TWI555938B - Self-holding type solenoid valve (1) - Google Patents

Description

Self-sustaining solenoid valve (1)

The present invention relates to a solenoid valve (self-sustaining solenoid valve) which maintains a switching state after switching after energizing the electromagnetic coil and switching the switching state even if the energization is stopped.

Background of the invention

The self-sustaining solenoid valve must be energized to the solenoid when the valve is opened/closed, but has excellent characteristics even if the current does not continue to flow after the switching is completed. Therefore, it is possible to suppress power consumption, and in particular, it is widely used as a solenoid valve that operates using a battery.

The self-sustaining solenoid valve operates as follows. First, when the electromagnetic coil formed in the hollow shape is energized, the movable iron core which is given the potential energy by the valve closing spring is pulled into the electromagnetic coil, and the valve body provided at the end of the movable iron core is opened. At this time, the end portion on the opposite side of the movable iron core is in contact with the fixed iron core provided on the central axis of the electromagnetic coil, and is magnetized by the permanent magnet through the fixed iron core. Therefore, even if the energization to the electromagnetic coil is stopped, the state in which the movable iron core is pulled into the electromagnetic coil (the valve opening state) can be maintained.

On the other hand, in the state in which the valve opening state is maintained, when the current in the opposite direction to the above-described valve opening is energized to the electromagnetic coil, the electromagnetic coil This produces a magnetic force that counteracts the direction of the permanent magnet's magnetic force. Therefore, the force of the permanent magnet magnetized movable iron core can be weakened, and the end portion of the movable iron core that is in contact with the fixed iron core is easily peeled off by the potential of the valve closing spring, and the valve body provided on the other end side of the movable iron core is pressed against the valve seat and The self-sustaining solenoid valve will close the valve. Thereafter, even if the energization of the electromagnetic coil is stopped, the state in which the valve body is pressed against the valve seat (closed state) can be maintained by the potential of the valve closing spring.

When the self-sustaining solenoid valve is operated by the above principle, when the magnetic force generated by the electromagnetic coil is excessively large when the valve is closed, the electromagnetic coil can attract the movable iron core by using the residual magnetic force that cancels the magnetic force of the permanent magnet. Further, when the residual magnetic force exceeds the potential of the valve closing spring, the end portion of the movable iron core is magnetized by the fixed iron core due to the magnetic force of the electromagnetic coil, and the electromagnetic valve cannot be closed. Therefore, in order to reliably close the solenoid valve, a self-sustaining solenoid valve has been proposed which sets the voltage applied to the electromagnetic coil to a predetermined upper limit voltage or less when the valve is closed (Patent Document 1).

Advanced technical literature Patent literature

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-63060

Summary of invention

However, when the self-sustaining solenoid valve proposed above sets the voltage applied to the electromagnetic coil to be low when the valve is closed, when the battery is gradually consumed, the voltage applied to the electromagnetic coil when the valve is closed is lowered. Not easy The problem of closing the solenoid valve.

The present invention has been made in response to the above-described problems of the prior art, and it is an object of the invention to provide a self-sustaining solenoid valve which can be closed regardless of whether the battery is consumed or not.

In order to solve the above problems, the self-sustaining solenoid valve of the present invention has the following configuration. In other words, the valve body of the switching flow path is formed on one end side, and is provided in a movable iron core that is movable in the axial direction, and a valve closing spring that applies the potential energy to the movable iron core in a direction in which the valve body closes the flow path. An electromagnetic coil that pulls the movable iron core in a direction in which the valve body opens, a permanent magnet that holds the movable iron core pulled by the electromagnetic coil, and a voltage applying portion that applies a driving voltage to the electromagnetic coil. The voltage waveform of the driving voltage includes a first waveform portion that maintains a voltage for a predetermined period of time, and a second waveform portion that repeatedly maintains a voltage of the first waveform portion with a period shorter than the predetermined period. The voltage state is a lower voltage state than the high voltage state voltage.

