JPH0737834B2 - Solenoid valve drive circuit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a drive circuit for a self-holding solenoid valve.

[Prior Art] In general, a self-holding type direct current solenoid valve for low power drive has a structure shown in FIG. When the solenoid valve is opened, a current is passed through the electromagnetic coil 1 to excite the magnetic force of the permanent magnet 2 in the direction of increasing the magnetic force. Then, the attraction force of the plunger 4 to the iron core 3 exceeds the force of the spring 8 and the plunger 4
Is adsorbed on the iron core 3, and the pilot flow path 7 is opened.
When the pilot flow path 7 is opened in this way, the pressure at the upper part of the valve body 11 drops to the pressure at the discharge port 10 side. The fluid is pushed up by the pressure of the fluid, the inflow port 9 and the exhaust port 10 communicate with each other as shown in FIG. 7, and the solenoid valve opens. At this time, even if the energization state of the electromagnetic coil 1 is stopped, the attraction state of the plunger 4 to the iron core 3 is maintained only by the magnetic force of the permanent magnet 2.

Further, when the electromagnetic valve is closed, a current is applied to the electromagnetic coil 1 in the opposite direction to the above-described case to excite the magnetic force of the permanent magnet 2 in a direction weakening the magnetic force. In this case, the attraction force of the plunger 4 to the iron core 3 is weakened and the restoring force of the spring 8 is increased, and the plunger 4 is separated from the iron core 3. Therefore, the pilot valve 5 of the plunger 4 comes into contact with the valve seat 6 and the pilot passage 7 is closed. When the pilot flow passage 7 is blocked in this manner, the fluid flows into the upper portion of the valve body 11 communicating with the low pressure pilot flow passage 7 through the check valve 11a of the valve body 11, and the valve body 11 descends. Then, it is attached to the communication port 12 and the solenoid valve is closed. Even at this time, even if the energization state of the electromagnetic coil 1 is stopped, the state in which the plunger 4 is separated from the iron core 3 is maintained only by the force of the spring 8.

In order to perform the above operation, a drive circuit that allows current to flow in both the forward and reverse directions in the electromagnetic coil 1 is required. An example of such a conventional drive circuit is shown in FIG. This drive circuit is provided with capacitors C ₁ and C ₂ for opening and closing the solenoid valve, respectively, and there is a problem that two large-capacity large capacitors are required. Moreover, in the case of this circuit, the input signals V ₁ , V ₂
Is left in the low level state,
Since Q _1, Q ₃ are each transistors Q _2, Q ₄ continues to be in an ON state, consumes unnecessary power to the opening and closing operation. Therefore,
The input signals V ₁ and V ₂ need to be pulses having a predetermined width, which causes a problem that a pulse generation circuit is required. That is, conventionally, there is a problem that the power consumption of the drive circuit cannot be reduced and the drive circuit cannot be downsized.

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and an object thereof is to provide a switching circuit for a solenoid valve that consumes less power and is small in size. is there.

[Means for Solving the Problems] In order to achieve the above object, the specific invention includes a direct current power source for supplying a unidirectional current to an electromagnetic coil of an electromagnetic valve, and a capacitor connected in series to the electromagnetic coil. A charging closed circuit that connects a series circuit of an electromagnetic coil and a capacitor and the DC power supply to allow a current in one direction to flow in the electromagnetic coil; and a charging charge of the capacitor charged by the connection with the DC power supply, which reverses the electromagnetic coil. A switching circuit is provided for switching the circuit to a discharge closed circuit for passing a current in the direction.

In the related invention, in addition to the configuration of the specific invention, a resistor for suppressing the peak value of the charging current is inserted in the charging closed circuit.

(Operation) As described above, the specific invention includes a direct current power source for supplying a current in one direction to the electromagnetic coil of the electromagnetic valve, and a capacitor connected in series to the electromagnetic coil, and a series circuit of the electromagnetic coil and the capacitor. A charge closed circuit that connects the DC power supply to flow a current in one direction to the electromagnetic coil, and a discharge closed circuit that flows a current in the reverse direction to the electromagnetic coil by the charge of the capacitor charged by the connection with the DC power supply. By providing a switching circuit for switching the circuit, a unidirectional current is made to flow to the electromagnetic coil by the DC power source, this current is made to be an instantaneous current by the capacitor, and the electromagnetic coil is charged by the charging charge charged in the capacitor. It is designed to reduce the power consumption of the drive circuit by making the current flow in the opposite direction, and it is also compact because only one capacitor is required. It was made possible.

In the related invention, by inserting a resistor for suppressing the peak value of the charging current into the charging closed circuit, it is possible to use a DC power source having a small capacity.

(Embodiment 1) FIG. 1 and FIG. 2 show an embodiment of the specified invention. The drive circuit of the present embodiment causes a direct current to flow in one direction to the electromagnetic coil 1 of the solenoid valve by the direct current power source E, and causes the direct current power source E to charge the capacitor C ₀ charged by the current flowing in the electromagnetic coil 1 to cause electromagnetic waves. A reverse current is passed through the coil 1, the capacitor C ₀ is connected in series to the electromagnetic coil 1, and the switching circuit 13 switches the circuits so that the respective currents flow through the electromagnetic coil 1. I am doing it. This switching circuit 13 is formed by connecting the series circuit of the electromagnetic coil 1 and the capacitor C ₀ and the DC power source E to connect the DC power source E to a charging closed circuit for flowing a current in one direction to the electromagnetic coil 1 and the DC power source E. The circuit is switched to a discharge closed circuit in which an electric current in the opposite direction is passed through the electromagnetic coil 1 by the charged electric charge of the charged capacitor C ₀ , so that both currents can flow in the electromagnetic coil 1. In the case of this embodiment, the switching circuit 13 is composed of the relay Ry ₁ and the transistor Q _0, and the contact r ₁ of the relay Ry ₁ is provided between the series circuit of the electromagnetic coil 1 and the capacitor C ₀ and the DC power source E. The drive circuit is switched between the charge closed circuit and the discharge closed circuit by inserting and switching the contact r ₁ .

In this drive circuit, the input signal V ₀ with high, low two states in accordance with the opening and closing of the solenoid valve to the base of the transistor Q ₀
Is input, and a bidirectional current is passed through the electromagnetic coil 1. Now, when the input signal V ₀ which high level and is input to the transistor Q _0, switches the contact r ₁ by the driving current flows to the relay Ry ₁ via the transistor Q _0. Contact r _{1 in the} initial state
Is switched to the discharge closed circuit side, contact r ₁
Is switched to the charging closed circuit side, a current flows from the DC power source E to the electromagnetic coil 1, the plunger 4 is attracted to the iron core 3 as shown in FIG. 7, and the electromagnetic valve opens by the same operation as described above. . At this time, the capacitor C ₀ is the electromagnetic coil 1
When the capacitor C ₀ is completely charged, the current from the DC power source E is cut off. That is, by connecting the capacitor C ₀ in series with the electromagnetic coil 1, a current can be instantaneously passed through the electromagnetic coil 1.

Next, when closing the solenoid valve, the low-level input signal V ₀ is input to the transistor Q ₀ . At this time, relay Ry
_Since the drive current of ₁ is cut off, the contact r ₁ is switched to the discharge closed circuit side, the charge charged in the capacitor C ₀ is discharged through the electromagnetic coil 1, and a current in the reverse direction is generated in the electromagnetic coil 1. Flowing. Therefore, as shown in FIG. 6, the plunger 4 is separated from the iron core 3 and the solenoid valve is closed.

By the way, in the above drive circuit, the transistor Q ₀ and the relay
The switching circuit 13 was constituted by Ry ₁ , but as shown in FIG. 2, the switching circuit 13 is constituted by the transistors Q _{5 to} Q ₈ and the inverter I _1.
Can also be configured. In this switching circuit 13, a transistor Q ₆ is inserted in a charging closed circuit in which the series circuit of the electromagnetic coil 1 and the capacitor C ₀ is connected to the DC power source E, and the transistor Q ₆ is connected in parallel to the series circuit of the electromagnetic coil 1 and the capacitor C _0. Q ₈
To connect the transistors Q ₆ and Q ₈ to the transistors Q ₅ and
Respectively on by Q _7, turns off control, on of the transistor Q _5, the input signal V ₀ OFF control, also on the transistor Q _7, an input signal V ₀ OFF controlled by a signal obtained by inverting by an inverter I ₁ I am going to do it.

This drive circuit turns on the power consumption Q ₆ when the input signal V ₀ is at a low level and causes the DC power supply E to flow a current in one direction to the electromagnetic coil 1, and when the input signal V ₀ is at a high level, the transistor Q ₈ Is turned on, and an electric current in the reverse direction is caused to flow through the electromagnetic coil 1 due to the charge charged in the capacitor C ₀ .

According to the structure of this embodiment, the DC power source E can supply a current in one direction to the electromagnetic coil 1, and the capacitor C ₀ can convert this current into an instantaneous current. It is possible to reduce the power consumption of the drive circuit by causing the electric current in the direction to flow in the electromagnetic coil 1 by the charged electric charge charged in C ₀ . Moreover, the condenser is 1
It can be small because it can be done individually. In addition, since the solenoid valve can be driven by using the battery, it can be safely used in a water space such as a bathroom, which has been unusable until now.
Furthermore, since the high level and low level of the input signal V ₀ correspond to closing and opening, respectively, no extra signal conversion circuit or the like is required, and therefore the drive circuit operation is directly performed by a signal from a control circuit such as a microcomputer. It also has the advantage of being controllable.

