JP2011069811A - Rotation angle sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation angle sensor capable of preventing reduction of yields, abolishing the use of expensive and complicated coilers, and reducing the tact time by individually forming yokes, and suppressing output errors that occur while the sensor is driven by forming closed magnetic circuits. <P>SOLUTION: This rotation angle sensor 1 includes: a rotor 10, formed of a magnetic body around which no windings are wound, having N salient poles or a sinusoidal gap permeance of N cycles; and a plurality of magnetic pole units 20, each including a yoke 21 and an exciting coil 23 and either a first output coil 24a or a second output coil 24b wound around the yoke 21, disposed around the rotor 10. The magnetic units 20 form independent closed magnetic circuits. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotation angle sensor.

  A sensor having a plurality of coils in which three types of windings are wound inward so as to surround the outer periphery of the magnetic rotor is arranged, and the change in the gap between the rotor coils due to the rotation of the rotor is converted into a SIN voltage output. In this sensor, a technique is disclosed in which the number of coil turns wound around the stator is arranged on the SIN distribution and mechanical winding is enabled (for example, see Patent Document 1).

  Further, a technique is disclosed in which the winding process is simplified by making the number of turns of the output coil the same as in Patent Document 1 (see, for example, Patent Document 2).

Japanese Patent No. 3104487 JP 2004-251733 A

  However, in Patent Document 1 and Patent Document 2 of the prior art, an inner circumference on which a rotor is arranged to form a stator including a magnetic pole unit by stacking a plurality of stators formed by pressing from one electromagnetic steel sheet. Part of the electrical steel sheet was not used, resulting in a low yield. In addition, since a coil must be wound around each of the plurality of protrusions located on the inner periphery of the stator, a special winding machine is required, and at the same time, a complicated winding process is required. There was a problem of becoming longer. Further, since the stator outside the rotor is magnetically coupled, there is a problem in that magnetic field interference occurs between adjacent coils, resulting in an error in output.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotation angle sensor in which the yield of electromagnetic steel sheets is high, tact time can be shortened, and magnetic field interference is reduced.

  The first problem-solving means taken in order to solve the above-mentioned problems is that there are N salient poles or N cycles of sinusoidal gap permeance, a rotor made of a magnetic material, an excitation coil, and a COS output. A rotation angle sensor comprising: a first output coil to be obtained and at least one of a second output coil to obtain a SIN output directly or indirectly wound around a yoke, and a plurality of magnetic pole units arranged around the rotor The magnetic pole unit forms an independent closed magnetic circuit.

  The second problem solving means has N salient poles or N cycles of sinusoidal gap permeance, obtains a rotor made of a magnetic material, an excitation coil, a first output coil for obtaining COS output, and a SIN output. A rotation angle sensor including a plurality of magnetic pole units that are wound around the yoke directly or indirectly around at least one of the second output coils, and the magnetic pole unit is a non-rotating sensor. It is fixed to a magnetic body.

  A third problem solving means is that the yoke has a U-shape.

  A fourth problem solving means is that the magnetic pole unit is arranged so that the U-shaped opening of the yoke faces the rotor.

  A fifth problem solving means is that the exciting coil, the first output coil, and the second output coil are wound around a U-shaped bent portion of the yoke.

  The sixth problem solving means is that the number of turns of the first output coil and the second output coil is the same.

  A seventh problem solving means is that the magnetic pole unit is arranged at a constant distance from the rotation axis of the rotor.

  The eighth problem-solving means is that the rotor does not have a winding, and (N × Y) magnetic pole units are arranged.

  According to the present invention, since the rotation angle sensor of the present invention is composed of a plurality of individual magnetic pole units, it is possible to increase the yield of the electrical steel sheet that constitutes the yoke that constitutes the magnetic pole unit. In addition, since the magnetic pole units are independent, each magnetic pole unit forms an independent closed magnetic path, magnetic field interference to adjacent magnetic pole units is reduced, and the rotation angle detection accuracy is improved.

