JPH06180207A - Rotary angle detector - Google Patents

Abstract

PURPOSE:To provide a rotary angle detector which obtains a high S/N ratio and at the same time is strong against turbulence of external magnetic field etc. CONSTITUTION:Four projecting electrodes are provided at the outer periphery of a rotar 2 and at the same time four recessed electrodes corresponding to the projecting electrodes of the rotar 2 are provided inner periphery of a stator 20. Further, eight stages of stator plates 4-11 which are laid out in the axial direction of the rotar 2 one another are provided and coil windings 13 and 16 for excitation and coil windings 12, 14, 15, and 17 for detection are wound at 8 stages of stator plates 4-11 in a sandwich in axial direction of the rotar 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle detecting device for electromagnetically detecting the rotation angle of a rotating body.

[0002]

2. Description of the Related Art As an example of a conventional rotation angle detecting device of this type, as shown in FIG.
The structure disclosed in the publication is known. This rotation angle detecting device includes primary windings 32A, 32B, 32 for excitation.
Excitation magnetic poles 33A and 33 in which C and 32D are differentially wound.
A plurality of pairs of B, 33C and 33D are provided at a predetermined angular interval in the circumferential direction, and a stator 35 provided with a secondary winding 34 for detecting the induced voltage by the excitation magnetic poles 33A to 33D, and a stator 35 of each stator. A rotor 36 having a shape that changes the reluctance of a magnetic path passing through the exciting magnetic poles 33A to 33D in accordance with a rotation angle, and a plurality of AC signals 37 having a phase shift corresponding to each exciting magnetic pole pair, 38
The secondary winding 34 is configured to output an AC signal having a phase shift corresponding to the rotation angle of the rotor 36.

[0003]

In the conventional rotation angle detecting device, the exciting windings 32A to 32D and the detecting winding 34 are wound around the common exciting magnetic poles 33A to 33D of the stator 35. Therefore, there is a problem that the structure is complicated, a high S / N ratio cannot be obtained due to the influence of self-inductance, and the structure is weak against a disturbance such as an external magnetic field.

The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a rotation angle detecting device which obtains a high S / N ratio and is strong against a disturbance such as an external magnetic field. It is a thing.

[0005]

In order to achieve the above object, the present invention is directed to a stator provided with an exciting magnetic pole having an exciting winding and a detecting winding for extracting an induced voltage by the exciting magnetic pole, and an exciting magnetic pole. In a rotation angle detection device including a rotor having a shape that changes the reluctance of a magnetic path passing through a pole according to a rotation angle, the rotor is provided with a plurality of salient poles, and the stator is provided with a plurality of salient poles of the rotor. A plurality of corresponding concave poles and multi-stage stator plates arranged in the axial direction of the rotor are provided, and the excitation winding and the detection winding are wound around the multi-stage stator plate in a sandwich shape in the axial direction of the rotor. It is characterized by that.

Another aspect of the present invention is characterized in that the detection winding comprises a combination of a plurality of windings connected in series so as to have a positive phase and an opposite phase with respect to the excitation winding. It is a thing.

[0007]

According to the first aspect of the present invention, the stator is provided with the plurality of concave poles corresponding to the plurality of rotor salient poles, and the multi-stage stator plates are arranged in the axial direction of the rotor. Since the exciting winding and the detecting winding are wound around the stator plate in a sandwich shape in the axial direction of the rotor, the exciting winding and the detecting winding are not the same exciting magnetic pole but different positions. It is separated and wound. Therefore, a high S / N ratio can be obtained with a simple structure.

