JPS6047965B2 - magnetic orientation sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic azimuth sensor for a device that uses earth's magnetism to display azimuth, and particularly to a magnetic azimuth sensor in which an output winding is wound in an innovative manner.

A common method for determining the direction of travel in a moving object such as a car is to use a magnetic needle, but since the interior of a car is shielded from magnetism by the iron body, it is difficult to know the exact direction. It was difficult, so the driver stopped the car, got out of the car, and turned on the magnetic A1L! LEI,,) 1 layer υ゛J
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In recent years, as a way to solve this problem, a magnetic direction sensor that detects the magnetic field lines of the earth's magnetic field is installed on the outside of the car body in a place that is not subject to magnetic shielding, and an electrical signal related to the detected direction is transmitted to the inside of the car, for example. Various azimuth display devices have been proposed that guide the user to an indicator provided on a dashboard in front of the driver's seat and inform the current direction of travel based on the pointer position of the indicator.

Fig. 1 shows a conventional example of a magnetic orientation sensor for this type of device, where 1 is a magnetic orientation sensor, 2 is a core (magnetic core) formed in an annular shape from a magnetic material having high magnetic permeability, and 3 is a core. The AC excitation winding is wound toroidally around the entire circumference of the core 2 to excite the core 2 to a sufficient extent to saturate the core 2.

4 and 5 are output windings for extracting only the second harmonic signal of the AC excitation signal generated in the core 2 by the magnetic lines of force generated by the excitation winding 3 and the lines of magnetic force due to the surrounding magnetic field (earth magnetism). , are wound so as to surround mutually opposing portions of the core 2 around which the excitation winding 3 is wound along the orthogonal X and Y axes.

The output signals of the output windings 4 and 5 are amplified to a predetermined level by an amplifier, and converted into an analog quantity by an integrating circuit or the like to operate an indicator. By the way, in this magnetic orientation sensor 1, after winding the excitation winding 3 around the core 2, first winding one output winding, for example, the output winding 4 positioned so as to wrap around the core 2 along the X-axis, and then winding the excitation winding 3 around the core 2. the other output θ along the Y axis so as to wrap the output winding 4 wound around the core 2 in a crossed state.
This is for winding the winding 5. Therefore, the average diameters of the output winding 4 wound on the inside and the output winding 5 wound on the outside when viewed from the core 2 are different, and the former is shorter than the latter. this is,
This type of magnetic orientation sensor lacks the theoretical condition that accurate direction can only be obtained when the two output windings 4 and 5 are wound with equal average diameters, and its use has been extremely difficult until now. Damages reliability. As a result, the output windings 4 and 5
In order to correct the difference in the average diameter between the wires, methods such as adjusting the winding using a winding jig or installing a different type of error correction device between the magnetic direction sensor 1 and the indicator have been used. In addition, the installation of the correction device requires a large-scale construction of the entire direction display device, which inevitably increases costs.

Figure 2 shows another conventional example of a magnetic direction sensor.
The core 2 and the AC excitation winding 3 of the magnetic orientation sensor 1 are the same as those of the conventional example shown in FIG. 1, but the way the output windings 4 and 5 are wound is different. That is, the two output windings are each divided into two parts,
Output windings 41 and 42 wound along the X axis
The excitation winding 3 is wound symmetrically with respect to the center of the excitation winding 3, and is connected differentially with respect to the alternating current signal applied to the excitation winding 3.

The same applies to the output windings 51 and 52, but they are wound at positions symmetrical to the center of the core 2 along the Y-axis orthogonal to the X-axis, and the AC signal applied to the excitation winding 3 is The wires are wired to be differential with respect to each other.

This magnetic azimuth sensor 1 has two output windings with different flat diameters, as in the conventional magnetic azimuth sensor 1 shown in FIG. “It never happens.

However, each output winding is divided into two parts, and a total of four winding operations are required.

For this reason, even if automatic winding is performed using a dedicated machine, the work will inevitably become more difficult when compared to the conventional example shown in FIG. ;
The present invention has been made in view of these conventional drawbacks, and it is an object of the present invention to provide a magnetic azimuth sensor in which an output winding is wound around a core using a new method. Below, Figure 3~
An embodiment of the magnetic four-magnetic direction sensor of the present invention is shown based on FIG.