  Moreover, the yield of the electromagnetic steel plate which comprises a yoke can be improved by providing several magnetic pole unit independently. Since the magnetic pole unit is fixed to the non-magnetic material, each magnetic pole unit forms an independent closed magnetic path, magnetic field interference to the adjacent magnetic pole unit is reduced, and the rotation angle detection accuracy is improved.

  Further, since the yoke has a U-shape, the exciting coil and the output coil can be wound up by rotating the yoke without using a special winding machine. In addition, the coil wire supply tension and the feed pitch in the axial direction can be accurately set during winding, and aligned winding with stable coil space factor is possible. As a result, output fluctuations due to variations in the coil space factor are reduced, and the rotation angle detection accuracy is improved.

  Further, since the magnetic pole unit is disposed so that the U-shaped opening of the yoke faces the rotor, the gap between the both ends of the U-shaped yoke and the rotor changes, and the first The rotor angle can be detected by comparing the two outputs of the COS waveform and the SIN waveform generated in the output coil and the second output coil.

  Further, since the exciting coil, the first output coil, and the second output coil are wound around the U-shaped bent portion of the yoke, the yoke is rotated without using a special winding machine. One output coil and the second output coil can be wound up. In addition, the coil wire supply tension and the feed pitch in the axial direction can be accurately set during winding, and aligned winding with stable coil space factor is possible. Therefore, the impedance generated from the coil when the rotation angle sensor is driven is reduced, and the output is improved.

  In addition, since the number of turns of the first output coil and the second output coil is the same, it is possible to simultaneously wind the output coil around the yoke around which the first output coil is wound and the yoke around which the second output coil is wound. , Tact time is reduced.

  In addition, since a plurality of independent magnetic pole units are arranged at a certain distance from the rotation axis of the rotor, the yield of electromagnetic steel sheets can be increased. In addition, since the magnetic pole units are independent, each magnetic pole unit forms an independent closed magnetic path, magnetic field interference to adjacent magnetic pole units is reduced, and the rotation angle detection accuracy is improved.

  In addition, the rotor has no winding, and (N × Y) magnetic pole units are arranged to increase the yield of the electromagnetic steel sheet. In addition, since the magnetic pole units are independent, each magnetic pole unit forms an independent closed magnetic path, magnetic field interference to adjacent magnetic pole units is reduced, and the rotation angle detection accuracy is improved.

It is a block diagram of the rotation angle sensor in this invention. It is a block diagram of the magnetic pole unit in this invention. It is AA sectional drawing of the magnetic pole unit in this invention. It is a wiring diagram of each coil in the present invention. It is an example of the output result of the rotation angle sensor in this invention. It is a block diagram of the rotation angle sensor in a conventional structure. It is a graph of the result of having performed magnetic field analysis to the rotation angle sensor in the conventional structure. It is a graph of the result of having performed magnetic field analysis to the rotation angle sensor in the present invention.

  Hereinafter, the present embodiment will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a rotation angle sensor 1 according to the present invention. The rotation angle sensor 1 according to the present embodiment has N salient poles or N cycles of sinusoidal gap permeance, and obtains an elliptical rotor 10 made of a magnetic material, an excitation coil 23 and a COS output. At least one of the first output coil 24a and the second output coil 24b for obtaining the SIN output is wound around the yoke 21, and (N × Y) (Y is 4) at a fixed distance from the rotation axis of the rotor 10. The above-described integer) magnetic pole unit 20 is provided. That is, the magnetic pole unit 20 is disposed around the rotor 10 (outside of the outer periphery of the rotor 10).

  In this embodiment, since N = 2 and Y = 4, the number of magnetic pole units 20 to be arranged is eight. However, by changing the number of N and Y, the shape of the rotor 10 and the number of magnetic pole units 20 can be changed. It is possible to design by changing. Moreover, since the number of magnetic pole units increases as the value of Y increases, the output accuracy also improves. The same effect can be obtained even when the winding is wound directly on the yoke 21 or when the winding is wound indirectly on the outer periphery of the bobbin by covering the yoke 21 with a bobbin made of a resin material. Further, when both the first output coil 24a and the second output coil 24b are wound around the yoke 21 and the exciting coil 23, when only the first output coil 24a is wound, only the second output coil 24b is wound. The same effect can be obtained even when turned. The plurality of magnetic pole units 20 may be arranged so as to be detachable at a certain distance from the rotation axis of the rotor 10 on the outer circumference of the rotor 10, or may be arranged in a fixed state. . In addition, as a fixing method of the stopper 25, a method of fixing with a screw or a nut using a hole, a method of fitting the stopper 25 into a member to be fixed, and the like are used.