In the self-sustaining solenoid valve of the present invention, since the voltage is maintained for a predetermined period of time in the first wave portion, a large current flows in the electromagnetic coil in accordance with the applied voltage during the voltage maintenance period. In contrast, since the second waveform portion repeats the high voltage state and the low voltage state in a shorter period of a predetermined period, the current flowing through the electromagnetic coil is repeatedly increased or decreased, and a large current flow such as the first waveform portion does not occur. In the case of electromagnetic coils shape. Further, since the magnetic force generated by the electromagnetic coil is proportional to the current flowing through the electromagnetic coil, a large magnetic force is generated in the first waveform portion, and a magnetic force smaller than the first waveform portion is generated in the second waveform portion. Therefore, when the battery is not consumed, if the valve is closed in the second waveform portion where the magnetic force is generated, even if the consumption of the battery increases and the driving voltage decreases, the first waveform portion having a large magnetic force can be self-sustaining. The solenoid valve is closed.

Further, in the self-sustaining solenoid valve of the present invention, the second waveform portion of the driving voltage can be set to be earlier than the first waveform portion.

The movable iron core of the self-sustaining solenoid valve may not be easily moved due to adhesion due to foreign matter or the like during use. However, since the second waveform portion repeats the high voltage state and the low voltage state in a short cycle, the movable iron core continuously vibrates, and as a result, the movable iron core can be returned to the movable state. Therefore, it is understood that the first wave portion can be applied after the application of the second wave portion, and the movable core can be easily operated in the second wave portion even if the movable core is not easily operated. The corrugated portion allows the self-sustaining solenoid valve to be reliably closed.

Further, in contrast to the self-sustaining solenoid valve described above, when the first waveform portion of the driving voltage is set before the second waveform portion, the following effects can be obtained. That is, when the battery consumption is increased, a voltage drop is caused during the application of the driving voltage of one portion. In the above case, when the battery consumption increases, the first waveform portion that is closed is provided before the second waveform portion, and the self-sustaining electromagnetic valve can be closed in the first waveform portion before the driving voltage is lowered. In addition, when the battery is not gradually consumed, even if the first waveform portion is provided before the second waveform portion, the driving voltage is not lowered in the first waveform portion. This makes it possible to reliably close the self-sustaining solenoid valve in the second wave portion.

Further, in the self-sustaining solenoid valve of the present invention described above, the voltage maintained by the first wave portion can be a voltage as follows. In other words, the voltage of the first waveform portion can be set such that the residual magnetic force after the magnetic force generated by the electromagnetic coil cancels the permanent magnet magnetic force becomes more effective than the valve spring that gives the potential energy to the movable iron core held by the permanent magnet. The voltage of the big magnetic force.

In this way, since the movable core is attracted by the magnetic force generated by the electromagnetic coil of the first corrugated portion during the period in which the battery is not consumed, the self-sustaining solenoid valve cannot be closed in the first corrugated portion, but the second corrugated portion is later. The magnetic force of the electromagnetic coil is reduced, so that the valve can be closed by the potential of the valve spring. Further, when the battery consumption is increased, the voltage applied to the first wave portion is lowered and the magnetic force of the electromagnetic coil is lowered. Therefore, the self-sustaining solenoid valve can be closed in the first wave portion. Therefore, regardless of the degree of battery consumption, the self-sustaining solenoid valve can be closed.

Further, in the self-sustaining solenoid valve of the present invention, the voltage when the second waveform portion is in the low voltage state can be set to the ground voltage.

In this way, the high voltage state and the low voltage state of the second waveform portion can be generated only by generating the voltage applied to the first waveform portion. Therefore, the circuit configuration of the voltage applying portion to which the driving voltage is applied to the electromagnetic coil can be simplified.

100‧‧‧Latch valve

102‧‧‧Electromagnetic coil

104‧‧‧ movable iron core

106‧‧‧Fixed iron core

108‧‧‧ permanent magnet

110‧‧‧ valve body

112‧‧‧Closed valve spring

114‧‧‧Voltage application department

200‧‧‧flow path

202‧‧‧ openings

Ia‧‧‧ current value

Imax‧‧‧ upper limit current value

Imin‧‧‧lower current value

R‧‧‧resistance

T0, T1, T2‧‧‧ time

Va‧‧‧ voltage value

Vmax‧‧‧ upper limit voltage value

Vmin‧‧‧ lower limit voltage value

Vo‧‧‧ Grounding voltage

1] (a) and (b) are explanatory views of the internal structure and operation principle of the latch valve 100 of the present embodiment.

[Fig. 2] is a view showing that the voltage for closing the latch valve 100 is limited to a predetermined one. An illustration of the reason for the voltage range.

FIG. 3 is an explanatory diagram showing a voltage waveform of a driving voltage applied to the electromagnetic coil 102.

Pass [Fig. 4] (a) and (b) are explanatory views showing the reason why the latch valve 100 can be closed regardless of the degree of battery consumption by using the voltage waveform of the present embodiment.

FIG. 5 is an explanatory diagram illustrating a voltage waveform of a driving voltage in the first modification.

FIG. 6 is an explanatory diagram illustrating a voltage waveform of a driving voltage in a second modification.

FIG. 7 is an explanatory diagram illustrating a voltage waveform of a driving voltage in a third modification.

Fig. 1 is an explanatory view showing an internal structure and an operation principle of a self-supporting solenoid valve (hereinafter, a latch valve) 100 of the present embodiment. In Fig. 1(a), a cross-sectional view of the latch valve 100 in a closed state is shown, and in Fig. 1(b), a cross-sectional view of the latch valve 100 in an open state is shown. First, reference is made to FIG. 1(a) and for the approximate internal configuration of the latch valve 100.

As shown in FIG. 1(a), the latch valve 100 has a solenoid-shaped electromagnetic coil 102 that is formed by winding a wire and is formed in a hollow shape, and is inserted into a movable core 104 in a state of being slidable in a central axis of the electromagnetic coil 102. a fixed core 106 that is fixed above the movable core 104 in the central axis of the electromagnetic coil 102, a permanent magnet 108 in the shape of a disk that is placed in contact with the upper end of the fixed core 106, and a valve body that is attached to the lower end of the movable core 104. 110, will move iron The valve 104 is a valve closing spring 112 that gives potential energy in a direction pulled out from the central axis of the electromagnetic coil 102, and a voltage applying portion 114 that applies a driving voltage to the electromagnetic coil 102. Moreover, the opening 202 of the flow path 200 is provided at a position corresponding to the valve body 110, and the valve of the potential energy is given by the valve closing spring 112 in the closed state of the latch valve 100 shown in Fig. 1(a). The body 110 plugs the opening 202, and the flow path 200 is turned off.

The latch valve 100 of the above configuration operates as follows. First, in the valve closing state shown in FIG. 1(a), a forward driving voltage is applied from the voltage applying unit 114 to the electromagnetic coil 102. The "direct voltage" as used herein means a voltage in which the direction of the magnetic force generated by the electromagnetic coil 102 and the direction of the magnetic force of the permanent magnet 108 become the same direction. As a result, the movable core 104 to which the potential energy is applied by the valve closing spring 112 is pulled up by the magnetic force of the electromagnetic coil 102. As a result, the valve body 110 is separated from the opening portion 202 of the flow path 200 and the latch valve 100 is opened. Valve status (refer to Figure 1 (b)).

Further, when the movable iron core 104 is pulled up by the electromagnetic coil 102, the upper end of the movable iron core 104 comes into contact with the lower end of the fixed iron core 106. In this way, the magnetic force of the permanent magnet 108 is efficiently applied to the movable core 104 through the fixed core 106, and the movable core 104 can be magnetized by the fixed core 106 by the magnetic force of the permanent magnet 108. In this manner, even after the movable core 104 is magnetized, even if the voltage application unit 114 stops energizing the electromagnetic coil 102, as shown in FIG. 1(b), the movable core 104 can be pulled up (opened state).

On the other hand, in a state where the movable core 104 is pulled up by the magnetic force of the permanent magnet 108, the electromagnetic coil 102 is applied against the voltage from the voltage applying portion 114. Drive the voltage to it. The term "reverse voltage" as used herein means that the direction of the magnetic force generated by the electromagnetic coil 102 and the direction of the magnetic force of the permanent magnet 108 become opposite voltages. As a result, the magnetic force of the permanent magnet 108 is canceled by the magnetic force of the electromagnetic coil 102, so that the movable core 104 cannot be magnetized against the potential of the valve closing spring 112. As a result, the upper end of the movable iron core 104 magnetized by the fixed iron core 106 is pulled away from the fixed iron core 106 by the potential of the valve closing spring 112, and the valve body 110 which becomes the lower end of the movable iron core 104 is pressed against the opening portion 202 of the flow path 200. State (closed valve state). As a result, even after the latch valve 100 is in the closed state, even if the energization to the electromagnetic coil 102 is stopped, the valve closing state can be maintained by the biasing force of the valve closing spring 112 (see FIG. 1(a)).

It can be known from the operation principle of the latch valve 100 as described above that when switching from the valve opening state to the valve closing state, the driving voltage applied to the electromagnetic coil 102 must be within a predetermined voltage range even if a driving voltage outside the range is applied. It is also impossible to close the latch valve 100. This point is explained using FIG. 2.

In FIG. 2, when the latch valve 100 in the open state gradually increases the current flowing through the electromagnetic coil 102 (hereinafter, the coil current), the magnetizing force acting on the movable iron core 104 is displayed (movable by the fixed iron core 106). The strength of the core 104 magnetization) has changed. Further, the coil current can be read by the resistance R applied to the electromagnetic coil 102 by multiplying the resistance R of the electromagnetic coil 102.

As is well known, the magnetic force generated by the electromagnetic coil 102 is proportional to the coil current. Further, as described above, when the latch valve 100 is in the valve open state, since the reverse driving voltage is applied to the electromagnetic coil 102, the electromagnetic coil The direction of the magnetic force generated by 102 becomes the direction that counteracts the magnetic force of the permanent magnet 108. Therefore, as shown by the reverse white mark in Fig. 2, when the coil current is "0", only the magnetizing force of the permanent magnet 108 can act on the movable core 104, but when the coil current is increased, as shown in Fig. 2 As shown by the line, the magnetic force of the permanent magnet 108 is weakened by the magnetic force of the electromagnetic coil 102, and the magnetizing force acting on the movable iron core 104 is gradually reduced linearly. Further, when the magnetic force of the electromagnetic coil 102 is equal to the magnetic force of the permanent magnet 108, the magnetizing force acting on the movable iron core 104 becomes "0". When the coil current is increased from the state thereof, the magnetic force of the electromagnetic coil 102 exceeds the magnetic force of the permanent magnet 108, and the magnetization force of the electromagnetic coil 102 can be applied to the movable core 104. As a result, after that, as shown by the broken line in FIG. 2, the magnetizing force acting on the movable core 104 increases linearly as the coil current increases.

Further, in the movable iron core 104, the biasing force of the valve closing spring 112 acts also in the direction in which the fixed iron core 106 is pulled away from the movable iron core 104. Since the magnitude of the potential capability is determined by the position of the movable core 104, it is conceivable that the latch valve 100 is in a valve open state (a state in which the upper end of the movable iron core 104 is in contact with the fixed iron core 106). In Fig. 2, the potential of the valve closing spring 112 is shown by a chain line. Of course, in order to close the latch valve 100 in the open state, the biasing force of the valve closing spring 112 must exceed the magnetizing force acting on the movable iron core 104. As a result, the coil current at the time of valve closing must be within the range from the lower limit current value Imin shown in Fig. 2 to the upper limit current value Imax. Moreover, when considering the resistance R of the electromagnetic coil 102, the driving voltage applied to the electromagnetic coil 102 must be in a voltage range from the lower limit voltage value Vmin (= R. Imin) to the upper limit voltage value Vmax (= R. Imax). Inside.

