JP2003014154A - Solenoid valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the time for opening and closing a solenoid valve device even in the case of using a driving solenoid outputting a large driving force with a small current value. SOLUTION: A permanent magnet 7 for attracting a movable core 3 when initially electrifying a coil till the predetermined time passes is provided in a driving solenoid provided at a side opposite to a fixed core of the movable core 3, or the permanent magnet is provided in the driving solenoid at side opposite to the fixed core of the movable core 3. When initially electrifying the coil, attraction of the permanent magnet 7 is larger than the fixed core 1, and after the predetermined time is passed, the attraction force of the fixed core 1 is larger than the attraction force of the permanent magnet 7 and the hydraulic reaction force of a ball valve 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve device, and for example, it is adopted in a hydraulic actuator in a gas circuit breaker,
Particularly, the present invention relates to a solenoid valve device suitable for driving a ball valve type pilot valve having a large hydraulic load by a drive solenoid.

[0002]

2. Description of the Related Art A conventional solenoid valve device will be described below with reference to FIGS.

FIG. 3 shows the structure of a conventional solenoid valve device.

A conventional solenoid valve device is composed of a drive solenoid and a pilot valve portion. The drive solenoid is
Fixed core 1 having a hole in the center, and this fixed core 1
The coil 2 is wound around the fixed core 1, and the movable core 3 is fixed to the push rod 4 which is arranged in the magnetic circuit including the fixed core 1 and which is inserted through the hole of the fixed core 1. Further, the pilot valve portion includes an operating rod 5 that is operated by the push rod 4 (moving to the left in FIG. 3), and a ball valve that opens and closes the flow path of the hydraulic oil of the hydraulic actuator by operating the operating rod 5. 6
Consists of. Then, a suction force is generated between the fixed core 1 and the movable core 3 by the current flowing through the coil 2, and the push rod 4 of the movable core 3 is moved leftward to operate the operation rod 5. By the way, the drive solenoid that drives the ball valve 6 having a large hydraulic load has a large number of turns of the coil 2 because it is necessary to generate a large drive force with a small current value.
As the number of turns increases, the inductance of the coil 2 increases and the current rises slowly.

Usually, when a small current flows through the coil 2 in the initial stage, the magnetic circuit with the fixed core 1 is magnetized, so that the movable core 3 is attracted to the fixed core 1 and thereby the push rod 4 fixed to the movable core 3. Run to the left until the robot reaches the control rod 5. When the push rod 4 reaches the operating rod 5, the operating rod 5
When is pressed, the ball valve 6 is pressed. However, at the time when the push rod 4 starts pushing the ball valve 6 via the operation rod 5, the current rises slowly and the current is not yet sufficiently large as described above, and the attraction force of the fixed core 1 is small, so that the ball The valve 6 cannot be pushed all at once and is pushed back by the hydraulic reaction force of the ball valve 6, so that the movable core 3 cannot move and stagnates. Then, when the current flowing through the coil 2 becomes large and the suction force exceeds the hydraulic reaction force, the ball valve 6
Press to open the hydraulic fluid flow path.

[0006]

The problem of the conventional solenoid valve device shown in FIG. 3 will be described with reference to FIG.

FIG. 4 is a diagram showing the attraction force characteristic of the drive solenoid of the solenoid valve device and the stroke characteristic of the movable core 3.

When the free running of the movable core 3 is completed and the push rod 4 starts pushing the ball valve 6 via the operating rod 5 (point A)
Then, since the attraction force of the drive solenoid is much smaller than the hydraulic reaction force of the ball valve 6, the movable core 3 cannot continue its operation and stays there (in FIG. 4, the movable core 3 moves from point A to point B). Although it is expressed that the ball valve 6 does not move until the point, the side that opens the ball valve 6 and the side that pushes back by the hydraulic reaction force of the ball valve 6 closes the ball valve 6,
That is, after oscillating on the side above the horizontal dashed line between the points A and B in the stroke characteristic of FIG. 4 and stagnation at the position of the horizontal dashed line). After that, when the current flowing through the coil 2 increases and the suction force exceeds the hydraulic reaction force (point B), the ball valve 6 is first pushed to open the flow path of the hydraulic oil.

