JPH0358671B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetic sensor.

[Conventional technology]

Generally, this type of magnetic sensor includes a primary excitation coil that can be wound in a fixed direction on a ring-shaped core;
It has a secondary coil arranged so that the magnetic flux linkage is substantially zero with respect to the excitation magnetic flux generated by the primary coil. Now, if a magnetic field is applied in a certain diametrical direction of the iron core, both ends of the secondary coil will be affected by the magnitude of the input axis direction component of the secondary coil of the magnetic flux within the iron core caused by the magnetic field. the second corresponding to the orientation
A harmonic voltage (hereinafter referred to as secondary voltage) appears. At this time, if a plurality of secondary coils are arranged with different input axes, the direction of the applied magnetic field, that is, the magnetic orientation can be determined from the secondary voltage appearing in each secondary coil.

[Problem that the invention seeks to solve]

However, in this type of magnetic sensor, if there is an imbalance in the winding distribution of the secondary coil, the direction of the input axis thereof will deviate from the desired direction, resulting in a magnetic orientation error.

Conventionally, in order to obtain high magnetic orientation accuracy in such magnetic sensors, it is necessary to accurately determine the section where the secondary coil is to be wound on the annular core, and to wind the secondary coil within this section. Methods have been used such as wrapping as uniformly as possible and finally selecting the desired precision through inspection or testing, but with such conventional methods, the desired precision cannot be obtained. However, if the cause of the problem was the winding of the coil, there was a serious drawback in that after removing the coil, the coil had to be carefully wound again.

[Means for solving problems]

The present invention provides a magnetic sensor that eliminates the above-mentioned drawbacks of the conventional magnetic sensor. The primary coil is protruded in the central axis direction at an end surface of the primary coil winding frame concentric with the annular core in the same number as the secondary winding group or an integral multiple thereof, and is spaced at equal intervals. By winding each part of the primary coil winding frame between the partitioning protrusions to be arranged with an equal number of turns, and sandwiching the protrusion from the front and back in the direction of the central axis of the primary coil winding frame, the above 1. A pair of secondary coil winding frames are provided for positioning the secondary coil, and two of the pair of secondary coil winding frames are provided.
arranging the secondary coils at equal intervals on the next coil winding frame, each having an equal number of turns, and winding a correction coil approximately in the center between the secondary coils with each having the same number of turns; The primary coil wound on the annular iron core is housed inside the pair of secondary coil winding frames, and the correction coil is connected to the secondary coil as necessary, so that the secondary coil can be The direction of the input shaft is corrected.

[Effect]

In a magnetic sensor having a primary coil wound on an annular core and a secondary coil consisting of two or more winding groups, the secondary coils are arranged at equal intervals around the annular core, each having an equal number of turns. Furthermore, by winding a correction coil with an equal number of turns approximately in the center between each of the secondary coils, and connecting the correction coil to the secondary coil as necessary, the input shaft of the secondary coil can be adjusted. The direction of the magnetic field is corrected to obtain high magnetic azimuth accuracy.

Furthermore, by tightening the pair of secondary coil winding frames with the secondary coil and correction coil,
The primary coil wound on the annular core can be stably housed inside the pair of secondary coil winding frames, and as a result, the positioning between the primary coil and the secondary coil can be accurately and It can be done reliably.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is an exploded perspective view of an embodiment of the magnetic center according to the present invention, and FIG. 2 is a sectional view taken along a plane perpendicular to the central axis (0-0) in the assembled state. In the figure, 1 indicates the annular primary coil assembly of the magnetic sensor as a whole, and 21 and 21' indicate the cylindrical secondary coil assembly that houses and holds the primary coil assembly 1 therebetween. Each coil winding frame is shown. In addition, both secondary coil winding frames 21, 21' are 1
Regarding the next coil assembly 1, it is symmetrical.

The annular core 110 of the primary coil assembly 1 is housed in an annular primary coil winding frame 121 having a U-shaped cross section. This primary coil winding frame 121 has a plurality of pieces having the same size and the same shape, parallel to the central axis (0-0) and protruding to the right in FIG. 1, at equal intervals on its circumference. For example, six protrusions 141
...has 146. On the other hand, the primary coil winding frame 12
The winding frame lid 122 of No. 1 has an annular shape similar to the former, and has central axis (0-0) at equal intervals on its circumference.
Six protrusions 141', each of the same size and shape, are parallel to and protrude to the left in FIG. 1.
...has 146'.

