine of the power generation unit 108 shown in FIG. 3 is reduced by reducing the DUTY of the booster circuit 107 immediately after the opening energization process. In other words, the water wheel of the power generation unit 108 can easily rotate, and the effect of not affecting the water flow can be obtained.

  Since the second embodiment includes the auxiliary capacitor 116 as in the first embodiment, the effects of the first embodiment can also be obtained.

(Third embodiment)
FIG. 9 is a flowchart showing the operation of the valve device according to the third embodiment of the present invention. The configuration of the valve device according to the third embodiment may be the same as the configuration of the valve device according to the first embodiment.

  In the third embodiment, the microcomputer 101 stops the booster circuit 107 until a predetermined first specified period (for example, 0.5 seconds) elapses after the energization process (YES in S170). (S180). The operation of the valve device in the first specified period corresponds to that in the boost stop period of the first embodiment. Further, after the energization process, until a predetermined second specified period (for example, 2 seconds) elapses (NO in S170 and YES in S375), the microcomputer 101 depends on the voltage VLS for the DUTY of the booster circuit 107. The value is fixed to a value lower than the DUTY (S380). For example, in the third embodiment, the microcomputer 101 sets the DUTY of the booster circuit 107 to 25%. The operation of the valve device in the second specified period corresponds to the operation in the low DUTY period of the second embodiment. When the second specified period has elapsed after the energization process (NO in S375), the microcomputer 101 returns the DUTY of the booster circuit 107 to the DUTY depending on the voltage VLS (S100). Therefore, the third embodiment may be said to be a combination of the first and second embodiments.

In this manner, the booster circuit 107 transitions from the operation stop state to the low DUTY state, and further from the low DUTY state to the DUTY state depending on the voltage VLS. In general, the DUTY depending on the voltage VLS may be set high when the voltage VLS is low and conversely set low when the voltage VLS is high. For example, DUTY depending on the voltage VLS may be in a relationship inversely proportional to the voltage VLS, or may be changed in several steps according to the voltage VLS.
The other operations in steps S100 to S170 are the same as the operations in steps S100 to S170 shown in FIG. Therefore, the detailed description is abbreviate | omitted.

  FIG. 10 is a timing chart showing the operation of the valve device according to the third embodiment. The energization standby state at t0 to t21 is the same as the energization standby state at t0 to t1 shown in FIG. Moreover, the opening voltage process in t21-t22 is the same as the opening voltage process in t1-t2 shown in FIG.

  After execution of the opening energization process, the microcomputer 101 stops the boosting operation of the booster circuit 107 in the first specified period from t22 to t23 (YES in S170 and S180 in FIG. 9). At this time, the auxiliary capacitor 116 supplies electric charge to the drive capacitor 115 as in the operation in step S180 of the first embodiment.

  After the first specified period, in the second specified period from t23 to t24, the microcomputer 101 fixes DUTY of the booster circuit 107 to 25% (NO in S170, YES in S375, and S380 in FIG. 9). At this time, since the DUTY of the booster circuit 107 is lower than the DUTY depending on the voltage VLS, the drive capacitor 115 is efficiently charged. Further, since the DUTY of the booster circuit 107 is low, the auxiliary capacitor 116 continues to supply charges to the drive capacitor 115.

  Thereafter, the operation from t24 to t26 is the same as the operation from t3 to t5 shown in FIG. Moreover, the operation | movement of t26-t29 is an operation | movement of a closing electricity supply process. Therefore, in the operation from t26 to t29, the energization direction to the solenoid 54 is opposite to that in the open energization process t21 to t25, but the operation of the booster circuit 107 in the other energization processes is the same as that in the open energization process. It is. That is, the boosting operation from t26 to t29 is the same as the boosting operation from t21 to t25.

  In the third embodiment, the booster circuit 107 is stopped during the first specified period immediately after the energization process. In the first specified period, the auxiliary capacitor 116 supplies electric charge to the driving capacitor 115. Thus, at this stage, there is no charge that the booster circuit 107 charges the drive capacitor 115. In this respect, the third embodiment can obtain the same effects as those of the first embodiment.

  Thereafter, in the second specified period, the booster circuit 107 charges the drive capacitor 115 with low DUTY. Therefore, the third embodiment can also obtain the effects of the second embodiment.

  As described above, in the third embodiment, the step-up circuit 107 is changed from the operation stop state to the low DUTY state, and further from the low DUTY state to the high DUTY state in a stepwise manner. The effect of form can be obtained.

