JPS5952430B2 - readable magnetic indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement in a magnetic indicator having a self-holding function.

[Background of the invention]

As shown in FIG. 1, the magnetic display device includes a magnetic pole 1 having residual magnetic properties, a display body 2 with a permanent magnet that can be freely reversed around a rotating shaft 3, and a set and reset coil that is an excitation coil 4 that magnetizes the magnetic pole 1. It consists of

When a current is passed between SR of the excitation coil 4 as shown in Fig. 1,
Magnetic lines of force 5 are generated as shown in the figure, magnetic poles 1 and 10 are magnetized as S poles, and magnetic poles 10 as N poles, and the display body 2 having a permanent magnet is attracted to the magnetization polarity of each magnetic pole, and the first display surface Stabilize with A facing up.

Even if the current is cut off, the magnetic pole 1 remains magnetized, so it maintains its state. Next, as shown in Figure 2, when a current is passed between SC of the excitation coil 4, the magnetic pole 1 is magnetized to the north pole and the magnetic pole 10 is magnetized to the south pole, the display body 2 is reversed, and the second display surface B is the front surface. Be on your side.

As shown in FIG. 3, the conventional technology for electrically reading out the display state of the display device is to provide a readout coil 6 on the magnetic pole 1, and the readout coil 6 detects the induced voltage and determines the magnitude of the voltage. It is connected to the detection circuit 7.

The detection circuit 7 causes a current to flow through the excitation coil 4 and detects the magnetic pole 1 according to the magnitude of the voltage induced in the readout coil 6 at that time.
There is a method of determining the magnetization direction, that is, the display state. This magnetic indicator is magnetized to 4 in the reset state, and when current is applied to the excitation coil 4, the magnetization of magnetic pole 1 moves from 4 to @, and when the current is cut off, it moves from @ to Θ, and the Θ state ( set state). Further, when a current is applied to the excitation coil 4, the magnetization moves from Θ to 〇, and when the current is turned off, it becomes the 4th state and maintains the 4th state.

The readout coil 6 has ΔB/ΔH voltage is induced.

The magnetization direction of the magnetic pole 1 is detected by passing a current between SC of the excitation coil 4. When a current is passed through the excitation coil while it is magnetized to 4, the magnetization moves from 4 to ○, and the readout occurs. Coil 6 has ΔB(4→@)/ΔH(4→
@) ・・・・・・・・・(1) Gate voltage is induced.

For example, this corresponds to the case where the second display surface B is on the upper side as shown in FIG. In addition, when a current is passed between SR of the excitation coil 4 in a state where it is magnetized to ○, the magnetization moves from (c) to (d), and the readout coil 6 has ΔB((c)→(d))/ Δ
H ((c)→(d))...The voltage of (2) is induced.

For example, this corresponds to the case where the first display surface A is on the upper side as shown in FIG. In this way, whether the first display surface A is on the top or
This means reading out whether the second display surface B is on the lower side. However, since there is a gap G between the magnetic pole 1 and the display body 2, the magnetic flux of the lines of magnetic force 5 leaks through the gap.

Therefore, 1ΔB/ΔH is extremely small, and the induced voltage is small. ΔB/Δ when changing from 24→@ and when changing from (c) →
The difference in H is small, and the difference in the induced voltage of the readout coil 6 is small.

Therefore, there was a drawback that it was difficult to read which of the first display surface A and the second display surface B was the upper surface and which was the lower surface.

[Purpose of the invention]

An object of the present invention is to provide a readable magnetic display with increased induced voltage.

[Summary of the invention]

The magnetic display of the present invention achieves the above object by providing the reading coil on a closed magnetic iron core provided at the magnetic pole via a magnetic shielding plate.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 5 and 6. Parts that are the same as those in FIGS. 1 to 3 are given the same numbers and their explanations will be omitted.

A U-shaped magnetic pole 1 having an opening 1A at one end is provided with a closed magnetic circuit iron core 8 with a magnetic shielding plate 9 in between, and a reading coil 6 is wound around the iron core 8.

Since the iron core 8 is made of a ferromagnetic material, it has a hysteresis characteristic close to a rectangular shape. The excitation coil 4 of the set coil and reset coil is wound around the magnetic pole 1 and the iron core 8 at the same time.
If a current is passed between CS and SR of the exciting coil 4 in this magnetic indicator, the characteristics shown in FIG. 6 can be obtained.

In FIG. 6, reference numeral 10 indicates the magnetization characteristics of the magnetic pole 1, and reference numeral 11 indicates the magnetization characteristics of the iron core 8. Magnetization characteristic 11 is (c) (d) = ΔB1/
ΔH. If we compare the size with 4(d)=ΔB2/ΔH, Δ
The difference between B1/ΔH and ΔB2/ΔH is clear. Therefore, the voltage difference induced in the readout coil 6 is large, and the detection circuit 7 can easily determine whether the display surface is the first display surface A (ΔB1/ΔH) or the second display surface B (ΔB2/ΔH). It became like that. [Effects of the Invention] As described above, according to the magnetic display of the present invention, the front and back sides of the display can be easily read.

[Brief explanation of the drawing]

Figures 1 to 3 are perspective views showing conventional magnetic indicators;
4 is a characteristic diagram of the magnetic display shown in FIG. 3, FIG. 5 is a perspective view of the magnetic display shown as an embodiment of the present invention, and FIG. 6 is a characteristic diagram of the magnetic display shown in FIG. 1...Magnetic pole, 2...Display body, 2...
...Display surface, 3...Rotation axis, 4...
Excitation coil, 6... Readout coil, 7...
・Detector, 8... Closed magnetic iron core, 9... Magnetic shielding plate.

Claims (1)

[Claims] 1 Arrange a magnetic pole with an opening and a display body with a magnet in the opening, provide an excitation coil and a readout coil in the magnetic pole, and apply a current in the forward or reverse direction to the excitation coil to magnetize the magnetic pole in the forward or reverse direction. In a device that inverts the display body to the front or back side and detects whether the display body is front or back based on the magnitude of the induced voltage generated in the reading coil, a magnetic shield plate made of ferromagnetic material is inserted between the magnetic poles and the magnetic shield plate. A magnetic indicator characterized by having a closed iron core and a reading coil provided on the closed iron core.