JP3148252U - Latch solenoid valve with drive circuit - Google Patents

Abstract

An inexpensive latching electromagnetic that can be used in the same manner as a normal electromagnetic valve by adding a drive circuit that opens / closes the electromagnetic valve by detecting ON / OFF of a power supply voltage without using a microcomputer. Provide a valve. In a latch-type solenoid valve that controls the flow of fluid, an energization circuit that reverses the voltage applied to the solenoid in a forward and reverse direction is composed of three transistors and one diode. A cheaper IC timer than a microcomputer was used, and a drive circuit using a Zener diode and a transistor was attached to detect the power supply voltage OFF. [Selection] Figure 3

Description

  The present invention relates to an electromagnetic valve that controls a fluid by operating a valve body by electromagnetic force, and more particularly to a 1-coil latching electromagnetic valve that requires electric power only when the valve body is driven during opening and closing.

  Solenoid valves are widely used as valves for controlling the flow rate of fluid. Solenoid valves are used as flow path switching valves and directional control valves because of their high response speed.

  Among solenoid valves, latch solenoid valves only consume power instantaneously when switching between open / close operations, and ordinary solenoid valves require power to maintain an open or closed state. On the other hand, the latch type solenoid valve has an advantage of not requiring electric power. Because of these advantages, it is generally used frequently, and other uses such as a home fuel cell system have been tried.

  However, in order to control a single-coil latching solenoid valve with a single power supply, a drive circuit is required that applies a positive voltage during an opening operation and applies a reverse voltage to the electromagnetic solenoid during a closing operation. When two power sources are used, there is a method of controlling by using two power sources separately for an opening operation and a closing operation and using a three-wire system. On the other hand, there is also a method of simplifying the drive circuit by dividing the coil of the latching solenoid valve itself into an opening operation coil and a closing operation coil to form a two-coil latching solenoid valve.

  As described above, in the case of a three-wire system in which a single-coil latching solenoid valve is controlled by two power sources, one of the connection terminals to the electromagnetic solenoid is connected to the + power source, and the other is connected to the -power source and switched by a switch. The other connection terminal of the electromagnetic solenoid connects the opposite terminals of the two power sources as a common terminal. By selectively using the two power supplies, forward and reverse voltages can be applied to the electromagnetic solenoid.

  When a 1-coil latching solenoid valve is controlled by a drive circuit, it is necessary to reverse the applied voltage to the electromagnetic solenoid in the forward and reverse directions. Conventionally, an H-type bridge that uses four drive transistors to reverse the applied voltage A circuit (FIG. 4) is used. The H bridge circuit is also used for controlling a DC motor.

  In contrast, the two-coil latching solenoid valve can be opened / closed by using only one power source and two switches. Since it is not necessary to use an H-type bridge circuit that reverses the applied voltage forward and backward, the drive circuit is simple. However, since two coils are used, the size of the latch-type solenoid valve also increases. There is a drawback that the part is expensive.

  As described above, when a two-coil latching solenoid valve is controlled, the drive circuit becomes simple, but the solenoid valve is expensive. On the other hand, when controlling a one-coil latching solenoid valve, four drive transistors are used. Since an H-type bridge circuit and a microcomputer using the above are used, the drive circuit becomes expensive.

  However, considering that there is a target cost for a solenoid valve as seen in the target specifications of a household fuel cell system proposed by the Ministry of Economy, Trade and Industry, which is considered as one application, the cost of the drive circuit is of course the solenoid valve. Lowering is a current issue.

  The subject of the present invention is a latch type solenoid valve with a drive circuit that detects the ON / OFF of the power supply voltage and flows the current of the open / close operation without using a microcomputer. It is an object to provide an inexpensive latching solenoid valve that can be opened or closed at the time of turning on or off.