Figure 3 shows a magnetic orientation sensor with an excitation winding wound around it, where 1 is the magnetic orientation sensor, 2 is a core (magnetic core) formed in an annular shape from a magnetic material exhibiting high magnetic permeability, and 3 is the core 2. The AC excitation winding is wound toroidally around the entire circumference of the core 2 to excite it to a sufficient extent to saturate the core 2.

4 to 6 are diagrams showing how to wind the output winding. It is assumed that the excitation winding 3 is wound around the core 2 and is not shown in the figures. Over the entire circumference of the core 2 around which the excitation winding 3 is wound, two coils are wound in a toroidal manner so that the winding start and winding end are aligned at the same point.
Wind the output windings 4 and 5 of the book together (Figure 4).

Connecting portions 4a, 4b, 4c, and 5a of the output windings 4 and 5 of the core 2 are connected to a total of three locations having an angular difference of 90 degrees from the center of the core 2, starting from the starting point of the output windings 4 and 5 of the core 2. , 5b, and 5c are provided (Fig. 5). Connection portions 4a and 4c of output winding 4 located along the X-axis are cut, and connection portion 5b of output winding 5 located along the Y-axis is cut.

These output windings 4 and 5 are connected differentially to the AC signal applied to the excitation winding 3, as shown in the equivalent circuit shown in FIG. Connect the wires so that they are symmetrical with angular differences (Figure 6).

From the output windings 4 and 5 terminals of the magnetic orientation sensor 1, when the core is excited by the excitation winding 3, an output signal corresponding to the direction, or direction, of the lines of magnetic force of the surrounding magnetic field is obtained.

However, this magnetic orientation sensor 1 is attached to a location outside the vehicle body that is not subject to magnetic shielding, and electrical signals related to the obtained direction are remotely guided into the interior of the vehicle.
By amplifying it to a predetermined level, converting it to an analog value using an integrating circuit, etc., and sending it to the indicator installed on the dashboard, it is possible to know the current direction of travel based on the position of the indicator on the indicator. Needless to say. The magnetic orientation sensor 1 according to the invention has two output windings 4, 5.
It is possible to match the winding conditions without the average diameter of the wires differing.

Therefore, there is no need to provide a special winding adjustment jig or a special compensation device.

Furthermore, since the excitation winding 3 and the output windings 4 and 5 are both wound in a toroidal manner over the entire circumference of the core 2, the same winding device can be used and the process can be simplified.

The magnetic orientation sensor 1 manufactured as shown in Fig. 6 is entirely molded with a resin molding material, etc., except for the terminal portions of the excitation winding 3 and output windings 4 and 5, and is press-fitted into a plastic case and sealed. The windings will not sag or shift.

As described above, according to the present invention, it is possible to extremely easily manufacture an advanced magnetic azimuth sensor with little output error.

This magnetic orientation sensor is particularly effective in detecting weak lines of magnetic force, and since it has no mechanical parts, it is not affected by external vibrations.

Since it can be miniaturized, it is convenient to use as a detection device for a device that displays the traveling direction of a moving object such as a car.

[Brief explanation of drawings]

FIG. 1 shows a conventional example of a magnetic orientation sensor. FIG. 2 shows another conventional example of a magnetic direction sensor. FIG. 3 is a diagram showing the relationship between the core and the excitation winding of the embodiment of the magnetic orientation sensor of the present invention. FIG. 4 to FIG. 6 are diagrams showing how to wind the output winding of the same sensor. FIG. 7 is an equivalent circuit diagram of the output winding of the same sensor. 1... Magnetic direction sensor, 2... Core, 3... Excitation winding, 4, 5...
・Output winding.

Claims (1)

[Claims] 1 has an annular magnetic core placed in an external magnetic field, an excitation winding wound around this magnetic core, and first and second output windings wound together and toroidally around the entire circumference of the magnetic core, The first output winding is cut at two points symmetrical with respect to the center of the magnetic core, and the second output winding is separated from the cut points of the first output winding with respect to the center of the magnetic core. The first output winding is cut at two places having an angular difference of 90 degrees, and the first output winding is connected differentially to the AC signal applied to the excitation winding. The second output winding, which is divided into two parts, is connected differentially with respect to the AC signal applied to the excitation winding and has an angular difference of 90 degrees from the first output winding. Applying an AC excitation voltage to the excitation winding, and detecting the angle formed by the magnetic core and the external magnetic field using electric signals obtained from a circuit consisting of the first output winding and a circuit consisting of the second output winding. A magnetic orientation sensor featuring: