JPH0228742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slow-acting device that uses magnetic coupling to seal liquid inside a cylinder to completely prevent liquid leakage.

Currently, shock absorbers, dampers, and the like are widely used as slow-acting devices that use liquid. These slow-acting devices used special oil seals or flexible membranes to prevent leakage of the liquid sealed inside the cylinder. However, when using an oil seal, it is impossible to completely prevent liquid leakage, and the movement of the piston increases the pressure inside the cylinder, so it has the disadvantage of requiring an accumulator, etc. .

On the other hand, those using flexible coatings had problems with durability. Particularly in the case of a device with a long stroke, a large bending stress is applied to the coating, so that it is not suitable for a slow-acting device with a very long stroke.

A first object of the present invention is to make it possible to completely seal a liquid inside a cylinder by utilizing magnetic coupling in consideration of the above-mentioned points. Further, since the internal pressure does not change due to the movement of the piston and no rubber coating is used, it is possible to easily manufacture a piston with a long stroke.

A second object of the present invention is to provide a delay device which can maintain the latched state of the piston at the end of its stroke and can electrically control unlatching.

The latch-type slow-acting device using magnetic coupling according to the present invention has a double-tube structure in which a liquid is sealed between a ring-shaped cross section formed by an outer cylinder and an inner cylinder, and It consists of a cylinder having a hollow part extending along the axis, and a pair of magnetic bodies arranged facing each other through the inner cylinder wall, at least one of which is a permanent magnet, and of the pair, the magnetic body is loaded into the ring-shaped gap. a first magnetic body disposed so as to be slidable in the axial direction of the cylinder while receiving resistance from the liquid; a second magnetic body coupled to the cylinder; an operating rod having one end fixed to the second magnetic body and the other end of which is disposed so as to be able to protrude and retract outward from the cylinder; and the second magnetic body. a yoke that is disposed at the stroke end of the second magnetic body to form a magnetic path and attract and hold the second magnetic body when it is seated; It is characterized by having an operating rod holding mechanism consisting of an excitation coil for releasing the magnetic attraction force between the actuating rods.

The present invention will be explained below based on the drawings.

FIG. 1 is a diagram showing an embodiment of a latch-type delay device according to the present invention, which is provided with a holding mechanism that can electrically control the operating rod. Cylinder 1 is shown in Figure 1a.
As shown in , it has a hollow cylindrical shape having an outer cylinder 1a and an inner cylinder 1b having a predetermined distance 1c between the outer cylinder 1a and the hollow part 1d formed by the inner wall of the inner cylinder 1b. ing.

A viscous liquid 2 such as silicone oil is sealed in the space 1c, and a first cylindrical magnet 3 magnetized in the NS direction in the axial direction is moved in the axial direction of the cylinder while receiving resistance from the viscous liquid. It is stored and loaded so that it can slide back and forth. The other end of the cap 1c containing the magnet 3 and the liquid 2 is sealed with a stopper 5 made of rubber or the like, and a cap 6 having a hole from which an operating rod 8 (described later) projects is attached to the upper part.

Further, 4 and 4' shown in FIGS. 1a and 1b are return springs for urging the operating rod 8 upward. The arrangement position is between the first magnet 3 and the spring 4 shown in FIG. 1a.
between the magnet 3 and the bottom of the second magnet 3.
The operating rod 8 may be biased back upward indirectly through the magnet 7, or a spring 4' formed at the upper end of the operating rod 8, like a spring 4' shown in FIG. It may also be arranged between the flange portion 8' and the cap 6 to directly bias the operating rod 8.

On the other hand, the hollow part 1d of the cylinder 1 has an inner cylinder 1b.
A second magnet 7, which is magnetically coupled to the first magnet 3 through the peripheral wall of the cylinder, is disposed so as to be able to slide back and forth in the axial direction of the cylinder. As shown in FIG. 1c, the first magnet 3 and the second magnet 7 are magnetized to have NS2 poles and face each other. Note that instead of the first and second magnets described above, one may be made of a ferromagnetic material such as iron.

Further, one end of an operating rod 8 is inserted and fixed into the second magnet 7, and the other end of the operating rod 8 passes through a hole in the cap 6 and projects to the outside of the cylinder. The operating rod 8 and the hole in the cap 6 are connected to the first
As shown in Figure d, it has a partially cut-out anti-rotation shape.

A base 9 is mounted below the cylinder 1, and a yoke 10 and an excitation coil 1 are fitted in the center of the base 9, which are inserted and arranged below the hollow part 1d of the cylinder 1.
A retaining mechanism for the operating rod consisting of 1 is attached.

