JPH0553201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a method in which a first
A pair of stator coils is provided, and a second pair of stator coils is provided at symmetrical positions in the orthogonal direction to supply carrier waves with a phase difference of 90° to each other, and to the rotor coil located at the rotation axis. The present invention relates to a rotation angle detection device that induces a phase-modulated signal depending on the rotation angle.

[Problems to be solved by conventional technology and invention]

This type of rotational angle detection device is well known as a goniometer or a resolver. Usually, as shown in FIG. 5, the stator coil 2 is a ring-shaped bopin or toroidally wound around the core 1, and the rotor coil is wound around the center space of the stator coil 2. It was formed by arranging the coil 3. Therefore, not only the winding method but also the assembly was not easy and caused problems in terms of cost.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rotation angle detection device of the type mentioned at the outset, which is advantageous in terms of operation.

[Means for solving problems]

To achieve the above-mentioned purpose, each stator coil 5 may be wound on a plane parallel to the rotating shaft 6 as in the case of FIG. 5, as shown in FIGS. 6a and 6b, or a bobbin or core may be formed individually. It is also conceivable to wrap it around the outer periphery. However, the positioning of the rotor coil or the overall assembly is still not easy when considering the linearity of the phase modulation signal. Therefore, as shown in FIG. 1, the present invention connects a pair of stator coils 7, 7a and another pair of stator coils 8, 8a on a common plane normal to the rotation axis 0. each one of these
The opposing directions of the pair of stator coils were perpendicular to each other, and the stator coils were wound in the same shape around symmetrical positions at the same distance from the rotation axis 0. That is, winding was performed around each winding axis parallel to the rotation axis 0 at each symmetrical position.

On the other hand, the rotor coil 9 surrounds the rotation axis 0 in a plane normal to the rotation axis 0, and the winding center axis 0a is eccentric from the rotation axis, and the stator coils 7, 7a, 8, 8a are connected to each other. Wrapped so that they were facing each other.

[Effect]

The stator coils 7, 7a; 8, 8a are supplied with carrier waves sinωt and cosωt having different phases, and above or below the stator coils 7, 7a, a composite magnetic field φ1 and a stator coil are generated as shown in FIG. Composite magnetic field φ2 by 8, 8a is opposed (symmetrical)
occurs in the direction. That is, the composite magnetic field φ1 is a composite magnetic field of the magnetic fields of the stator coils 7 and 7a in mutually opposite directions. Therefore, when the winding center axis 0a of the rotor coil 9 coincides with the rotation axis 0, the induced electromotive force caused by the stator coils 7, 7a on both sides in the opposite direction is canceled out, but due to the eccentricity, the electromotive force generated by the stator coils 7 on both sides , 7a. As a result, an electromotive force is generated by the composite magnetic field φ1 corresponding to the rotation angle, and an electromotive force is similarly generated by the composite magnetic field φ2, thereby generating a phase-modulated signal sin(ωt+θ) by combining both electromotive forces.

[Embodiment of the invention] FIG. 2 shows a first embodiment of the invention.
The four stator coils 10a to 10d are multilayer cylindrical coils arranged around the four fan-shaped bobbins 11, orthogonal to each other, and centered at symmetrical positions at the same distance from the rotation axis 12. They are wound in the same shape. These stator coils of the same shape 1
Among the stator coils 0a to 10d, the same pair of opposing stator coils have their coil ends connected in series so as to generate magnetic fields in opposite directions with respect to the rotating shaft 12. The rotor coil 16 is a disk-shaped bobbin 15
The bobbin is wound as a circular coil around the bobbin, and the bobbin is eccentrically attached to a shaft 18 located on a rotating shaft 12 that projects downward from an upper case 17. 1 pair of opposing stator coils 10a,
10c are connected in series and supplied with a carrier wave sinωt, and the other 1 to 10 facing orthogonally
b and 10d are connected in series and are supplied with a carrier wave cosωt.

The area of the stator coil 10a facing the rotor coil 16 inputted by sinωt, that is, the area of magnetic coupling is S1, the facing area of the pair of stator coils 10c is S3, and the stator coil 10b inputted by cosωt. Let S2 be the facing area of the stator coils 10d, and S4 be the facing area of the pair of stator coils 10d, the voltage induced in the rotor coil 16 corresponds to the magnetically coupled areas S1 to S4, By combining the magnetic fields of these pairs in opposite directions, the induced voltage Eo induced in the rotor coil 16 is as follows.

Induced voltage Eo=S1sinωt−S3sinωt+S2cosωt−S4cosωt=(S1−S3)sinωt+(S2−S4)cosωt...(1) Here, the eccentric direction of the rotor 16 is exactly at the intermediate position of the stator coil 10a from the dotted line position shown in the figure. is
If the position rotated to the 45° rotation position is the reference position (rotation angle θ = 0), at this reference position the area S1 becomes the maximum and S3 becomes the minimum relative to the amount of eccentricity, and at this reference position, the area S1 - S3 becomes the maximum. become. Also, when the rotor coil 16 rotates 90 degrees from the reference position, S1, S3
have the same area, S1 - S3 = 0, and when rotated further to the 180° position, the magnitude relationship of S1 and S3 is reversed compared to the reference position, S1 - S3 becomes the maximum, and the polarity of sinωt changes. Invert. Furthermore, the magnitude of S1-S3 changes continuously within the range of change between these 90 degrees.

