JPS6026451A - Frequency generator of servo motor or the like - Google Patents

Abstract

PURPOSE:To obtain an accurate rotating frequency output by varying the number of one variation of periodic magnetic frequencies in poles of a drive multipolar magnet to 2n times. CONSTITUTION:A frequency generator is formed of a drive multipolar magnet 1' having an irregular portion and a generating coil 5' having generating strands 4'a, 4'b for detecting a periodic change of a magnetic flux. A radial slot 2' is formed on the magnetizing surface of this magnet 1'. In this case, the magnet 1' is formed with slots at an equal pitch so that periodic variations in the magnetic flux of 2n times (n=1,2,...) occur in one pole together with the slots 2', and 180 deg. of an electric angle is displaced to the pitch in the adjacent pole with the boundary of the pole as a reference. Thus, the voltages induced at the strands 4'a, 4'b cancel to each other in the boundary, and only the voltage except the boundary is outputted as a rotating frequency output.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is comprised of a driving multi-pole magnet having grooves that cause periodic changes in magnetic flux, and a power generation coil consisting of a power generation line element in which a voltage is induced by the change in magnetic flux. This invention relates to a frequency generator such as a servo motor that detects a frequency output according to the frequency.

Generally, in servo motors, etc., the frequency generator detects the rotational frequency of the servo motor and converts it into voltage (F
-V conversion), and the rotational speed of the motor is controlled by using the electric current aE as the rotational speed control voltage.

Figure 1 shows an example of a frequency generator consisting of a driving multi-pole magnet having an uneven portion that causes periodic changes in magnetic flux, and a generating coil made of a generating line element that detects the magnetic flux portion. It is something that

In Figure 1, 1 is the distance between the N pole part and the S rest part in the circumferential direction υ
1 is a magnetized multi-polar magnet for driving, 2 is a radial groove provided on the magnetized surface of the multi-polar magnet to cause periodic magnetic flux changes, and 6 is a magnetic pot fixed to the multi-polar magnet 1. 4 is a power generation line element arranged in one-to-one correspondence with the change in magnetic flux caused by the groove 2 and detects the change in magnetic flux; 5 is a power generation coil composed of the power generation line element 4; , a multipolar magneto 1 concentrically with this generating coil 5
-2 and the rotor rotate, the power generation line element 4
A change in magnetic flux occurs above, and a voltage is induced in the power generating line element 4, which is integrated all around and detected by the power generating coil 5 as a rotational frequency. The magnetic flux change at this time is generally 2n+1 (n=1
．． 2.3...) times, the operation of the device shown in FIG. 1 will be explained in detail using FIG. 2. Second
In the figures, (5) and (13j are developed views in the circumferential direction of the groove portions 2 in the generating coil 5 and the multipolar magnet 1, ((-
1 is a diagram illustrating the change in magnetic flux passing through each power generation line element 4 in the power generation coil 5 in a simplified manner and replacing it with a switching operation. In (5) of Fig. 2, the direction of -induced VtE is indicated by ■ (direction from the front to the rear of the paper) or ■ (direction from the rear to the front of the paper). The grooves are equally pinched so as to cause 10 periodic magnetic flux changes within one magnetic pole.
t'' is cut, and the phase is shifted by 180 degrees in electrical angle with respect to the pinch l- with respect to the boundary of one magnetic pole as a reference. Magnetic flux change is based on one magnetic pole, and reversal of magnetic poles is also a change in magnetic flux. In this case, it will be 11 times.

Since there is a one-to-one correspondence between the magnetic flux change and the emitting element, when the multipolar magnet 1 rotates in the direction of the arrow, Fleming's right-hand rule causes the emitting element 4 to change as shown in Figure 2. A voltage is induced in the direction indicated by Al, and this induced voltage is output as a rotational frequency output.

However, in terms of accuracy, it is difficult to completely align the center of the groove 2 with the center of rotation of the multipolar magnet 1 and the center of the power generation coil.

Hereinafter, it is assumed that the center of the groove, the center of rotation of the multipolar magnet, and the center of the power generation coil are each slightly shifted from each other. Also, if we pay attention to the magnetic flux change corresponding to the above-mentioned boundary part, the magnetic flux change in this part is similar to that of the groove part 2 of the multipolar magnet, as shown by (Q OJ C+, C2 in Fig. 2). Therefore, under the above-mentioned premise, there is a possibility that the center of the multi-polar magnetization of the multi-polar driving magnet 1 deviates from the center of rotation of the rotor, or that the magnetization becomes uneven. If the accuracy is poor, the above C
The induced voltage due to the magnetic flux change at I+02 is directly applied to the output of the coil 5 at the source 1. Furthermore, if there is a slight overall phase shift between the boundary between the N and S poles of the driving multi-pole magnet l-1 and the groove 2, this may cause modulation in the output of the power generating coil 5. This has the disadvantage that it becomes easy to bend.

The above-mentioned drawbacks become more severe as each accuracy gets worse, and if the accuracy cannot be improved to 9, it becomes a big drawback.1. Mau.

The present invention has been made to eliminate the above-mentioned drawbacks.
By setting the number of strokes of periodic magnetic flux changes in one magnetic pole of the driving multi-pole magnet to 2n (n-1, 2, 3...) times - accurate rotation even under conditions with a certain degree of precision It is an object of the present invention to provide a frequency generator capable of obtaining frequency output.