According to the second aspect of the present invention, by combining a plurality of windings connected in series so that the detection winding has a positive phase and an opposite phase with respect to the excitation winding. ,
It is possible to strengthen against external disturbances such as an external magnetic field, and stable detection can be performed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a top view and a half cross-sectional view showing an embodiment of a rotation angle detection device of the present invention, in which 1 is a case made of a magnetic material, 2 is arranged in the case 1 and is rotatable by a rotary shaft 3. The rotor is supported and provided with, for example, four salient poles on the outer circumference. Reference numeral 20 denotes a stator provided on the inner circumference of the case 1, for example, 8 stages of stator plates 4, 5, 6, 7, 8, 9, 1 arranged in multiple stages in the axial direction of the rotating shaft 3.
The stator plates 4 to 11 are provided with four concave poles corresponding to the convex poles of the rotor 2.

With respect to the relative angles of the stator plates 4 to 11, the stator plates 4 and 6 are attached to the inner circumference of the case 1 at the same angle, and the stator plates 5 and 7 are referenced with this position as a reference.
Is a mechanical angle M of 45 °, an electrical angle E of 180 °, the stator plates 8 and 10 are a mechanical angle M of 22.5 ° and an electrical angle E of 90 °, and the stator plates 9 and 11 are a mechanical angle. 67.5 ° at M and 270 ° at electrical angle E. 12, 14, 15, 17 are windings for detection, 1
Reference numerals 3 and 16 denote exciting windings, which are arranged concentrically with respect to the axis of the rotor 2 on each of the stator plates 4 to 11 as shown in FIGS.

Further, as shown in FIG. 3, the excitation winding 1
3, the detection winding 12 is in the positive phase and the detection winding 14 is
Are wound in a reverse phase, the detection winding 15 is wound in a positive phase and the detection winding 17 is wound in a reverse phase with respect to the excitation winding 16, and each of the detection windings 12, 14, 15 is wound. , 17 are connected in series with each other to form a detection winding group 18. Here, an AC signal (A phase) of Sinθ is applied to the excitation winding 13 as an excitation signal, and a Co signal is applied to the excitation winding 16.
An AC signal (B phase) of sθ is added as an excitation signal.

With such a structure, the rotor 2 is mechanically angled from the state of FIG. 1 at mechanical angles M of 0 °, 22.5 °, 45 ° and 6 °, respectively.
When it is rotated at 7.5 °, the excitation windings 13 and 16 respectively
When the excitation signals of Sinθ and Cosθ are added, each detection winding 1
Signals such as those shown in FIG. 4 are induced in 2, 14, 15, and 17, and the combined rotor 2 is detected from the detection winding group 18.
A signal with a phase shift corresponding to the mechanical angle (rotation angle) of is generated.

FIG. 5 shows the positional relationship of the windings 12 to 17 wound around the stator plates 4 to 11 of the stator 20 arranged to face the rotor 2, or to the rotor 2 as described above. The position at the rotation angle is shown. FIG. 6 shows the structure of a part of FIG.
As shown in FIG. 7, the openings 2 to 17 are provided with an opening 19 in the center and are provided at desired positions of the stator plates 4 to 11. The rotor 2 is arranged in the opening 19. Reference numeral 21 denotes a magnetic path formed between each of the stator plates 4 to 11 of the stator 20 and the rotor 2.

According to this embodiment, the stator 2
0 is provided with four concave poles corresponding to the four convex poles of the rotor 2, and the stator plate 4 having eight stages in the axial direction of the rotor 2 is provided.
To 11 are provided, and excitation windings 13 and 16 and detection windings 12, 14, 15 and 17 are provided on these stator plates 4 to 11.
Is wound in the axial direction of the rotor 2, the windings 12 to 17 are separately wound at different positions of the stator 20. Therefore, the exciting windings 13 and 16 and the detecting windings 12, 14, 15 and 17 are not the common exciting magnetic poles of the stator as in the conventional case, but are separately wound at different positions of the stator 20. Therefore, the influence of self-inductance is eliminated, and a high S / N ratio can be obtained. Further, along with this, it is possible to strengthen against disturbance such as an external magnetic field. Further, since the stator 20 is constituted by eight stages of stator plates 4 to 11 provided in the axial direction of the rotor 2, the windings for excitation 13, 16 and the windings for detection 12, 14, 15, 17 are wound. Since it can be easily turned, it is excellent in mass productivity.