The winding frame lid 122 has its projections 141'...14
6' and the protrusion 141 of the primary coil winding frame 121...
146 on the same circumference, 1
The next coil is attached to the winding frame 121. The primary coils 131...136 are arranged on the primary coil winding frame 121 and the winding frame cover 122, which are integrated as described above, and on the portions between the pair of protrusions thereof, with the same number of turns and in the same direction. The primary coil assembly 1 is thus formed.

Both secondary coil winding frames 21 and 21' have concentric annular grooves 210 at their bottoms, and when storing the primary coil assembly 1, the primary coil assembly 1
Projections 141...146 and 141'...14
The circular arc portion 6' is the annular groove 21 of both winding frames 21, 21'.
The side wall 211 of the annular groove 210 is in contact with at least one of the side walls 211 and 212 of the annular groove 210, respectively.
and 212 diameters are selected. Incidentally, at this time, there is no particular need to provide side walls that do not face each other.
In addition, the depth h ₁ of each annular groove 210 and each protrusion 141 . . . 146 and 141' . The lengths l ₁ and l ₂ (l ₁ = l ₂ ) that can protrude in the direction of the central axis (0-0) of Its thickness is selected to be larger. Furthermore, the depth from the open end surface 220 of each of the secondary coil winding frames 21, 21' to the bottom of the annular groove 210 provided therein.
h ₂ is the distance between both end faces in the direction of the axis (0-0) of the paired projections 141...146 and 141'...146' provided on the primary coil winding frame 121 and the winding frame cover 122. It is selected to be slightly smaller than one-half of l. In order to assemble the primary coil assembly 1 into the secondary coil winding frames 21 and 21', the primary coil winding frame 121
and a protrusion 141 provided on the winding frame lid 122...
146 and 141'...The centers of 146' are the projections 141 provided on the secondary coil winding frames 21 and 21', respectively.
...146 and 141' ... The same number of protrusions 241 for partitioning secondary coils as 146' ... 246 and 2
41'...246'.
On the other hand, the secondary coils 261...266 are connected to the secondary coil winding frame 2 in which the primary coil assembly 1 is housed.
Winding storage section 231...2 between the protrusions 1 and 21'
36 and 231'...236' are each wound with the same number of turns (see Figure 3), and two of the opposing sets are wound with the same number of turns.
Next coil 261, 264; 262, 265 and 2
63 and 266 are connected with opposite polarity to the excitation magnetic flux, and three sets of secondary coils are connected in a star or delta configuration, respectively. Incidentally, the circumferential lengths of the winding frames 21, 21' of the winding storage portions 231...236 and 231'...236' of the secondary coils, that is, the lengths of the arcs, are all equal and equally spaced. It is arranged so that it spans.

In FIG. 1, the symbols 251...256 and 25
1'...256' are respective projections 241...246 and 24 of the annular secondary coil winding frames 21 and 21'.
1'...246' is a slot provided on the upper surface of the approximately central portion. After holding the primary coil assembly 1 between both secondary coil winding frames 21 and 21' and winding the secondary coils 261...266 thereon as described above,
Corresponding slots 251, 251' of both secondary coil winding frames 21, 21'; 252, 252'...25
6, 256', correction coils 271, 272, respectively.
...Wrap 276 (see Figure 2).

3A is a side view of the magnetic sensor constructed as described above, and FIG. 3B is a sectional view taken along the line BB in FIG. 3A.

The above is a three-phase winding structure, in which the secondary coils facing each other across the central axis (0-0) are connected with opposite polarity to the excitation magnetic flux and used as a set, and the primary coil is Although the magnetic sensor according to the present invention has been described in which the secondary coil is wound on top of the magnetic sensor, the present invention is not limited to this example.
Of course, it can be applied to magnetic sensors of four or more phases, and the secondary coil is not limited to the case where the above-mentioned two opposing coils are used as a set. It may be wrapped over the top.

Furthermore, the same effect can be obtained even when the present invention is applied to a type in which the primary coil is disposed outside the secondary coil.

Note that many changes and changes may be made without departing from the gist of the invention.
It will be obvious that modifications may be readily made by those skilled in the art.

