JPH04102776A - Solenoid valve driving circuit - Google Patents

Abstract

PURPOSE:To eliminate a capacitor having a large capacity, and obtain a compact solenoid valve driving circuit by comprising a driving current switching circuit for switching the driving current from a driving current charging and discharging circuit to any solenoid valve with the control signal from a control circuit. CONSTITUTION:In the case of flowing the ordinary directional current to a solenoid coil 4a, a CPU 2 controls transistors Tr2, Tr3 OFF and a transistor Tr1 ON to close only a relay Ry1. Thereafter, the L level pulse signal is output to an input terminal 3x of a driving current charging and discharging circuit 3, and the discharged current is flowed as the ordinary directional current of the solenoid coil 4a through a contact point of the relay Ry1 to open the solenoid valve. In the case of flowing the reverse directional current to the solenoid coil 4a, the CPU 2 controls the transistors Tr2, Tr3 OFF and the transistor Tr1 ON to close only the relay Ry1. Thereafter, the L level pulse signal is output to an input terminal 3y, and the discharged current is flowed as the reverse directional current of the solenoid coil 4a through the contact point of the relay Ry1 to close the solenoid valve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solenoid valve drive circuit using a self-holding solenoid valve.

[Prior Art] In general, self-holding type solenoid valves aimed at low-power single-motion operation require driving current to flow in the forward and reverse directions to the solenoid valve solenoid in order to perform the opening and opening operations. be. Regarding the driving method and 1-2, it is possible to use a switching element such as a transistor to switch the drive current. Figure 2 shows two capacitors (
-:1. The method of using C2 to instantaneously create a drive current by charging and discharging is effective because the drive current is not influenced by internal resistance. When used in a piping system using multiple solenoid valves, as shown in Fig. If you don't stutter, you have to get h2,
There was a problem in that the circuit was large in both height and area.

The present invention has been provided in view of the above points, and by distributing the drive current to a plurality of solenoid valves using a drive current switching circuit, the large capacity capacitor that occupies the largest area can be reduced. The purpose of this invention is to provide a compact electromagnetic valve drive circuit.

[Means for Solving the Problems] The present invention provides a set of a plurality of self-holding electromagnetic valves, a control circuit that generates opening/closing signals for the electromagnetic valves, and a set of internal charging and discharging according to the opening/closing signals from the control circuit. A drive current charging/discharging circuit charges and discharges the electric charge of the capacitor and supplies a driving current to the solenoid valve using the current accompanying the charging or discharging of the capacitor, and a drive current from the drive current charging/discharging circuit according to a control signal from the control circuit. and a drive current switching circuit that switches the current to any electromagnetic valve.

[Function] Therefore, the drive current switching circuit is switched and controlled by the control signal from the control circuit to supply the drive current from the drive current charging/discharging circuit to any solenoid valve, even in the case of multiple solenoid valves.
By switching and controlling the drive current with the drive current switching circuit, the capacitor can be used as only one set of the drive current charging/discharging circuit.
We are trying to reduce the number of capacitors.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the self-holding type solenoid valve A will be explained with reference to FIGS. 3 and 4. FIG. 3 shows the open state. When a current is applied to the electromagnetic coil 4 and excited in a direction to strengthen the magnetic force of the permanent magnet 10, the force of the spring 11 is exceeded, the plunger 12 is attracted to the iron core 9, and the pilot valve 13 is opened. , since the pilot flow path 14 is opened, the main valve 16 is pushed up,
It is in an open state as shown in FIG. At this time, even if the electromagnetic coil 4 is de-energized, the attracted state is maintained only by the magnetic force of the permanent magnet 10.

When a current is applied to the electromagnetic coil 4 in the open state shown in FIG. 4 to excite it in a direction that weakens the magnetic force of the permanent magnet 10, the force of the spring 11 is exceeded, the plunger 12 is pulled away from the iron core 9, and the pilot valve 13 is closed. Since the pilot flow path 14 is blocked, the main valve 16 is depressed and the third [! I
It is in the closed state as shown in . At this time, even if the electromagnetic coil 4 is no longer energized, the separated state is maintained only by the force of the spring 11.

FIG. 1 shows an overall block circuit diagram, which includes a battery 1 that supplies power to the entire circuit, a control circuit constituted by a CPU 2, and a 21st! A drive current charging/discharging circuit 3 consisting of the circuit shown in I and a switching relay Ry
3, and a drive current switching circuit 6 consisting of transistors Trl to Trs for driving the same. Further, the contacts of the relay RF+ of the drive current switching circuit 6 are connected to the electromagnetic coil (solenoid) 4a of the electromagnetic valve.

As shown in FIG. 2, the drive current charging/discharging circuit 3 includes transistors T r 4 to T ry, capacitors C+, Cz,
It is composed of a resistor R1, etc. Now, when an L level pulse signal is input to the input terminal 3x, which is normally in an H level state, the input to the transistor Tr4 becomes an L level, and the transistor Trn is turned on, turning on the transistor Tr. .

