JP3177796B2 - Rotating magnetic field detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a rotating magnetic field synchronized with the rotation of a rotating electric machine such as a motor.

[0002]

2. Description of the Related Art In general, this kind of rotating magnetic field detecting device is
For example, as shown in FIG.
A magnet ring 1 provided on the rotating side where the poles and S poles are alternately magnetized by eight poles, and a fixed side mounting with an electrical angle of 30 ° to each other so as to face the magnet ring 1 via a gap. The magnetic pole sensor 2 is composed of three Hall elements provided on the plate 5 (21, 22, 23). As shown in FIG.
The rotating magnetic field can be detected based on 1, V2, and V3.

[0003] Here, as shown in FIG.
Has a phase difference of 30 ° between the outputs V1, V2, and V3. By superimposing the outputs V1, V2, and V3, the rotating magnetic field can be detected at an interval t of 15 °. In the figure, T is a cycle of one rotation of the magnet ring 1.

In such a rotating magnetic field detecting device,
Misalignment of magnetized position of magnet ring 1, each magnetic pole sensor 2
Of the outputs V1, V2, and V2 of the magnetic pole sensor 2 due to factors such as variations in the characteristics of
The phase difference between V3 is shifted, and the detection accuracy of the rotating magnetic field is deteriorated.

For this reason, conventionally, the processing accuracy of each part is increased or a magnetic pole sensor having uniform characteristics is selected. However, the yield of products is deteriorated and mass productivity is deteriorated. .

[0006] Conventionally, the detection timing of the rotating magnetic field is adjusted by appropriately shifting the mounting position of each magnetic pole sensor in the circumferential direction so as to improve the detecting accuracy of the rotating magnetic field. 18340 gazette).

[0007]

The problem to be solved is that if the mounting position of the magnetic pole sensor itself is shifted in the circumferential direction in order to adjust the detection timing of the rotating magnetic field after assembling the device, the problem is that This means that the operation for changing the mounting position is complicated, and it is difficult to finely adjust the mounting position.

[0008]

According to the present invention, an N
A magnet ring provided on the rotating side where the poles and the south poles are alternately magnetized, and a plurality of magnetic pole sensors provided on the fixed side at a predetermined electrical angle to each other so as to face the magnet ring via a gap. In order to make it easy to fine-tune the detection timing of the rotating magnetic field after assembling the device, each magnetic pole sensor draws the magnetic flux of the magnet ring into its magnetic pole sensing part to detect the rotating magnetic field. A member for adjusting the timing is provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a rotating magnetic field detecting device according to the present invention is provided on a rotating side in which eight N poles and S poles are alternately magnetized so as to be equally spaced on a circumference. A magnetic pole sensor 2 (a magnetic pole sensor 2 comprising three IC-equipped Hall elements provided on the fixed-side mounting plate 5 at an electrical angle of 30 ° with each other so as to face the magnet ring 1 with a gap therebetween so as to face the magnet ring 1 via a gap. 21, 22, 23), a rotating magnetic field detection timing adjusting member 3 (31, 32, 33) provided on the front surface of each magnetic pole sensor 2, and a yoke provided on the back surface of each magnetic pole sensor 2. Member 4
(41, 42, 43).

Rotating magnetic field detection timing adjustment members 3 provided on the front surface of each magnetic pole sensor 2 are provided so as to draw the magnetic flux of the magnet ring 1 into their respective magnetic pole sensing portions. As shown in 3,
The rear end of the magnetic pole sensor side is used as a fulcrum P, and the front end is mounted on the mounting plate 5 so that the front end can be displaced by swinging left and right, and can be positioned at a predetermined position by screwing or bonding. It has become.

The yoke members 4 provided on the back of each magnetic pole sensor 2 can increase the number of magnetic fluxes passing through each magnetic pole sensor 2 by providing the yoke members 4, thereby stably detecting the rotating magnetic field. And it can be performed reliably.

With this configuration, as shown in FIG. 4, a rotating magnetic field can be detected based on the outputs V1, V2, and V3 of the magnetic pole sensors 2.

Here, each output V1, V of the magnetic pole sensor 2 is
2 and V3 is 30 °, and the output V
By superimposing 1, V2 and V3, the rotating magnetic field can be detected at an interval t of 15 °. In the figure, T
Is a cycle of one rotation of the magnet ring 1.

In such a rotating magnetic field detecting device,
As described above, the deviation of the magnetized position of the magnet ring 1, the variation of the characteristics of each magnetic pole sensor 2, the
The phase difference between the outputs V1, V2, and V3 of the magnetic pole sensor 2 is shifted due to factors such as a shift in the mounting position of the magnetic pole sensor 2, and the detection accuracy of the rotating magnetic field is deteriorated.

According to the present invention, the tip of the rotating magnetic field detection timing adjustment member 3 provided to draw the magnetic flux of the magnet ring 1 into the magnetic pole sensor of each magnetic pole sensor 2 is shown in FIG. 2 or FIG. As shown in the figure, the detection timing of the rotating magnetic field is adjusted by appropriately shaking to the left or right to shift, and the outputs V1, V
The phase difference between V2 and V3 is set to a predetermined value.

