JPH0135299Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic locking device that locks and holds an object moving parallel to a main body at a predetermined position, or releases the lock. The well-known electromagnetic locking device is, for example, the following device.

In FIG. 3, a push button rod 1 equipped with a push button 1a
is supported so as to be able to slide in the direction of arrow B with respect to the main body. Also, the spring 2 is resiliently repelled in the direction opposite to the arrow B.

The symbol 15 is a well-known electromagnetic plunger, and when the excitation coil 15a is energized, the actuator 15
Since b is attracted and moved to the right, the push button rod 1 is unlocked. Therefore, the push button rod 1 springs back.

The symbol C is a mechanism for switching a magnetic recording/reproducing machine using a cassette to the queue mode or the review mode. When the push button 1a is pressed, the actuator 15b moves to the right via the slope 1c. , then spring back to lock the push button rod 1 as shown. At this time, push button rod 1
The device C associated with the device C is activated and converted to queue or review mode.

, when the excitation coil 15a is energized by the output of the detection circuit of the no-signal band between the next song and the next song, the actuator 1
5a is sucked to the right, the lock of the push button rod 1 is released, and at the same time, the device C is also returned to the playback mode, which is a well-known music selection means that allows you to listen to the next song from the beginning. can be configured.
At this time, the contact pin 1b planted in the push button rod 1
is in contact with a lever 3 fixed to the main body. But this has some drawbacks.
First, the current flowing through the electromagnetic plunger 15 is about 6 volts and 1 ampere, which has the drawback of requiring a large current. Also, since the operation ends in about 1/100 seconds,
The disadvantage is that the actuator generates a large impact noise. Second, since the force for separating the actuator 15b from the push button rod 1 only needs to overcome the frictional force between them,
It should only require a small amount of force. However, it is difficult to uniformly finish the friction surface during mass production, and the friction surface gets dirty and rusts during use.
This requires relatively large force. It is common knowledge that for safe design, the frictional force and the pressing force should be approximately equal. Therefore, excitation coil 1
There is a drawback that the current applied to 5a must be increased.

The device of the present invention has succeeded in eliminating the above-mentioned drawbacks. Next, the details will be explained with reference to FIG. Components with the same symbols as in FIG. 3 are the same members, and their functions are the same.

A lever 6 is rotatably supported on the push button rod 1 by a support shaft 6a, and the lever 5 is rotatably supported by a support shaft 5a installed in the main body. The lever 6 and the lever 5 are configured to be bendable by a connecting pin 5b.

The rotating lever 4 is rotatably supported by a support shaft 4a installed in the main body, and one end of the lever 4 is in contact with a connection point between the levers 5 and 6 via a bent portion 4b. The bent portion 4c at the other end of the lever 4 closes the magnetic path open end of the yoke 16. Furthermore, lever 4 is
Made of mild steel. The yoke 16 is fixed to the main body,
An excitation coil 10 is attached.

Next, an example in which the device of the present invention is used to select music for a magnetic recording/playback machine using a cassette will be described.

Audio current is input from the terminal 21, and audio is output from the speaker 20 via the changeover switch 17. When the push button 1a is pressed to change to the state shown in the figure, the mode conversion device C is activated and the mode is changed to the cue mode. At the same time, the changeover switch 17 interlocked with the push button rod 1 is switched, the audio current is rectified by the diode 18, smoothed by the capacitor 19, and the excitation coil 10 is energized. Therefore, the levers 5 and 6 are prevented from bending, and the push button rod 1 is
Springback is also prevented, and the state shown in the figure is maintained. When the no-signal zone between the next track and the next track exceeds a set time (based on the time constant of the capacitor 19), the excitation coil 10 is de-energized and the attraction force of the yoke 16 of the lever 4 disappears. Therefore, due to the action of spring 2, push button rod 1 springs back, and mode switching device C
will return to playback mode. Therefore, the user can listen to the next song from the beginning and select a song.