(Embodiment 2) FIGS. 3 to 5 show an embodiment of the related invention. In this embodiment, the resistor R ₀ is inserted in the closed charging circuit for charging the capacitor C ₀ , and FIG. 3 shows the resistor R ₀ provided in FIG. 1 of the above-mentioned embodiment. A discharge current does not flow through the resistor R ₀ . That is, resistance like this
By inserting R ₀ in the closed charging circuit, the peak value of the charging current can be suppressed, so that the DC power source E having a small capacity can be used. Further, it becomes possible to operate a plurality of solenoid valves at the same time. When the resistor R ₀ is provided in the circuit of FIG. 2 of the first embodiment,
It may be inserted on the emitter side of the transistor Q ₆ as shown in FIG.

The switching circuit may be composed of a self-holding switch SW having two contacts as shown in FIG. Needless to say, this self-holding switch SW can also be applied to the first embodiment.

[Advantages of the Invention] As described above, the specific invention includes a direct current power source for supplying a unidirectional current to the electromagnetic coil of the electromagnetic valve and a capacitor connected in series to the electromagnetic coil, and the electromagnetic coil and the capacitor are connected in series. A charge-closed circuit that connects a circuit and the DC power supply to allow a current in one direction to flow in the electromagnetic coil, and a discharge-closed circuit that causes a current in the opposite direction to flow in the electromagnetic coil due to the charge of the capacitor charged by the connection to the DC power supply. Since the circuit is provided with a switching circuit for switching the circuit, a current in one direction can be passed through the electromagnetic coil by the DC power supply, and this current can be made into an instantaneous current by the capacitor, and at this time, the capacitor There is an advantage that the power consumption of the drive circuit can be reduced by causing a current in the opposite direction to flow in the electromagnetic coil by the charged charge charged in the. Moreover, since only one capacitor is required, the size can be reduced. In addition, since the solenoid valve can be driven by using the battery, it can be safely used in a water space such as a bathroom, which has been unusable until now. Further, when the drive circuit is operated by the input signal, the high level and the low level of the input signal correspond to closing and opening, respectively, so that an extra signal conversion circuit or the like is not required and the microcomputer or the like can be directly controlled. There is also an advantage that the operation of the drive circuit can be controlled by a signal from the circuit.

Further, in the related invention, by inserting a resistor for suppressing the peak value of the charging current in the charging closed circuit, there is an advantage that a small capacity DC power source can be used, and it is possible to operate a plurality of solenoid valves at the same time. Becomes

[Brief description of drawings]

FIG. 1 is a circuit diagram of a drive circuit according to an embodiment of the specified invention, and FIG.
FIG. 4 is a circuit diagram of another structure of the above, FIG. 3 is a circuit diagram of a drive circuit of an embodiment of the related invention, FIGS. 4 and 5 are circuit diagrams of another structure of the same, and FIG. Sectional view of the valve in the closed state, FIG. 7 is a sectional view of the solenoid valve in the open state in the same, FIG.
The figure is a circuit diagram of a conventional drive circuit. 1 is an electromagnetic coil, 13 is a switching circuit, E is a DC power supply, C ₀ is a capacitor, and R ₀ is a resistor.

Claims (4)

[Claims] 1. A direct current power source for supplying a current in one direction to an electromagnetic coil of an electromagnetic valve, a capacitor connected in series to the electromagnetic coil, and a series circuit of the electromagnetic coil and the capacitor connected to the direct current power source. A switching circuit that switches the circuit between a charging closed circuit for flowing a current in one direction to the electromagnetic coil and a discharging closed circuit for flowing a current in the opposite direction to the electromagnetic coil by the charge stored in the capacitor charged by the connection with the DC power supply. A drive circuit for a solenoid valve, comprising: 2. A direct current power source for supplying a unidirectional current to an electromagnetic coil of an electromagnetic valve, a capacitor connected in series to the electromagnetic coil, and a series circuit of the electromagnetic coil and the capacitor connected to the direct current power source. A switching circuit that switches the circuit between a charging closed circuit for flowing a current in one direction to the electromagnetic coil and a discharging closed circuit for flowing a current in the opposite direction to the electromagnetic coil by the charge stored in the capacitor charged by the connection with the DC power supply. A drive circuit for a solenoid valve, comprising: a charging closed circuit, and a resistor for suppressing a peak value of a charging current inserted therein. 3. The solenoid valve drive circuit according to claim 1, wherein the switching circuit is manually switched. 4. A drive circuit for a solenoid valve according to claim 1, wherein the switching circuit is switched by an input signal.