However, since the driving voltage is limited to the voltage range, the driving voltage is decoupled from the voltage range when the battery is consumed, and the latch valve 100 cannot be closed. Therefore, in the present embodiment, in order to close the latch valve 100 even when the battery is consumed, a driving voltage such as the following voltage waveform is applied to the electromagnetic coil 102.

Fig. 3 is an explanatory view showing a voltage waveform of a driving voltage applied to the electromagnetic coil 102 in the present embodiment. As shown in the figure, the voltage waveform of the driving voltage of the present embodiment has the first waveform portion and the second waveform portion, and the driving voltage is maintained at the voltage value Va at the time T0 across the first waveform portion. On the other hand, in the second waveform portion, the driving voltage is lowered to the low voltage state of the ground voltage Vo and the driving voltage is increased to the same voltage value as the first waveform portion in a period (T1+T2) shorter than the time T0. The high voltage state of Va. Further, in the example shown in FIG. 3, the time T1 at which the driving voltage becomes the ground voltage Vo and the time T2 at which the voltage value Va are set are the same length in the second waveform portion, but the time T1 and the time T2 may be set to be different. length. Further, the voltage value Va of the first waveform portion (high voltage state with the second waveform portion) can be set to a value higher than the upper limit voltage value Vmax (= R. Imax) by using FIG. 2 . By making the voltage waveform described above, the latch valve 100 can be closed regardless of the degree of consumption of the battery.

4 is an explanatory view showing the reason why the latch valve 100 is closed regardless of the degree of consumption of the battery by applying the driving voltage of the voltage waveform of the present embodiment. First, referring to FIG. 4(a), the case where the battery is not completely consumed will be described. Figure 4 (a) shows the application of the battery when it is completely unconsumed The coil current of the electromagnetic coil 102 flows with the driving voltage of the voltage waveform of FIG. As shown in the figure, when the voltage value Va of the first waveform portion is applied, the coil current rapidly increases, and soon becomes a current value Ia (= Va/R) and is fixed. Further, R is the resistance value of the electromagnetic coil 102. Here, even if the voltage value Va of the first waveform portion is applied, the coil current does not immediately reach the current value Ia because the electromagnetic coil 102 has a function of causing a counter electromotive force in a direction that hinders the coil current from changing. In other words, when the voltage value Va of the first waveform portion is applied, the coil current is caused to flow rapidly to the electromagnetic coil 102, but the counter electromotive force that prevents the current from increasing is generated in the electromagnetic coil 102. Therefore, even if the driving voltage of the voltage value Va is applied to the electromagnetic coil 102 in the first waveform portion, the coil current does not immediately increase to the current value Ia (=Va/R), but gradually increases toward the current value Ia. .

Thereafter, when the voltage waveform enters the second waveform portion, the driving voltage repeats the ground voltage Vo and the voltage value Va (see FIG. 3), but the operation of the coil current at this time is as follows. First, when the driving voltage is switched from the voltage value Va to the grounding voltage Vo, the coil current is drastically reduced, but the electromagnetic coil 102 has a counter electromotive force that hinders the reduction of the coil current. As a result, the coil current gradually decreases toward the current value of zero. However, before the coil current reaches the current value of 0, since the driving voltage is switched from the ground voltage Vo to the voltage value Va, the coil current is increased to the current value Ia. As a result, the counter electromotive force in the electromagnetic coil 102 in the direction in which the current increases is prevented, so that the coil current gradually increases toward the current value Ia. However, in the middle of the coil current gradually increasing, since the driving voltage is switched from the voltage value Va to the ground voltage Vo, the coil current is again reduced, but at this time Also, the back electromotive force is generated in the electromagnetic coil 102, so the coil current is gradually reduced. As described above, in the second waveform portion, the coil current is decreased while the driving voltage is the ground voltage Vo, and the driving voltage is switched to the voltage value Va and the coil current is decreased in the middle of the reduction, and the coil current is increased. The drive voltage is switched to the ground voltage Vo and the increase in the coil current is reduced. When the second waveform portion is terminated and the application of the driving voltage is stopped, the coil current is gradually reduced until the current value becomes zero.