The yoke 10 of this holding mechanism is made of a ferromagnetic material that attracts and latches when the lower part of the second magnet 7 is seated and comes into contact with it, as shown in FIG. 1e. The excitation coil 11 is wound around the center of the yoke 10 and is energized so that it forms a magnetic field opposite to the magnetic field created by the second magnet 7 and repulses and separates.

Next, the operation of the latch type slow-acting device of this embodiment will be explained.

When the operating rod 8 is pressed, the second magnet 7 descends, and as a result, the first magnet 3, which is magnetically coupled to the second magnet 7, absorbs the elastic force of the spring 4 and the viscous liquid. It slides down while experiencing the viscous resistance of 2. At this time, if the sliding clearance of the magnet 3, that is, the distance between the outer cylinder 1a or the inner cylinder 1b and the first magnet 3 is large, the liquid resistance experienced by the magnet 3 is small, so that a relatively fast and slow operation can be obtained. On the other hand,
If this clearance is made small, the liquid resistance increases, resulting in a slower and slower operation.

Next, when the second magnet 7 reaches the stroke end and comes into contact with the yoke 10, a part of the magnetic flux passes through the yoke 10. Due to the magnetic attraction force created between the second magnet 7 and the yoke 10,
Even if the external force pressing the actuating rod 8 is removed, the retracted state of the actuating rod 8 is latched and maintained, so the actuating rod 8 does not return and remains stationary.

Next, when the excitation coil 11 is energized, a magnetic field opposite to the magnetic field created by the second magnet is generated, and the magnetic attractive force between the two is released. Therefore, the second
The magnet 7 and yoke 10 repel each other,
The second magnet 7 is spaced apart from the yoke 10.

Here, the first magnet 3 is urged in the return direction by the elastic force of the spring 4, but the viscous liquid 2
Due to the action of viscous resistance, it slowly rises, and the second magnet 7 and operating rod 8 also move slowly upwards.

As described above, since the present invention utilizes magnetic coupling force, it can be operated with the liquid inside the cylinder completely sealed, and a slow-acting device without liquid leakage can be provided. In particular, unlike conventional sealing methods using special coatings, long strokes can be easily produced.

In addition, by using a part of the magnetic flux of the magnet, which mainly acts as a magnetic coupling, it is possible to temporarily hold the operating rod back by suction, and this can be controlled at any timing using an electric signal. It is possible to obtain a latch-type delay device that can be released.

By utilizing this in the eject mechanism of a cassette tape recorder, video tape recorder, etc., the range of applications is wide, such as being able to electrically control graceful eject operations.

[Brief explanation of drawings]

FIG. 1 is an embodiment of the slow-acting device according to the present invention, in which a is a vertical cross-sectional view showing a spring disposed inside the outer periphery, and b is a longitudinal cross-sectional view showing a spring disposed around the upper part of the operating rod. Longitudinal cross-sectional view, c is an end view taken along the line A-A showing the arrangement relationship between the first and second magnetic bodies, and d is the first
Figure a is a plan view showing the arrangement relationship between the operating rod and the cap, and figure e is an exploded perspective view showing the second magnet, yoke, and excitation coil. 1...Cylinder, 2...Viscous liquid, 3...First
magnet, 4, 4'...spring, 5...
stopper, 6...cap, 7...second magnet, 8...operating rod, 9...base, 10...yoke, 11...excitation coil.

Claims (1)

[Claims] 1. Formed in a double cylinder structure in which a liquid is sealed between a ring-shaped cross section formed by an outer cylinder and an inner cylinder,
and a cylinder having a hollow part along the axis, and a pair of magnetic bodies disposed facing each other through the inner cylinder wall, at least one of which is a permanent magnet, and of the pair, the ring-shaped space is a first magnetic material loaded in the cylinder and disposed so as to be slidable in the axial direction of the cylinder while receiving resistance from the liquid; a second magnetic body magnetically coupled to the magnetic body; one end fixed to the second magnetic body;
The other end includes an operating rod disposed so as to be able to protrude and retract from the outside of the cylinder, and an operating rod disposed at the stroke end of the second magnetic body to form a magnetic path when the second magnetic body is seated. An operating rod holding mechanism comprising: a yoke that attracts and holds the yoke; and an excitation coil that is wound around the yoke and releases the magnetic attraction force between the second magnetic body and the yoke. A latch-type slow-acting device that utilizes magnetic coupling.