When the transistor Tr is turned on, the capacitor C2 is discharged, and a forward current flows from the output end 3a to the output end 3b via the electromagnetic coil 4.
The solenoid valve performs an opening operation.

When an L level pulse signal is input to the input terminal 3y, which is normally at H level, the input to transistor Tr5 becomes L level, transistor Tr5 is turned on, and transistor Try is turned on.

When the transistor Try is turned on, the capacitor C5 is discharged, and a reverse current flows from the output end 3b to the output end 3a via the electromagnetic coil 4.
The solenoid valve performs a closing action.

Note 2: In this circuit, the capacitors C, , C, which were being charged
By discharging the electric charge, forward and reverse drive currents flow through the electromagnetic coil 4, but the circuit configuration may be changed so that the drive current is supplied to the electromagnetic valve by the charging current of the capacitor. .

Next, the operation shown in FIG. 1 will be explained. Now, if you try to apply a forward current to the electromagnetic coil (solenoid) 4a, C
PU2 is a transistor Tr2. Tr3 is controlled to be off, transistor Trl is controlled to be on, and relay R is
Only F+ is closed. Thereafter, an L level pulse signal is output from the CPU 2 to the input terminal 3X of the drive current charge/discharge circuit 3, and the discharge voltage from the drive current charge/discharge circuit 3 is output.
1! The (driving current) flows as a forward current in the electromagnetic coil 4a through the contacts of the relay RF +, and the electromagnetic valve becomes open.

Next, when trying to flow a reverse current through the electromagnetic coil 4a,
CPU2 includes transistor Tr2. Tr3 is off,
The transistors T7 are controlled to be on, and the relay RF
After that, the CPU 2 outputs an L level pulse signal to the input terminal 3y of the drive current charge/discharge circuit 3, and the discharge current from the drive current charge/discharge circuit 3 connects the contact of the relay RF+. A reverse current flows through the electromagnetic coil 4a, and the electromagnetic valve is closed.

In addition, when passing current through the other electromagnetic coils 4b or 4c, only the corresponding transistors may be turned on, and a latching type relay may be used as the relay.In this case, the capacitor is not driven. Since only one set is used for the current charging/discharging circuit 3, the leakage current due to the capacitor is reduced, so that the life of the battery 1 can be extended.

[Effects of the Invention] As described above, the present invention includes a plurality of self-holding solenoid valves,
A control circuit that generates an opening/closing signal for the solenoid valve, and a set of internal charging/discharging capacitors that are charged and discharged according to the opening/closing signals from the control circuit, and the current accompanying the charging or discharging of the capacitor generates a drive current to the solenoid valve. The device is equipped with a drive current charging/discharging circuit that supplies The drive current switching circuit is switched and controlled by the control signal to supply the drive current from the drive current charge/discharge circuit to any solenoid valve. Therefore, even in the case of multiple solenoid valves, the drive current can be changed to By switching and controlling the capacitor with a switching circuit, the number of capacitors can be reduced by using only one set of drive current charging/discharging circuits. Since the capacitors can be used as one set for opening and closing operations, the circuit can be made very compact. Furthermore, since the number of capacitors is reduced, leakage current due to the capacitors is reduced.

In addition, since the leakage current due to the capacitor is reduced, by configuring the drive current charging/discharging circuit with a latching relay,
It is possible to extend the life of the battery as a power source, and even if the scale of the system increases and the number of solenoid valves increases, the number of relays only increases and the number of capacitors does not increase. It is effective enough to become a system.

[Brief explanation of the drawing]

1st [! l is an overall block circuit diagram of an embodiment of the present invention;
Figure 2 is a circuit diagram of the drive current charging and discharging circuit same as above, Figure 3 is a cross-sectional view of the same solenoid valve in the closed state, Figure 4 (!I is a cross-sectional view of the same solenoid valve in the open state, and Figure 5 is a block circuit diagram of a conventional example. 3 is a drive current light discharge circuit, 6 is a drive current switching circuit, and A is a drive current light discharge circuit.
is a solenoid valve. Agent Patent Attorney Ishi 1) Chief 7 Figure 4 procedural amendment (voluntary) November 24, 1990

Claims (2)

[Claims] (1) A plurality of self-holding solenoid valves, a control circuit that generates open/close signals for the solenoid valves, and a set of internal charging and discharging capacitors that charge and discharge according to the open/close signals from the control circuit. a drive current charging/discharging circuit that supplies a drive current to the solenoid valve using the current associated with charging or discharging the capacitor;
A solenoid valve drive circuit comprising a drive current switching circuit that switches the drive current from the drive current charging/discharging circuit to an arbitrary solenoid valve in response to a control signal from the control circuit. (2) The electromagnetic valve drive circuit according to claim 1, wherein a latch type relay is used in the drive current charging/discharging circuit.