  FIG. 2 is a configuration diagram of the magnetic pole unit 20 in the present invention. The magnetic pole unit 20 used in the present invention includes a U-shaped yoke 21 and a coil 22 (excitation coil 23 and first output coil 24a (or second output coil 24b) wound around a bent portion 27 of the yoke 21. ) And a stopper 25 at the end of the yoke 21. As shown in FIG. 4, the magnetic pole unit 20 is arranged so that the opening 26 faces the rotor 10 by the fixing method of the stopper 25 described above. The yoke 21 of this embodiment has a configuration in which twelve pressed electromagnetic steel plates are stacked and integrated by welding or the like. In this embodiment, the shape of the yoke 21 is expressed as a U-shape, but the U-shape includes shapes such as a C-shape, a U-shape, and a horseshoe shape.

  FIG. 3 is an AA cross-sectional view of the magnetic pole unit 20 in the present invention. First, the exciting coil 23 is wound around the bent portion 27 of the yoke 21, and the first output coil 24a (or the second output coil 24b) is wound thereon. Table 1 shows an example of the number of windings and the winding method of the exciting coil 23 and the first output coil 24a (or the second output coil 24b) wound around each yoke 21.

  In Table 1, the yoke names (A) to (H) correspond to (A) to (H) in FIG. The minus notation in Table 1 means reverse winding with respect to the winding direction of the coil at the number of turns not represented by minus. “COS” and “SIN” of “number of output coil turns” in Table 1 mean so-called “COS winding” and “SIN winding”, respectively. In this embodiment, the first output for obtaining COS output, respectively. The coil 24a corresponds to the second output coil 24b that obtains the SIN output.

Note that the number of turns of the coil may be distributed so that the induced electromotive force distribution is a sinusoidal distribution (the number of turns of the coil is also a sinusoidal distribution). The same effect as the embodiment can be obtained.

  FIG. 4 is a wiring diagram of the exciting coil 23, the first output coil 24a, and the second output coil 24b in the present invention. The exciting coil 23 is electrically connected in series. Further, each of the plurality of magnetic pole units 20 and the yoke 21 in FIG. 4 will be described with reference numerals (A) to (H) as shown in FIG. The first output coil 24a wound around each of the yoke 21 (C), the yoke 21 (E), the yoke 21 (G), and the yoke 21 (A) is electrically connected in series as shown in FIG. Similarly, the second output coil 24b wound around each of the yoke 21 (B), the yoke 21 (D), the yoke 21 (F) and the yoke 21 (H) is also electrically connected in series as shown in FIG. The

  FIG. 5 is an example of the output result of the rotation angle sensor in the present invention. FIG. 5 (I) shows an example of the output result by the first output coil 24a, and FIG. 5 (II) shows an example of the output result by the second output coil 24b. The horizontal axis represents the rotation angle θ of the rotor 10, and the vertical axis represents the voltage value V obtained from the first output coil 24a and the second output coil 24b.

  Next, the operation of the present invention will be described.

  In the above configuration, a sine wave voltage of 10 kHz, 10 V, for example, is excited in the exciting coil 23. As the rotor 10 rotates, the gap between the rotor 10 and the yoke 21 of the magnetic pole unit 20 arranged at a certain distance from the rotation axis of the rotor 10 changes. Then, the magnetic resistance of the yoke 21 changes, and the output voltage generated in the first output coil 24a and the second output coil 24b changes in a sine wave shape. Since the first output coil 24a and the second output coil 24b are arranged with a 45 ° change in mechanical angle, this structure having a shaft angle multiplier of 2X outputs with a phase change of 90 ° as shown in FIG. . Thereby, the angle of the rotor 10 can be detected by comparing the two outputs of the obtained COS waveform and SIN waveform.