The force that causes push button rod 1 to return in the direction opposite to arrow B is:
Due to spring 2 and mode switching device C,
It weighs about 1 kilogram. However, by reducing the bending angles of the levers 5 and 6, the force for pressing the bent portion 4b can be reduced to about 1/10. If the lengths of the levers on both sides of the fulcrum 4a of the lever 4 are 2:1, the suction force due to the yoke 16 will be about 1/20, or about 50 grams. Therefore yoke 1
6. The excitation coil 10 can be made smaller and the electric power can be reduced. Yoke 16, excitation coil 10
The volume is only about (20×10) millimeters, and the excitation current is about 20 milliamps.

In the above-mentioned operation, since the levers 4, 5, and 6 are rotated only by the support shafts, the frictional force is small and does not change over time, so that the operation is stable and reliable.

In the above-mentioned operation, when the push button 1a is pressed, the bending angle of the levers 5 and 6 becomes smaller, and therefore the lever 4 is rotated by the elastic force of the spring (not shown) in the direction of arrow A, and folds. The curved portion 4c closes the open end of the magnetic path of the yoke 16 and is electromagnetically attracted.

When selecting music in the review mode, the first button is pressed on the review command button and the push button rod.
It may be applied by means similar to the device shown in the figure. At this time, in order to use the excitation coil 10 in common for the song selection means in the cue and review modes, two sets of yokes 16 are provided, the excitation coil 10 is made common, and the open ends of the magnetic paths of the yokes 16 and other yokes allow It is sufficient to add a device for locking the push button rod for commanding the queue mode and review mode.

Next, referring to FIGS. 2a and 2b, a means for further saving power for locking will be explained.

In FIG. 2a, the symbol 4 indicates the end of the lever 4 in FIG. 1. The lever 4 is made of plastic, and the right end of the lever 4 has a
The magnet 7 has N and S poles magnetized and fixed as shown in the figure. The bases of yokes 13a and 13b made of pieces of mild steel are fixed to both ends of the magnet 7. Yoke (magnetic core) 14 made of a piece of mild steel
is fastened to the main body, and an excitation coil 10 is attached thereto. The magnetic path open ends of the yokes 13a and 13b are
Since it is closed by yoke 14, yoke 13
a, 13b, the magnet 7, and the lever 4 are attracted by the yoke 14, and are locked and maintained in the illustrated state.

When the excitation coil 10 is temporarily energized, the magnetic flux generated thereby is in the opposite direction to that generated by the magnet 7, so that the electromagnetic attractive force disappears. Therefore, the lever 4 rotates counterclockwise and the push button rod 1 (shown in the first figure) springs back, thereby achieving the object of the present invention. Since the excitation coil 10 only needs to be energized for a short time, power consumption is minimal. Furthermore, since the peak current value may be 10 to 20 milliamperes, the device can be made smaller and lighter. It has a feature that music selection can be completed by energizing the excitation coil 10 in a pulsed manner with a detection signal at the end of music selection. The device of the present invention can also be used in other devices requiring locks.

As explained above, compared to the electromagnetic plunger described above, it consumes extremely less power, does not generate noise, and has the effect of eliminating malfunctions caused by changes in frictional force. be. When the amount of current applied to the excitation coil 10 is made larger than the above-described conditions, the force between the yokes 13a, 13b and the yoke 14 is converted into electromagnetic repulsive force, so that the operation becomes more stable. Therefore,
It is possible to reliably prevent malfunctions (due to external vibrations, etc.).

Another embodiment for the same purpose will now be described with reference to FIG. 2b. Components with the same symbols as those in FIG. 1 are the same members, so a description thereof will be omitted.