As shown in FIG. 2, the tip of the adjusting member 3 is swung in the direction opposite to the direction of rotation of the magnet ring 1 indicated by the arrow in the figure, so that the detection timing of the rotating magnetic field, that is, the output signal of the magnetic pole sensor 2, The phase can be delayed by a predetermined amount, and the detection timing of the rotating magnetic field can be advanced to a predetermined value by swinging the tip of the adjusting member 3 in the rotation direction of the magnet ring 1 as shown in FIG.

After the adjustment, the adjustment member 3 is positioned at a predetermined position by screwing or bonding.

As described above, according to the present invention, the tip of the rotating magnetic field detection timing adjusting member 3 is appropriately swung in the rotating direction of the magnet ring 1 or in the opposite direction without moving the position of each magnetic pole sensor 2 at all. Just by shifting, the detection timing of the rotating magnetic field can be finely adjusted.

Therefore, the deviation of the magnetized position of the magnet ring 1, the variation of the characteristics of each magnetic pole sensor 2, the characteristics of each magnetic pole sensor 2 without increasing the processing accuracy of each part or selecting magnetic pole sensors having uniform characteristics. Error factors such as displacement of the mounting position of the magnetic pole sensor 2 can be easily absorbed, and the rotating magnetic field can be detected with high accuracy.

Further, it is possible to adjust the detection angle of the rotating magnetic field without applying any mechanical stress to each magnetic pole sensor 2.

FIG. 5 shows another embodiment of the present invention. In this case, the adjusting member 6 for detecting the rotating magnetic field is slid left or right along the magnetic pole sensing surface of the magnetic pole sensor 2. It can be positioned appropriately.

FIG. 6 shows still another embodiment of the present invention. In this case, the magnetic pole sensor 2 is mounted on the mounting plate via the yoke member 4 so that the magnetic pole sensing surface faces upward. In addition, a plate-shaped rotating magnetic field detection timing adjusting member 8 is provided on the magnetic pole sensing surface so that the tip of the magnet ring side can be swung left and right to position.

FIG. 7 shows still another embodiment of the present invention. In this case as well, the magnetic pole sensor 2 is similarly mounted on the mounting plate via the yoke member 4 so that the magnetic pole sensing surface faces upward. Further, a rod-shaped rotating magnetic field detection timing adjusting member 9 is provided on the magnetic pole sensing surface so that the tip of the magnet ring side can be swung left and right to perform positioning.

[0024]

As described above, in the rotating magnetic field detecting device according to the present invention, the magnet ring provided on the rotating side, the N and S poles of which are alternately magnetized on the circumference, and the gap between the magnet ring and the magnet ring. A rotating magnetic field detecting device comprising a plurality of magnetic pole sensors provided on a fixed side with a predetermined electrical angle so as to face each other via a magnetic field. Can be adjusted to adjust the magnetized position of the magnet ring,
There is an advantage that it is possible to accurately detect the rotating magnetic field by absorbing error factors such as variations in the characteristics of the magnetic pole sensors and deviations in the mounting positions of the magnetic pole sensors.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a rotating magnetic field detection device according to the present invention.

FIG. 2 is a partial front view showing a state in which the tip on the side of the magnetic pole sensor is shifted to the left in the embodiment.

FIG. 3 is a partial front view showing a state in which the tip on the side of the magnetic pole sensor is shifted to the right in the embodiment.

FIG. 4 is a time chart of an output signal of each magnetic pole sensor.

FIG. 5 is a perspective view of a magnetic pole sensor part according to another embodiment of the present invention.

FIG. 6 is a perspective view of a magnetic pole sensor portion showing still another embodiment of the present invention.

FIG. 7 is a perspective view of a magnetic pole sensor portion showing still another embodiment of the present invention.

FIG. 8 is a front view showing a conventional rotating magnetic field detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Magnet ring 2 (21, 22, 23) Magnetic pole sensor 3 (31, 32, 33) Rotation magnetic field detection timing adjustment member 4 (41, 42, 43) Yoke member 5 Mounting plate 6 Rotation magnetic field detection timing adjustment member 8 Adjustment member for rotating magnetic field detection timing 9 Adjustment member for rotating magnetic field detection timing

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01D 5/00-5/62 H02K 11/00

Claims (2)

(57) [Claims] 1. A magnet ring provided on a rotating side, on which a north pole and a south pole are alternately magnetized on a circumference, and a predetermined electrical angle to each other so as to face the magnet ring via a gap. In a rotating magnetic field detection device including a plurality of magnetic pole sensors provided on a fixed side, each magnetic pole sensor is provided with a member that adjusts a timing of detecting a rotating magnetic field by drawing magnetic flux of the magnet ring into its magnetic pole sensing unit. A rotating magnetic field detection device characterized by the above-mentioned. 2. The rotating magnetic field detecting device according to claim 1, wherein a yoke member is provided on a back surface of the magnetic pole sensing unit in each magnetic pole sensor.