JPS58221182A - Timer of eddy current plate type - Google Patents

Abstract

PURPOSE:To adjust easily the speed of a rotating body with a simple mechanism, by disposing permanent magnets oppositely to both sides of a freely rotatable eddy current disc concentrically with said disc, and adjusting the turning of one of said magnets. CONSTITUTION:The counter magnetic poles of permanent magnets 4, 10 which are disposed to face to each other are so disposed that the dissimilar poles oppose to each other. If a gear 9 is rotated, an eddy current disc 6 rotates, and eddy current is generated in the disc 6, by which the braking force is applied on the disc 6 and the speed of the disc 6 is adjusted to rotate at a specified number of revolutions. When a magnetic induction plate 11 is rotated, the magnet 10 rotates as well. If the speed is so adjusted that the same poles of the magnets 4 and 10 face to each other, the disc 6 rotates at a high speed without generating the brake.

Description

[Detailed description of the invention] The present invention relates to an eddy current plate timer.

The eddy current plate type timer has permanent magnets arranged on both sides of an eddy current plate made of copper or aluminum, and either the eddy current plate or the permanent magnet is a rotating body, and the rotation of this rotating body generates eddy currents in the eddy current plate. This occurs so that a braking force is applied to the rotation of the rotating body.

By the way, such a vortex plate type timer requires a speed regulating mechanism for regulating the desired constant rotation speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vortex plate timer that can easily adjust the speed of a rotating body using a simple mechanism.

An embodiment of the present invention will be described below with reference to FIG. A support shaft 3 is fixed to the inside of one of the two base plates 1.2 arranged in parallel.

A magnet mounting shaft portion 3a is formed on the support shaft 3 on the ground plate 1 side,
A vortex disk mounting shaft portion 3b is formed to protrude from the magnet mounting shaft portion 3a toward the base plate 2 side. The inner diameter portion of the magnetic induction plate 5 to which the permanent magnet 4 is fixed is fixed to the magnet mounting shaft portion 3al. A non-magnetic pipe shaft 7 to which an eddy current disk 6 is fixed is rotatably inserted into the eddy current disk mounting shaft portion 3b.
The pipe shaft 7 is vertically positioned by a collar 81 fixed to the tip of the vortex disk mounting shaft portion 3b. A gear portion is provided on the outer periphery of the vortex disk 6I, and a gear 9 rotated by a drive source (not shown) meshes with this gear portion. A magnetic induction plate 11 to which a permanent magnet 10 disposed opposite to the permanent magnet 4 is fixed is rotatably inserted into the other base plate 2, and a speed nut or the like is attached to a portion protruding outward from the base plate 2. A fixing spring 12 is engaged to fix the base plate 21. Also, the ground plate 2 of the magnetic induction plate 11
Outer end of (This is the groove 1 for engaging a screwdriver etc.)
1a is formed. In addition, the two permanent magnets 4.1
For example, in Figure 2, ζ
As shown, the opposing surfaces are multipole magnetized.

Now, the opposing magnetic poles of the permanent magnets 4.10 arranged opposite to each other are arranged so that the opposite poles N and S face each other as shown in FIG.
A drive source (not shown) is started to rotate the gear 9. This causes the vortex disk 6 to rotate and therefore the vortex disk 6
Due to the magnetic flux of the permanent magnets 4.10, eddy currents are generated and a braking force is applied to the eddy current disk 6, so that the eddy current disk 6 is controlled and rotates at a constant rotational speed.

Next, the $11a# driver of the magnetic guide plate 11 is engaged to rotate the magnetic guide plate 11. This causes the permanent magnet 10 to also rotate. Then, the opposing poles of the two permanent magnets 4.10 are the same, that is, N and N, and S and 8. Even when the eddy current disk 6 rotates, almost no eddy current is generated in the eddy current disk 6, and the eddy current disk 6 rotates at high speed without being braked.

In this way, if the opposing magnetic poles are different, the maximum braking l
By making the opposing magnetic poles the same polarity, the braking can be adjusted to the minimum level, so that the desired rotational speed can be adjusted freely within the braking range by arranging the opposing permanent magnets 4.10. Permanent magnets 4.10 on both sides of the rounded vortex disk 6
Since it has a very simple structure in which one permanent magnet is configured to be rotatably adjustable, it can be made inexpensive and thin.

Moreover, since it is a complete magnetic circuit, there is no magnetic flux leakage, and there is no effect even if a magnetic body is brought close to the outside.

In the above embodiment, one permanent magnet 10 is rotatably adjustable, but both permanent magnets 4 and 10 may be rotatably adjustable. It is also possible to form the protrusion to be long and to fix a pointer or the like to this protrusion.

As is clear from the above description, according to the present invention, a rotatable vortex disk is provided, and four permanent magnets are arranged concentrically with the vortex disk, facing each other on both sides of the vortex disk. Since at least one of the permanent magnets is rotatably adjusted concentrically with the eddy current disk, the speed can be easily adjusted to a desired rotational speed.Also, the structure is extremely simplified, It can be made inexpensive and thin.Since it is a completely magnetic circuit, there is no leakage flux, and it has the advantage that there is no effect even if a magnetic body is brought close to it from the outside.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the speed regulating mechanism of an eddy current timer according to the present invention, and FIG. 2 is a plan view showing an example of the permanent magnet shown in FIG. l, 2...Main plate, 3...Support shaft, 4...
Permanent magnet, 5... Magnetic induction plate, 6... Eddy current disk, 10... Permanent magnet, 11... Magnetic induction plate, 12... Fixed spring. 5- Figure 1 Figure 2

Claims (1)

[Claims] A vortex disk is rotatably provided, and permanent magnets concentric with the vortex disk are arranged opposite to each other on both sides of the vortex disk,
A eddy current plate type timer in which at least one of the permanent magnets is rotatably adjustable concentrically with the eddy current disk.