As another embodiment of the present invention, the winding 13 is used as a detection winding having a positive phase and a winding 16 having a reverse phase, while the windings 12, 14, 15, 17 are used. Can also be realized as a one-phase excitation two-phase detection method in which is used as an excitation winding. in this case,
The parts can be realized without having to add new ones. FIG. 8 shows the signal waveforms of the windings 12 to 17 in this embodiment, and the position detection is performed by comparing the amplitudes (voltages) of the windings 13 and 16. It should be noted that such a configuration can be realized even in the case of one pole (electrical angle = mechanical angle) to multiple poles simply by changing the rotor and the stator.

FIG. 9 shows another embodiment of the present invention, in which the rotor 2 and the stator 20 are provided with teeth to strengthen the magnetic coupling between them, and A is the rotor 2.
And a stator 20 with four teeth 2A to 2D and teeth 20A to 20D respectively, and B shows a single pole example with the rotor 2 and the stator 20 having teeth 2A and 20A respectively. In the case of a single pole, the electrical angle and the mechanical angle of the rotor 2 are equal.

In this embodiment, the case of four poles has been described as an example, but the number of poles is not limited to four, and an example in which the stator plates 4 to 11 constituting the stator 20 are provided in eight stages has been shown.
There is no limitation to the number of steps, and these can be appropriately changed according to the purpose, application and the like.

[0018]

As described above, according to the present invention, the stator is provided with the plurality of concave poles corresponding to the plurality of rotor salient poles and the multi-stage stator plates arranged in the axial direction of the rotor. Since the excitation winding and the detection winding are wound around the stator plate in a sandwich shape in the axial direction of the rotor, the windings can be separately wound at different positions on the stator, so that the high S It is possible to obtain the / N ratio and to be strong against a disturbance such as an external magnetic field.

[Brief description of drawings]

FIG. 1 is a top view showing an embodiment of a rotation angle detection device of the present invention.

FIG. 2 is a half sectional view of FIG.

FIG. 3 is a connection diagram showing a connection relationship between an excitation winding and a detection winding used in this embodiment.

FIG. 4 is a waveform diagram of signals flowing in an excitation winding and a detection winding used in this embodiment.

FIG. 5 is a side view showing an arrangement relationship between a rotor and a stator in this embodiment.

FIG. 6 is an enlarged view showing the structure of a part of FIG.

FIG. 7 is a perspective view showing the appearance of each winding used in FIG.

FIG. 8 is a waveform diagram of signals flowing in an excitation winding and a detection winding according to another embodiment of the present invention.

FIG. 9 is a top view showing a positional relationship between a rotor and a stator in another embodiment of the present invention.

FIG. 10 is a top view showing an arrangement relationship between a rotor and a stator and a connection relationship between an excitation winding and a detection winding wound around the stator in a conventional example.

[Explanation of symbols]

 2 rotors 4 to 11 stator plate 12, 14, 15, 17 detection winding 13, 16 excitation winding 18 detection winding group 19 opening 20 stator

Claims (2)

[Claims] 1. A stator comprising an exciting magnetic pole having an exciting winding and a detecting winding for extracting an induced voltage by the exciting magnetic pole, and a reluctance of a magnetic path passing through the exciting magnetic pole is changed according to a rotation angle. In a rotation angle detecting device having a shaped rotor, the rotor is provided with a plurality of salient poles, and the stator is provided with a plurality of recessed poles corresponding to the salient poles of the rotor and arranged in the axial direction of the rotor. With a multi-stage stator plate,
A rotation angle detecting device, wherein the excitation winding and the detection winding are wound around a multi-stage stator plate in a sandwich shape in an axial direction of a rotor. 2. The rotation according to claim 1, wherein the detection winding comprises a combination of a plurality of windings connected in series so as to have a positive phase and an opposite phase with respect to the excitation winding. Angle detection device.