Hereinafter, the operation of an embodiment of the present invention will be explained using the drawings.

In FIG. 3, (Al and (13) are the generator coil 5'
and a developed diagram in the circumferential direction of the multipolar magnet 1',
It is a diagram shown in place of a switching operation. In addition, 2
' is a groove provided radially on the magnetized surface of the multipolar magnet 1'. As is clear from (13) in Figure 3,
The above-mentioned multi-pole magnet 1', together with the full part 2', has grooves cut with equal pinches so as to bring about 12 periodic magnetic flux changes (n=6) within one magnetic pole, and are adjacent to each other with reference to the boundary between the magnetic poles. At the magnetic pole, the phase b' in electrical angle is
-180' shift. Now, this multipolar magnet 1
' is rotating in the direction of the arrow, and if we pay attention to the generating line element 4'a located at the boundary of the magnetic poles, this generating line element 4'a will advance from the S pole to the N pole. Because it is the moment to
The direction of change in magnetic flux is defined as the upward direction in the drawing, and the direction of movement of the conductor (starting coil 5') obtained relative to the direction of rotation of the multipolar magnet 1 shown by the arrow is defined as the rightward direction in the drawing. When the law is applied, the direction of the voltage induced in the power generating line element 4'a is from the front to the rear in the drawing. Also, the power generation line element 4'b, which is a part of the power generation coil 5' located at the other boundary of the magnetic poles.
If we pay attention to this, this is the moment when the power generation line element 4'b enters the S pole from the N pole, so if Fleming's right-hand rule is similarly applied, the voltage induced in the power generation line 4'b will be The direction is from the rear to the front in the drawing. Here, the direction of the voltage induced in the power generating line element 4'b and the voltage induced by the groove 2' of the multipolar magnet 1' other than the boundary between the magnetic poles are in the same direction in the power generating coil. , the above-mentioned frost formation; only the voltage induced in the line element 4'b is in the opposite direction. Therefore, if we focus only on the boundary between the magnetic poles, the voltage induced in the generating abrasive wire element 4'a and the voltage induced in the generating line element 4'b cancel each other out.
Only the voltage induced by the groove 2' of the magnet 1' other than the boundary between the magnetic poles, which mostly appears as an output, is output as a rotational frequency output, and the same can be said for the entire circumference. As described above, the present invention provides a driving multipolar magnet 1' which is dividedly magnetized in the circumferential direction and has a plurality of uneven parts formed by radial grooves 2' on the magnetization surface, and a driving multipolar magnet 1'. A power generation line element 4 is disposed at a position facing the uneven portion so as to correspond one-to-one to the change in magnetic flux due to the uneven portion.
In a frequency generator equipped with a generating coil 5' consisting of a generator coil 5', the uneven portion has a period of 2n (n=1.2.3...) times in a portion corresponding to one magnetic pole of the multipolar magnet 1'. 1. The structure is constructed so as to bring about a magnetic flux change, and the irregularities are shifted by 180 degrees with respect to the respective boundaries between the north and south poles of the multipolar magnet 1'.1. By doing so, the magnetic flux change is detected as a frequency change by the generating coil 5' and the rotational speed is controlled.
If the center of rotation of the multipolar magnet 1' is slightly deviated, the magnetization of the multipolar magnet 1' may be affected by the following:
The component superimposed on the rotational frequency signal due to the phase shift between the magnetic pole boundary and the groove 2' (voltage component induced in the power generation line by the magnetic pole boundary) can be canceled, resulting in accurate frequency power generation. We can provide equipment.

[Brief explanation of drawings]

Figure 1 is a configuration diagram showing an example of a frequency generator, and Figure 2 (
8 and (o) are circumferential development diagrams of the generating coil and multipolar magnet in the example shown in Figure 1, and (q in Figure 2) are changes in magnetic flux passing through the starting coil in the example shown in Figure 1. A simplified magnetic flux distribution diagram, Figure 6 (
In FIG. 6, (q) is a simplified diagram of the change in magnetic flux passing through the power generating line element in an embodiment of the present invention. Fig. 1 is a magnetic flux distribution diagram shown in Fig. 1. 1': multipolar magnet, 2': groove on the multipolar magnet, 4': generating line element, 5': generating coil.

Claims (1)

[Claims] A driving multi-polar magnet that is divided into magnets in the circumferential direction and has a plurality of uneven parts formed by radial grooves on the magnetized surface, and a driving multi-polar magnet having a plurality of uneven parts formed at positions facing the uneven parts of the multi-polar magnet. In a frequency generator equipped with a power generation coil made of power generation wire elements arranged in a one-to-one correspondence with changes in magnetic flux, the uneven portion has a 2n height in a portion corresponding to one sharpened pole of the multipolar magnet. (n=1.2.3...
) is configured to bring about a periodic change in magnetic flux, and the uneven portion is configured to have an electrical angle of 180°C with reference to each boundary between the N-pole portion and the S-pole portion of the multipolar magnet. Particularly, a frequency generator such as a servo motor, characterized in that the above-mentioned magnetic flux change is detected as a frequency change by the above-mentioned power generation coil, and the rotational speed is controlled.