〔Effect of the invention〕

According to the present invention, three sets of secondary coils 261 and 26 are connected with opposite polarity to the excitation magnetic flux as described above.
4; 262, 265 and 263, 266 are secondary coils A, B, and C, respectively. Now, suppose that the input axis of the secondary coil A deviates clockwise from the desired direction, and as a result, the azimuth accuracy of the magnetic sensor cannot meet the required value.
In the conventional method, it was necessary to rewind the secondary coil A. However, in the magnetic sensor of the present invention, the correction coils 276 and 273 on one side of the secondary coils A are connected to the secondary coils 261 and 264, respectively. The input axis direction is biased counterclockwise from the direction before the correction coil is connected, and the input axis of the secondary coil A is corrected. If the input shaft of secondary coil A is deviated counterclockwise from the desired direction,
A correction coil 27 is connected to the secondary coils 261 and 264.
By connecting 6 and 273, the input shaft direction of the secondary coil A is biased clockwise from the direction before the correction coil is connected, and the input shaft direction of the secondary coil A can be corrected as described above. . Similarly, the direction of the input axis of the other secondary coils B and C can be corrected by appropriately selecting and connecting adjacent correction coils. Incidentally, although not shown, intermediate taps are provided in the secondary coils 261...266, and the values thereof are determined by the correction coil 27.
The value is selected so that the effective number of turns of the secondary coil does not change before and after the connection of 1 to 276.
Also, by relating the number of turns of the correction coils 271...276 to the number of turns of the secondary coils 261...266, the amount of deflection of the magnetic direction based on the deflection of the input shaft of the secondary coil caused by this is expressed as: 2 of allowable magnetic orientation error
If it is selected twice, the allowable magnetic orientation error is equivalently 3.
As a result, the yield of the magnetic sensor according to the present invention is significantly improved compared to conventional magnetic sensors of this type.

Furthermore, the intermediate tap provided on the secondary coil can be used to adjust the sensitivity of each secondary coil (correcting imbalance in sensitivity between secondary coils A, B, and C, etc.), and can also be used for correction. By appropriately connecting the coils, it is also possible to adjust the sensitivity of the secondary coil with almost no deflection of the input shaft.

Furthermore, the intermediate tap provided on the secondary coil and the correction coil can also be used for balance adjustment (zero adjustment) of each of the secondary coils A, B, and C.

Further, according to the present invention, it is possible to accurately and reliably position the primary coil and the secondary coil, and the positioning can be performed extremely quickly.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of one embodiment of the magnetic sensor according to the present invention, Fig. 2 is a sectional view taken along a plane perpendicular to the central axis when the magnetic sensor is assembled, and Fig. 3A is the same when assembled. The side view of Figure 3B is its B-
It is a sectional view along the B line. In the figure, 1 is the primary coil assembly, 21, 2
1' is a secondary coil winding frame, 110 is an annular core, 12
1 is the primary coil winding frame, 122 is the winding frame lid, 131~
136 is the primary coil, 141 to 146, 141'
~146', 241~246, 241'~246'
210 is a protrusion, 210 is an annular groove, 211 and 212 are side walls, 231 to 236 and 231' to 236' are winding storage parts, 261 to 266 are secondary coils, 251
~256 and 251'~256' are slots, 27
1 to 276 indicate correction coils, respectively.

Claims (1)

[Scope of Claims] 1. In a magnetic sensor having a primary coil wound on an annular core and a secondary coil consisting of two or more winding groups, an annular primary coil winding frame is provided to cover the annular core. partitioning protrusions of the same number as the winding group of the secondary coil or an integral multiple thereof so as to protrude in the direction of the central axis of the primary coil winding frame at equal intervals on the outer surface of the primary coil winding frame. The primary coil is wound by winding the primary coil with an equal number of turns between the protrusions, and by sandwiching the protrusions from the front and back in the direction of the central axis of the primary coil winding frame. A pair of secondary coil winding frames are provided for positioning, and the secondary coils are arranged on the pair of secondary coil winding frames at equal intervals with the same number of turns, and the secondary coils are arranged at equal intervals between the secondary coils. A correction coil is wound approximately at the center with approximately the same number of turns, and the primary coil wound on the primary coil winding frame is housed inside the pair of secondary coil winding frames. . A magnetic sensor characterized in that the direction of the input axis of the secondary coil is corrected by connecting the correction coil to the secondary coil as necessary.