As described above, since the movable core 3 oscillates in the left-right direction of FIG. 3 due to the hydraulic reaction force of the ball valve 6, the attraction force characteristic of the drive solenoid is not as stable as that shown in FIG. Further, the hydraulic reaction force of the ball valve 6 also varies depending on the state (for example, temperature) of the hydraulic oil and is not constant. Therefore, the stagnation time of the movable core 3, that is, the time between the points A and B is not constant. As a result, the time from the application of the opening / closing control signal to the solenoid valve device until the ball valve 6 is completely opened varies, making the opening / closing operation time of the solenoid valve device unstable.

As a method for preventing this, the idling distance is made sufficiently large so as to obtain a sufficient inertial force during the idling period, or conversely, the idling distance is completely eliminated so as not to operate while the current is rising. However, none of them have sufficient operating characteristics.

An object of the present invention is to solve the above-mentioned problems and to provide a solenoid valve device having a stable open / close operation time even if a drive solenoid that produces a large driving force with a small current value is used. is there.

[0012]

According to the present invention, in order to achieve the above object, the movable solenoid is attracted to the drive solenoid on the side opposite to the fixed core of the movable core when the coil is initially energized, and is moved after a predetermined time has elapsed. Provide a permanent magnet that can release the attraction of the core, or provide a permanent magnet on the drive solenoid on the side of the movable core opposite to the fixed core, and when the coil is initially energized, the attraction of this permanent magnet is larger than the fixed core.
The attraction force of the fixed core is greater than the attraction force of the permanent magnet and the hydraulic reaction force of the ball valve after a predetermined time has elapsed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a diagram showing the construction of an embodiment of an electromagnetic valve device of the present invention.

The solenoid valve device of the present embodiment has a structure in which a magnetic circuit having a permanent magnet 7 as a main element is attached to the drive solenoid of the conventional solenoid valve device shown in FIG. The magnetic circuit having the permanent magnet 7 as a main element includes a movable core 3, a permanent magnet 7 provided in a drive solenoid on the side of the movable core 3 opposite to the fixed core 1, and a yoke provided around the movable core 3. 9 and a plate 8 that covers them. Since the permanent magnet 7 is vulnerable to mechanical vibration, in order to prevent the movable core 3 from colliding with the permanent magnet 7, the stopper 10 is fixed to the magnetic circuit device on the fixed core 1 side by the screw 11, and the air gap 12 is fixed. The movable core 3 and the permanent magnet 7 are separated by a predetermined distance or more. The movable core 3 is always attracted to the permanent magnet 7 side by the permanent magnet 7 through the air gap 12.
In addition, an air gap 1 is provided between the movable core 3 and the yoke 9.
By providing 3, the change in the attractive force of the permanent magnet 7 can be reduced even if the distance of the air gap 12 between the movable core 3 and the permanent magnet 7 changes due to the assembly tolerance.

FIG. 2 shows the attraction force characteristic of the drive solenoid and the stroke characteristic of the movable core 3 in this embodiment.

First, when a current flows through the coil 2 (during initial energization), the magnetic circuit with the fixed core 1 is magnetized and the movable core 3 begins to receive an attractive force toward the fixed core 1 side. Since the attraction force of 7 is larger, the movable core 3 remains latched by the permanent magnet 7 and does not operate. However, during that time, the current flowing through the coil 2 increases, and the attraction force on the fixed core 1 side gradually increases. After a lapse of a predetermined time, when the current becomes large and the attraction force on the fixed core 1 side becomes greater than the attraction force on the permanent magnet 7 side, the movable core 3 starts to move to the left for the first time (point C). Then, the push rod 4 of the movable core 3 runs idle until it reaches the operation rod 5, but the suction force on the fixed core 1 side at the start point (point C) of the operation of the movable core 3 is the conventional example (see FIG. 4). It is already sufficiently larger than the left end), and when the movable core 3 operates and separates from the permanent magnet 7, the attraction force on the permanent magnet 7 side sharply decreases according to the separation distance. The suction force to move in the direction is much larger than that of the conventional example. Therefore, since the push rod 4 of the movable core 3 reaches the operation rod 5 immediately, the idle time is shorter than that of the conventional example. At the time when the movable core 3 pushes the ball valve 6 via the operating rod 5 (point D), the current flowing through the coil 2 is sufficiently large and the attraction force on the fixed core 1 side is sufficiently large, so the movable core 3 Can open the ball valve 6 at a stroke without stagnation (that is, the suction force of the fixed core 1 is larger than the hydraulic reaction force of the ball valve 6). Therefore, the movable core 3 is not pushed back by the hydraulic reaction force of the ball valve 6. In this embodiment, since the movable core 3 pushes the ball valve 6 without stagnation from the start of the operation, the inertial force is sufficiently large, and the force for opening the ball valve 6 is much larger than the conventional example. Since the operation stagnant state of the movable core 3 which has made the opening / closing operation time of the conventional solenoid valve device unstable is eliminated by providing the permanent magnet 7, the opening / closing operation time of the electromagnetic valve device can be stabilized. . By appropriately selecting the attractive force of the permanent magnet 7, the opening / closing operation time of the solenoid valve device can be set to a desired value.