In other words, S1−S3 is S1− at the reference position of the previous surgery.
When S3=S, S changes in accordance with Scos θ as θ changes from the reference position. On the other hand, S2−S4
Since the stator coils 10b and 10d are deviated from the stator coils 10a and 10c by 90 degrees at the reference position, θ changes in accordance with sin θ as θ changes from the reference position. Therefore, the above equation (1) becomes as follows.

Induced voltage Eo=Scosθsinωt+Ssinθcosωt=Ssin(ω
t+θ) As a result, two orthogonal composite magnetic fields are induced in the rotor coil 16, and a rotation angle signal of sin(ωt+θ) is output corresponding to the rotation angle θ radian from the reference position. In addition, sin for the actual rotation angle θ
(ωt) phase linearity accuracy is rotor coil 1
6 and the structure and positional relationship of the stator coils 10a to 10d.

This sine wave signal is the reference sine wave signal.
It is amplified by amplifiers 21 and 22 together with sinωt and is made into a pulse, and at its edge, a flip-flop circuit 23
trigger. As a result, a pulse with a time width proportional to θ is obtained as the output, and the smoothing circuit 24
As the output, a DC signal with a level proportional to θ is obtained.

It has been experimentally confirmed that with such a configuration, good linearity of the phase modulation signal with respect to the rotation angle can be obtained. Further, it can be implemented for a servo type pen motor used in a pen recorder, for example, and in this case, the output signal of the smoothing circuit 24 becomes a servo error signal. Note that the stator and rotor coils 10 and 16 can also be formed as printed coils by laminating them in the direction of the rotating shaft 12. A core may be used instead of a bobbin instead of an air core.

FIG. 3 shows another embodiment, in which the stator coil 26 is wound in the same shape around a bobbin 27 having a square cross section at symmetrical positions orthogonal to each other at the same distance. On the other hand, the rotor coil 30 is wound around a disk-shaped bobbin 29 eccentrically attached to a shaft 28 disposed below the case above the center of these stator coil assemblies.

FIG. 4 shows yet another embodiment, in which a stator coil 36 is wound around a fan-shaped bobbin 37 in the same geometrical relationship as described above, and a shaft 38 is inserted into a hole 38a formed in the center. and is supported on the upper and lower case surfaces. A rotor coil 40 is wound around a disk-shaped bobbin 39 that is eccentrically attached to the shaft 38 below the stator coil 36.

〔Effect of the invention〕

As described above, according to the present invention, the stator coil does not need to be wound around the closed bobbin or the cross section of the core, and moreover, the winding area is divided radially around the rotation axis, and each coil is individually centered at a symmetrical position with respect to the rotation axis. can be simply and tightly combined for winding. In other words, it is extremely advantageous in terms of cost and shape while ensuring linearity.

[Brief explanation of the drawing]

Fig. 1a is a plan view of the principle of a rotation angle detection device according to the present invention, Fig. 1b is a schematic side view thereof, and Fig. 2a is a plan view and attached circuit of a rotation angle detection device according to an embodiment of the present invention. 2 and 2b are partially broken side views thereof, FIG. 3 is a plan view of the schematic configuration of the rotation angle detection device according to the second embodiment, and FIG. 4 is a rotation angle detection device according to the third embodiment. 5 is a plan view of the schematic configuration of a conventional rotation angle detection device, and FIGS. 6a and 6b are schematic perspective views of the rotation angle detection device that is the premise of the present invention, respectively. be. 7, 7a, 8, 8a, 10, 26, 36... Stator coil, 9, 16, 30, 40... Rotor coil, 18, 28, 38... Shaft, 0, 12... Rotating shaft, 0a... Winding center shaft.

Claims (1)

[Scope of Claims] 1. A first pair of stator coils occupying symmetrical positions with respect to the rotation axis on a common plane normal to the rotation axis of the rotor coil, and this pair of stator coils. and a second pair of stator coils that are perpendicular to the opposing direction of the stator coils and occupy symmetrical positions at the same distance as the symmetrical position with respect to the rotation axis, and fixing the first and second pairs of stator coils. In the rotation angle detection device, the rotation angle detection device is configured to induce a phase-modulated signal of the carrier wave in the rotor coil according to the rotation angle thereof by supplying carrier waves having a phase different by 90° to the child coil. Each pair of stator coils is wound in the same shape around the symmetrical position, and the rotor coil surrounds the rotation axis in a plane normal to the rotation axis, and the rotor coil surrounds the rotation axis in a plane normal to the rotation axis. The stator coils are wound eccentrically from the axis so as to face each of the stator coils, and the winding direction of each of the stator coils and the method of connecting each pair of stator coils to each other are determined with respect to the rotor coil. The rotation angle detecting device is characterized in that each pair of the stator coils is set to generate magnetic fields of the carrier waves having a phase difference of 90 degrees in mutually opposite directions.