  Therefore, the present invention is a latch type solenoid valve for controlling the flow of fluid, and has a drive circuit for controlling the operation of the solenoid valve, and the drive circuit is controlled by two lines of a power source and GND. In the latch type solenoid valve, the energization circuit in the drive circuit controls the current to the electromagnetic solenoid by a bridge circuit formed by three transistors and one diode, and has a capacitor, and a resistor is provided downstream of the capacitor. The latch type solenoid valve is characterized in that the electromagnetic solenoid is energized without any loss of resistance by placing it, and the inrush current when the solenoid valve is opened is suppressed.

  In addition, the latch type solenoid valve according to the present invention is characterized in that the solenoid valve can be closed even when the power supply voltage is gradually lowered due to a failure or the like by being connected to the transistor via a Zener diode. Latch type solenoid valve.

  In a general H-bridge circuit, by using four drive transistors in the present invention, three drive transistors and one diode are used in the present invention, which leads to cost reduction of the latch type solenoid valve. By placing a resistor after the capacitor, the electromagnetic solenoid can be energized without a loss of resistance, and the inrush current can be suppressed, and a short circuit when the drive transistor is damaged is prevented. Since the power of the capacitor is used when the solenoid valve is closed when the power supply voltage is OFF, current does not flow to the power supply and the GND side, and the surge current when the power supply voltage is OFF can be suppressed.

  In the present invention, a Zener diode and a transistor are connected between the power supply terminal and GND. For this reason, the presence or absence of the collector current of the transistor is determined by the relationship between the power supply voltage and the Zener voltage. When the power supply voltage falls below the Zener voltage, the power supply voltage is detected to be OFF, and the base current of the transistor does not flow. Accordingly, the collector current does not flow, and the latching solenoid valve can be closed even when the power supply voltage is lowered.

  An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 are latch type solenoid valves showing an embodiment of the present invention, and also include a drive circuit connected to the solenoid solenoid. FIG. 1 shows a case where the latching electromagnetic valve 11 is in a closed state, and FIG. 2 shows a case where the latching electromagnetic valve 11 is in an opened state. The arrow indicates the direction in which fluid is taken into the solenoid valve.

  1 and 2, the latch-type solenoid valve 11 includes a main body 12, an electromagnetic solenoid 42, a fixed core 17, a movable core 15 below the movable core 15, and a movable core 15 provided between the fixed core and the movable core. A permanent magnet that latches the valve core 13 and the moving core 15 in an open state. 18 etc. The main body 12 of the latch type solenoid valve 11 has a fluid inflow hole and an outflow hole.

  In FIG. 1, the latch type electromagnetic valve 11 is in a closed state, and the moving core 15 is urged downward along the axis by a spring 16. Since the valve element 13 that contacts the tip of the lower end of the moving core 15 is urged downward in the axial direction and pressed against the main body 12, no fluid flows in a state where the fluid flow path is closed. At this time, when a current is applied to the electromagnetic solenoid 42, the moving core 15 receives an attractive force on the fixed core 17 side by the generated electromagnetic force and moves upward along the axis. As described above, the valve body 13 integrated with the moving core 15 moves upward in the axial direction of the electromagnetic valve, and the opening is opened. By adsorbing the moving core 15 and the fixed core 17, a magnetic circuit having a small magnetic resistance is formed by the ground 14, the moving core 15, the fixed core 17, the coil frame 19, and the permanent magnet 18. Even when the electromagnetic solenoid 42 is de-energized, the moving core 15 maintains the attracted state with the fixed core 17. As a result, as shown in FIG. 2, the flow path is opened, the fluid flows from the inflow hole of the main body 12 through the opening, and further passes through the flow path opened to the lower part of the valve body 15, and the outflow hole of the valve main body 1. It flows out through.

  2, when a reverse current is passed through the electromagnetic solenoid 42, an electromagnetic force is generated, which is formed by the ground 14, the moving core 15, the fixed core 17, the coil frame 19, and the permanent magnet 18. The magnetic circuit having a small magnetic resistance is demagnetized, the moving core 15 and the fixed core 17 are urged downward in the axial direction by the force of the spring 16, and the valve body 13 is pressed against the main body 12. As a result, the valve is closed as shown in FIG.