In Fig. 2b, there are yokes 8 made of mild steel pieces on both sides of the N and S magnetic poles of the magnet 7 fixed to the main body.
a, 8b are fixed, and the magnetic path open ends of the yokes 8a, 8b are in contact with the bent portion 4c of the rotating lever 4 made of mild steel, so that the magnetic path is closed. The left end of the mild steel yoke 9 is bonded to the yoke 8b, and the right end is attached to the yoke 8b through a slight gap (approximately 0.3 mm).
It is facing a. The excitation coil 10 is connected to the yoke 8
It is attached to a. When the excitation coil 10 is temporarily energized, the magnetic flux generated by this is in the opposite direction to the magnetic flux generated by the magnet 7, so the magnetic flux disappears, and the rotating lever 4 moves counterclockwise. Since it is rotated, the same operation as in the previous embodiment is performed.

Next, the effect of the yoke 9 described above will be explained.

When the excitation coil 10 is energized, its magnetic flux passes through the magnet 7. Magnet 7 is
Since it is a ferrite magnet, its magnetic permeability is equal to that of air, and it has a large magnetic resistance.
The magnetic flux is small and therefore requires a large excitation current. With yoke 9, excitation coil 1
0 causes the magnetic flux to pass through the yoke 9 and be short-circuited, making it possible to generate a large magnetic flux. Therefore, there is an effect that the magnetic flux caused by the magnet 7 can be canceled by using a smaller excitation current. According to actual measurements, the presence of the yoke 9 can reduce the excitation current to about 1/4. Also, in this case,
Since the magnetic flux generated by the magnet 7 is also short-circuited by the yoke 9, it is necessary to use a magnet with a larger magnetomotive force. The yoke 9 uses the air gap 9a to increase magnetic resistance, but the same effect can be obtained by using a soft steel piece with a small cross-sectional area and using a saturation magnetic field. The present invention can also be implemented by replacing the electromagnetic adsorption device of the embodiment shown in FIG.

As can be understood from the above explanation, the present invention achieves the objects stated at the beginning and has significant practical effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the device of the present invention, FIG. 2 is an explanatory diagram of another embodiment, and FIG. 3 is an explanatory diagram of a conventionally known device of this type. 1...Push button rod, 1a...Push button, 2...Spring, 3...Part of the main body, 4...Rotating lever, 5,
6... Lever, C... Kyuu, review mode switching device, 4a, 6a, 5a... Support shaft, 4c, 4
b...Bending portion, 16, 13a, 13b, 8a, 8
b, 14... Yoke, 10... Excitation coil, 7...
... Magnet, 9 ... Yoke, 17 ... Selector switch, 18, 19 ... Time constant circuit, 20 ... Speaker, 15, 15a, 15b ... Electromagnetic plunger, 1c ... Slope.

Claims (1)

[Scope of utility model registration request] A manual lever is provided with a spring for springback and is supported so as to move parallel to the main body, and the manual lever is operated when the manual lever is manually moved against the elastic force of the spring. A load connected to the manual lever, a first lever whose one end is rotatably supported by a support shaft provided on a part of the manual lever, and a first lever.
A second lever has one end rotatably supported with respect to the first lever via a connecting pin provided on the other end of the lever, and the other end rotatably supported by a support shaft provided on the main body. When lever 2 and the manual lever move against the elastic force of the spring mentioned above,
The first and second levers should be in almost a straight line.
In addition, when the first and second levers are moved in the opposite direction, the first and second levers are provided with a mechanism that bends into a dogleg shape, a rotating lever rotatably supported by a support shaft, a yoke and an excitation coil, and the yoke is bent. An electromagnetic attraction device is fixed to the main body so that the open end of the magnetic path is closed by one end of the rotating lever, and the other end of the rotating lever, one end of which is attracted to the yoke, is provided with the first , a mechanism that suppresses the springback of the rotary lever when the connecting point of the second lever comes into contact with the lever, and a mechanism that controls the energization of the excitation coil to prevent the rotary lever from attracting or separating through the yoke. An electromagnetic locking device characterized by comprising a controlling electric circuit.