Here, since the voltage value Va is set to a value higher than the above-described upper limit voltage value Vmax by using FIG. 2, the current value Ia at which the coil current becomes constant in the first waveform portion exceeds the upper limit current value Imax. Therefore, in the case where the first waveform portion can close the latch valve 100, only a small period of the current range from the lower limit current value Imin to the upper limit current value Imax is passed when the coil current increases toward the current value Ia. On the other hand, in the middle of the second waveform portion, the coil current in the second waveform portion is increased to increase in the middle of the current value 0, and the current is decreased in the middle of the current value Ia. The coil current is present in a current range from the lower limit current value Imin to the upper limit current value Imax. Therefore, in a state where the battery is not consumed, the driving voltage mainly closes the latch valve 100 in the second waveform portion.

In FIG. 4(b), the driving voltage applied to the electromagnetic coil 102 and the coil current flowing to the electromagnetic coil 102 when the battery consumption is increased are shown. Since the voltage generated by the battery is increased more than the predetermined voltage value, when the battery consumption increases, the voltage of the first waveform portion and the voltage of the high voltage state of the second waveform portion become higher than the original one. The voltage value (voltage value Va) is lower. Along with this, the line flowing on the electromagnetic coil 102 The loop current is also lower than the original current value. However, as described above, when the battery is not consumed, the coil current in the first waveform portion is set to be higher than the current value Ia of the upper limit current value Imax. Therefore, when the battery consumption increases, the coil current of the first waveform portion becomes a current value lower than the upper limit current value Imax and is fixed. Therefore, in a state where the consumption of the battery is increased, the coil current in the first waveform portion is not lower than the lower limit current value Imin, and the latch valve 100 can be closed in the first waveform portion of the drive voltage.

Further, as shown in FIG. 3, when the first waveform portion is placed earlier than the second waveform portion, the following effects can be obtained. That is, in a battery which is greatly increased in consumption, even if it is a voltage lower than a predetermined voltage of the battery, it is difficult to maintain it for a long time. Therefore, for example, as shown in FIG. 4(b), in the middle of the output voltage waveform (the second waveform portion in the illustrated example), the driving voltage may gradually decrease. However, since the first waveform portion is located earlier than the second waveform portion in the voltage waveform shown in FIG. 3, the latch valve 100 can be closed without being affected by the voltage drop.

As described above, if the voltage waveform of the driving voltage applied to the electromagnetic coil 102 is the voltage waveform shown in FIG. 3, the latch valve 100 is mainly closed in the second waveform portion during the period in which the battery is not consumed. When the battery starts to be consumed, the latch valve 100 can be closed mainly in the first wave portion. Therefore, the latch valve 100 can be surely closed regardless of the degree of battery consumption.

Further, in the above-described embodiment, the period in which the second waveform portion is in the low voltage state (ground voltage Vo) is generally described as the time T1. However, as shown in FIG. 5, the period from the first waveform portion to the second waveform portion and the first low voltage state can be regarded as the time T3 longer than the time T1. Such as According to the voltage waveform of the first modification, the latch valve 100 can be more reliably closed in the second waveform portion, and the period of the second waveform portion can be shortened to suppress power consumption. This is for the following reasons.

When the change of the coil current in the second waveform portion of FIG. 4(a) is observed in detail, the coil current is increased and decreased immediately after switching from the first waveform portion to the second waveform portion, and then the coil current is increased. Will gradually increase and decrease and gradually reduce, and finally become a value of stability to increase and decrease. The case where the coil current indicates the above-described operation is because the current value Ia at which the coil current is stable in the first waveform portion is higher than the current value at which the coil current in the second waveform portion is stabilized, so that the coil current is increased. It takes a lot of time to reduce it overall.