  3 and 5 show a drive circuit for the latch type solenoid valve of the present invention. Its configuration will be described later. FIG. 4 shows an H-type bridge circuit of a transistor, and shows a conventional energization circuit corresponding to the present invention. Although the conventional driving circuit corresponding to FIG. 3 according to the present invention is not shown, the transistor 35 and the transistor 34 are connected between the power supply terminal 51 and the GND, and the transistor 35 and the transistor 34 are associated with FIG. The + side of the electromagnetic solenoid 42 is connected between the two. Further, the transistor 32 and the transistor 33 are connected between the power supply terminal 51 and the GND 52, and the other electromagnetic solenoid is connected between the transistor 32 and the transistor 33.

  FIG. 5 shows only the energizing circuit portion extracted from the drive circuit according to the present invention shown in FIG. The diode 37 connected between the power supply terminal 51 and the GND 52, the capacitor 39, the capacitor 39 of the resistor 36, and the resistor 36 are connected to the emitter of the transistor 34. The power supply terminal 51 and the emitter of the transistor 34 are connected, and the + side of the electromagnetic solenoid 42 is connected between them. The diode 37 and the capacitor 39 are connected to the GND 52 via the emitter of the transistor 32 and the collector of the transistor 33. The other side of the electromagnetic solenoid 42 is connected between the collectors of the transistor 32 and the transistor 33.

  FIG. 6 shows the relationship between the power supply voltage and the current flowing through the electromagnetic solenoid, and shows a comparison between the power supply voltage and the current flowing through the electromagnetic solenoid between the latch type solenoid valve with a drive circuit of the present invention and a normal solenoid valve.

  In the conventional transistor H-type bridge circuit of FIG. 4, when a base current flows through the drive transistors 33 and 35, a current flows in the order of the power supply terminal 51, the drive transistor 35, the electromagnetic solenoid 42, the drive transistor 33, and the GND 52. A positive voltage is applied to. Further, when a base current flows through the drive transistors 32 and 34, a current flows in the order of the power supply terminal 51, the drive transistor 32, the electromagnetic solenoid 42, the drive transistor 34, and the GND 52, and a reverse voltage is applied to the electromagnetic solenoid 42.

  In the drive circuit of the present invention shown in FIG. 3, when the power supply voltage is turned on, the voltage reduced by the Zener diode 40 is applied to the IC timer 41, and a one-pulse signal determined by the time constant of the resistor 43 and the capacitor 44 is output from the IC timer 41. Output to the base of the drive transistor 33. Thereby, the collector current of the drive transistor 33 flows, and the current is supplied to the GND 52 from the power supply terminal 51 through the diode 38, the electromagnetic solenoid 42, and the drive transistor 33. The moving core 15 is attracted to the fixed core 17 side by an electromagnetic force generated by a positive current flowing through the electromagnetic solenoid 42. When the moving core 15 and the fixed core 17 are attracted, the permanent magnet 18 forms a magnetic circuit. By forming the magnetic circuit, the attracted state can be maintained, and the open state of the solenoid valve can be maintained.

When the power supply voltage is OFF or when the power supply voltage is lowered, if the power supply voltage becomes equal to or lower than the Zener voltage of the Zener diode 40, the base current of the transistor 31 does not flow and the collector current does not flow. Therefore, the power discharged from the capacitor 39 flows to the base current of the drive transistor 34, and the collector current also flows. When the drive transistor 34 is energized, a base current flows through the drive transistor 32 and a collector current also flows. When the drive transistors 32 and 34 are energized, the electric power discharged from the capacitor 39 flows to the drive transistor 32, the electromagnetic solenoid 42, and the drive transistor 34. The magnetic circuit formed by the ground 14, the moving core 15, the fixed core 17, the coil frame 19, and the permanent magnet 18 is demagnetized by the electromagnetic force generated by the reverse current flowing through the electromagnetic solenoid 42, and the moving core 15 and the fixed core are demagnetized. 17 is closed by the force of the spring 16. As a result, the solenoid valve is closed.