[0018]

According to the present invention described above, it is possible to stabilize the opening / closing operation time of the solenoid valve device even if a drive solenoid that produces a large drive with a small current value is used.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a solenoid valve device of the present invention.

FIG. 2 is a diagram showing a suction force characteristic of a drive solenoid and a stroke characteristic of a movable core of the present invention.

FIG. 3 is a diagram showing a configuration of a conventional solenoid valve device.

FIG. 4 is a diagram showing a suction force characteristic of a drive solenoid and a stroke characteristic of a movable core of a conventional example.

[Explanation of symbols]

1 fixed core 2 coils 3 movable core 4 push rod 5 control rod 6 ball valve 7 Permanent magnet 8 plates 9 York 10 stopper 11 screws 12 air gap

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Tsuchiya             1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock             Hitachi, Ltd. Electric Systems Division (72) Inventor Masayuki Uchiyama             1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock             Hitachi, Ltd. Electric Systems Division (72) Inventor Atsushi Watanabe             1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock             Hitachi, Ltd. Electric Systems Division F-term (reference) 3H106 DA07 DA13 DA26 DB02 DB12                       DB23 DB32 DC04 DD03 EE05                       GA13 GC02 KK15

Claims (3)

[Claims] 1. A fixed core having a hole in the center, a coil wound around the fixed core, and a coil disposed around one end of the fixed core so as to face the fixed core, and a current is passed through the coil to attract the fixed core. A movable solenoid, a drive solenoid fixed to the movable core, the drive solenoid comprising a push rod that moves in the hole of the fixed core according to the operation of the movable core, and the push rod located on the other side of the fixed core. And a pilot valve section that is arranged opposite to the operation rod and that is operated by being pushed by the push rod, and a pilot valve section that is composed of a ball valve that opens and closes a flow path of hydraulic oil to the hydraulic actuator by the operation of the operation rod. In the solenoid valve device, the drive solenoid on the side opposite to the fixed core of the movable core,
An electromagnetic valve device, comprising: a permanent magnet that attracts the movable core when the coil is initially energized and releases the attraction of the movable core after a predetermined time has elapsed. 2. A fixed core having a hole in the center, a coil wound around the fixed core, and a coil disposed around one end of the fixed core so as to face the fixed core by passing an electric current through the coil. A movable solenoid, a drive solenoid fixed to the movable core, the drive solenoid comprising a push rod that moves in the hole of the fixed core according to the operation of the movable core, and the push rod located on the other side of the fixed core. And a pilot valve section that is arranged opposite to the operation rod and that is operated by being pushed by the push rod, and a pilot valve section that is composed of a ball valve that opens and closes a flow path of hydraulic oil to the hydraulic actuator by the operation of the operation rod. In the electromagnetic valve device, a permanent magnet is provided in the drive solenoid on the side opposite to the fixed core of the movable core, and the attraction force of the permanent magnet is larger than that of the fixed core during initial energization of the coil. An electromagnetic valve device characterized in that the attraction force of the fixed core is greater than the attraction force of the permanent magnet and the hydraulic reaction force of the ball valve after a lapse of a fixed time. 3. The solenoid valve device according to claim 1, wherein the drive solenoid is provided with a stopper for preventing the movable core from colliding with a permanent magnet.