  The valve device according to the first to third embodiments can be used not only for automatic faucets but also for urinal washing.

  Even if the auxiliary capacitor 116 is provided as in the valve device according to the first to third embodiments, the output voltage VLS gradually decreases when the energization of the solenoid 54 is repeated in a short cycle. It is possible. In this case, it is necessary to increase the output capability of the booster circuit 107, DUTY increases, and efficiency decreases. However, in a long period (for example, one day), the period in which the solenoid 54 is not energized is longer than the energization period, that is, the water stop period in which the faucet is not used is longer than the water discharge period in which the faucet is used. it is obvious. Therefore, it is understood that the load current from the booster circuit 107 can be averaged by adding the auxiliary capacitor 116 in consideration of the operation frequency of the valve device over a long period of time. By averaging the load current from the booster circuit 107, the load of the booster circuit 107 is dispersed in time, the situation where the output of the booster circuit 107 becomes a large current is reduced, and the operation can be performed with low current and high efficiency. it can.

16 ... Valve unit (valve device)
23 ... Solenoid valve (solenoid valve)
54 ... Solenoid coil 101 ... Microcomputer (control unit)
105 ... Solenoid energization circuit (energization section)
107: Boosting unit 108: Power generation unit 114 ... Limiting resistor 115 ... Driving capacitor 116 ... Auxiliary capacitor 171 ... Inductor 172 ... Switching element 173 ... Diode

Claims (10)

A solenoid valve driven to open and close the flow path by energizing the solenoid coil;
A booster that boosts a primary side voltage from a power source to generate a secondary side voltage;
A driving capacitor that is charged by an output current from the boosting unit and supplies a current to the solenoid coil when driving the solenoid valve;
An energization unit that is provided between the solenoid coil and the drive capacitor, and starts or stops energization from the drive capacitor to the solenoid coil;
A latching type valve device comprising a control unit for controlling the boosting unit and the energization unit,
A valve device further comprising an auxiliary capacitor connected in parallel to the drive capacitor and charging the drive capacitor during a period in which energization from the drive capacitor to the solenoid coil is stopped.   2. The valve device according to claim 1, further comprising a limiting resistor provided between the driving capacitor or the auxiliary capacitor and the boosting unit to limit an output current of the boosting unit. Further comprising a power generation unit that generates electric power by the fluid flowing through the flow path,
The valve device according to claim 1, wherein the boosting unit receives the primary voltage from the power generation unit.   The control unit limits the boosting operation of the boosting unit until a first specified period elapses after stopping energization of the solenoid coil, and the auxiliary capacitor charges the drive capacitor. The valve device according to any one of claims 1 to 3.   5. The valve device according to claim 4, wherein the control unit stops the boosting operation of the boosting unit until the first specified period elapses after the energization of the solenoid coil is stopped. The boosting unit includes an inductor that induces a current from the power supply, and a switching element that induces a current in the inductor by repeatedly turning on and off, and supplies the current induced in the inductor to the driving capacitor. ,
The control unit outputs DUTY indicating a ratio of on-time of the switching element per unit time during the first specified period after stopping the energization of the solenoid coil of the switching element. The valve device according to claim 4, wherein the valve device is fixed regardless of the voltage. The boosting unit includes an inductor that induces a current from the power supply, and a switching element that induces a current in the inductor by repeatedly turning on and off, and supplies the current induced in the inductor to the driving capacitor. ,
The control unit sets, as an output voltage of the drive capacitor, DUTY indicating a ratio of an on-time of the switching element in a unit time until the second specified period elapses after the first specified period elapses. 6. The valve device according to claim 5, wherein the valve device is fixed regardless. The drive capacitor comprises an electrolytic capacitor;
The valve device according to any one of claims 1 to 7, wherein the auxiliary capacitor includes an electric double layer capacitor.   The valve device according to any one of claims 1 to 8, wherein the auxiliary capacitor is larger in internal resistance and capacity than the driving capacitor. A solenoid valve driven to open and close the flow path by energizing the solenoid coil; a booster that boosts a power supply voltage; a drive capacitor connected to the output of the booster; the solenoid coil and the drive capacitor; A driving method of a latching type valve device comprising an energization section provided between the auxiliary capacitor connected in parallel to the drive capacitor,
The energization unit connects the drive capacitor to the solenoid coil to energize the solenoid coil,
A method for driving a valve device, wherein the auxiliary capacitor charges the drive capacitor after energization of the solenoid coil is stopped.

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