  As described above, in the present invention, by using three drive transistors 32 to 34 and one diode 37, the cost of the latch type solenoid valve is reduced. By placing the resistor 36 after the capacitor 39, the electromagnetic solenoid 35 can be energized without loss of resistance, and the inrush current can be suppressed, and a short circuit when the drive transistor 34 is damaged is prevented. Since the power of the capacitor 39 is used when the solenoid valve is closed when the power supply voltage is OFF, no current flows to the power supply and the GND side, and the surge current when the power supply voltage is OFF can be suppressed.

  Further, in the present invention, the Zener diode 40 and the transistor 31 are connected between the power supply terminal 51 and the GND 52. Therefore, the presence or absence of the collector current of the transistor 31 is determined by the relationship between the power supply voltage and the Zener voltage, and when the power supply voltage falls below the Zener voltage, the power supply voltage is detected to be OFF, and the base current of the transistor 31 does not flow. Accordingly, the collector current does not flow, and the latching solenoid valve can be closed even when the power supply voltage is lowered.

  FIG. 6 shows the relationship between the power supply voltage and the current flowing through the electromagnetic solenoid, and shows a comparison between the power supply voltage and the current flowing through the electromagnetic solenoid between the latch type solenoid valve with a drive circuit of the present invention and a normal solenoid valve. In the case of a normal solenoid valve, the solenoid valve is opened only when a voltage is applied and a current is passed through the coil, and when the voltage is turned off, the solenoid valve is closed. In the latch type solenoid valve of the present invention, by applying a voltage to the power source, a current flows instantaneously in the solenoid solenoid 42, and the solenoid valve is opened. Thereafter, while the voltage is applied, no current flows through the electromagnetic solenoid 42, and the valve is opened by a magnetic circuit having a small magnetic resistance formed by the ground 14, the moving core 15, the fixed core 17, the coil frame 19, and the permanent magnet 18. The state is maintained. When the power is turned off, current flows instantaneously from the capacitor to the electromagnetic solenoid 42, and the electromagnetic valve is closed. Accordingly, while suppressing power consumption used when the solenoid valve is turned on, the solenoid valve can be turned on when the power is turned on, and the solenoid valve can be turned off when the power is turned off, as in a normal solenoid valve.

Sectional drawing of the closed state of the latch type solenoid valve which shows one Example of this invention Sectional drawing of the open state of the latch type solenoid valve which shows one Example of this invention Drive circuit diagram of latch type solenoid valve of the present invention Current-carrying circuit section of the drive circuit of FIG. Conventional transistor H-type bridge circuit Relationship between power supply voltage and coil current

Explanation of symbols

11: Latch type solenoid valve 12: Body 13: Valve body 14: Ground 15: Moving core 16: Spring 17: Fixed core 18: Permanent magnet 19: Coil frame 31: Transistors 32-35: Drive transistor 36: Resistors 37-38 : Rectifier diode 39: Capacitor 40: Zener diode 41: IC timer 42: Electromagnetic solenoid 43: Resistor 44: Capacitor 51: Power supply terminal 52: GND

Claims (2)

  A latch-type solenoid valve that has an inflow hole and an outflow hole and controls the flow of fluid, and has a drive circuit that controls the operation of the solenoid valve, and the drive circuit is controlled by a power source and a GND line. In the latch type solenoid valve, the energization circuit in the drive circuit controls the current to the electromagnetic solenoid by a bridge circuit formed by three transistors and one diode, and has a capacitor, and is provided downstream of the capacitor. Latch type solenoid valve characterized in that the solenoid is energized without loss of resistance by placing a resistance on the side, and suppresses inrush current when the solenoid valve is open   2. The latching solenoid valve according to claim 1, wherein the latch is connected to the base of the transistor via a Zener diode to detect the OFF of the power supply voltage in accordance with the Zener voltage and to control the operation of the transistor.

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