Therefore, as shown in FIG. 5, the period length (time T3) of switching to the first low voltage state of the second waveform portion is made longer than the period length (time T1) of the subsequent low voltage state. In this way, since the amount of decrease in the coil current in the first low voltage state in which the first waveform portion is switched to the second waveform portion can be increased, the second waveform portion can be quickly moved to the coil current to be stably reset. The state of increase or decrease. Therefore, since the time of the second waveform portion is substantially long, the time of the second waveform portion can be shortened only by the component, and as a result, power consumption can be suppressed.

Further, in the above-described embodiments and modifications, the case where the driving voltage is set to the ground voltage Vo in the low voltage state of the second waveform portion will be described. However, the driving voltage in the low voltage state of the second waveform portion may be a voltage lower than the voltage value Va of the first waveform portion, and may not necessarily be the ground voltage Vo.

6 is a voltage wave illustrating a driving voltage of the second modification example; An illustration of the shape. In the second modification shown in the figure, the driving voltage in the low voltage state of the second waveform portion is set to a voltage value Vb higher than the ground voltage Vo. As a result, since the fluctuation range of the driving voltage in the second waveform portion is small, the fluctuation range of the coil current flowing through the electromagnetic coil 102 is also small. As a result, since the coil current in the second waveform portion is likely to fall between the lower limit current value Imin and the upper limit current value Imax, the latch valve 100 can be surely closed in the second waveform portion of the drive voltage.

Further, in the above-described embodiments and modifications, the description will be made by providing the second waveform portion after the first waveform portion. However, the first waveform portion and the second waveform portion do not necessarily need to be in accordance with the order, as illustrated in FIG. 7, and the first waveform portion may be provided after the second waveform portion.

As shown in FIG. 3, since the second waveform portion repeats the high voltage state and the low voltage state in a short cycle, when the driving voltage is applied to the electromagnetic coil 102, the movable core 104 continuously vibrates. Therefore, even when the movable iron core 104 is hard to move (or is fixed) when the foreign matter adheres or the like, the movable iron core 104 can be returned to the state where it is easy to operate. Therefore, when the driving voltage of the voltage waveform of the first waveform portion is applied after the application of the second waveform portion, the movable core 104 can be made to operate in the second waveform portion even if the movable core 104 is not easily operated due to adhesion of foreign matter or the like. After the state of easy operation, the latch valve 100 can be closed in the first waveform portion.

Although the latch valve 100 of the present embodiment and the modified example has been described above, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the spirit and scope of the invention.

For example, in the above embodiments and modifications, the first waveform is The second waveform portion is set after the portion. However, the second waveform portion does not necessarily need to be provided after the first waveform portion, and the second waveform portion may be provided before the first waveform portion.

T0, T1, T2‧‧‧ time

Va‧‧‧ voltage value

Vo‧‧‧ Grounding voltage

Claims (4)

A self-supporting solenoid valve having a movable iron core formed on one end side of a switching flow path and provided to be movable in an axial direction, and a valve closing spring that imparts potential energy to the movable iron core in a direction in which the valve body closes the flow path An electromagnetic coil that pulls the movable iron core in a direction in which the valve body opens the flow path, a permanent magnet that holds the movable iron core that has been drawn by the electromagnetic coil, and a voltage application unit that applies a driving voltage to the electromagnetic coil. The voltage waveform of the driving voltage includes a first waveform portion that maintains a voltage for a predetermined period of time, and a second waveform portion that repeatedly maintains a voltage of the first waveform portion with a period shorter than the predetermined period. A high voltage state and a lower voltage state than the high voltage state voltage. The self-sustaining solenoid valve according to claim 1, wherein the voltage waveform of the driving voltage sets the second waveform portion to be earlier than the first waveform portion. The self-sustaining solenoid valve of claim 1 or claim 2, wherein the voltage of the first waveform portion is set such that the residual magnetic force after the magnetic force generated by the electromagnetic coil cancels the magnetic force of the permanent magnet is proportional to the permanent The potential of the valve closing spring of the movable iron core potential energy held by the magnet is a voltage of a larger magnetic force. The self-sustaining solenoid valve of claim 1 or claim 2, wherein the voltage of the low voltage state of the second waveform portion is set to a ground voltage.