  Here, the conventional structure and the magnetic field analysis result of the present invention will be described.

  FIG. 6 shows a rotation angle sensor 30 having a conventional structure. The rotor 40, the stator 50, and 14 magnetic pole units 51 protruding from the inner periphery of the stator 50 are provided. Each position will be described with reference numerals (a) to (n). The magnetic pole unit 51 includes a coil 52 that is an excitation coil 53 and at least one of a first output coil 54a and a second output coil 54b.

  FIG. 7 is a graph showing a result of magnetic field analysis performed on the rotation angle sensor 30 in the conventional structure of FIG. The analysis was performed by winding the coil 52 only around the magnetic pole unit 51 (g). The horizontal axis indicates the magnetic pole unit, and the vertical axis indicates the interlinkage magnetic field. Since the magnetic pole unit 51 is magnetically connected to the stator 50, there is about 8% magnetic flux leakage with respect to the magnetic pole unit 51 (f) and the magnetic pole unit 51 (h) adjacent to the magnetic pole unit 51 (g). It was. Further, the magnetic pole units 51 (a) to (n) as a whole had a magnetic flux leakage of about 52.4%.

  FIG. 8 is a graph showing a result of magnetic field analysis performed on the rotation angle sensor 1 according to the present invention. The analysis was performed by winding the coil 22 only on the magnetic pole unit 20 (D) in FIG. The horizontal axis indicates the magnetic pole unit, and the vertical axis indicates the interlinkage magnetic field. Since the magnetic pole unit 20 is magnetically independent, the magnetic flux leakage is suppressed to about 0.3% with respect to the magnetic pole unit 20 (C) and the magnetic pole unit 20 (E) adjacent to the magnetic pole unit 20 (D). I was able to. Moreover, the magnetic flux leakage could be suppressed to about 0.65% in the whole magnetic pole units 20 (A) to (H).

  By forming the magnetic pole unit 20 independently as in this embodiment, the yield of the electromagnetic steel sheet is increased and the cost can be reduced. Further, since the yoke 21 has a U-shaped shape, the coil 22 can be wound by rotating the yoke 21. In addition, the coil wire supply tension and the feed pitch in the axial direction can be accurately set during winding, and aligned winding with stable coil space factor is possible. As a result, output fluctuations due to variations in the coil space factor are reduced, and the rotation angle detection accuracy is improved. In addition, since the winding method of the coil 22 is two types, the forward direction and the reverse direction, and the number of windings is the same, at least one of the exciting coil 23 and the first output coil 24a or the second output coil 24b is connected to the plurality of yokes 21. On the other hand, since the same type of coil can be wound at the same time, the tact time can be shortened.

  In addition, as a member for fixing the plurality of magnetic pole units 20, a nonmagnetic metal such as aluminum or a nonmagnetic member such as resin can be used. By fixing to a non-magnetic member as described above, leakage of magnetic flux can be suppressed, and each magnetic pole unit 20 is magnetically independent. It becomes possible to prevent.

  In addition, the magnetic pole unit 20 is disposed so that the U-shaped opening 26 of the yoke 21 faces the rotor 10, and a gap between both ends of the U-shaped yoke 21 and the rotor 10 is provided. As a result, two outputs of a COS waveform and a SIN waveform are generated in the first output coil 24a and the second output coil 24b, respectively. The rotation angle of the rotor 10 can be detected by comparing and processing the COS waveform signal and the SIN waveform signal.

  Further, since the exciting coil 23, the first output coil 24a, and the second output coil 24b are wound around the U-shaped bent portion 27 of the yoke 21, as described above, the yoke 21 is not used without using a special winding machine. Is rotated to wind up the exciting coil 23, the first output coil 24a, and the second output coil 24b, whereby the exciting coil 23, the first output coil 24a, and the second output coil 24b can be wound around the yoke 21. it can.

DESCRIPTION OF SYMBOLS 1 ... Rotation angle sensor 10 ... Rotor 20 ... Magnetic pole unit 21 ... Yoke 23 ... Excitation coil 24a ... First output coil 24b ... Second output coil 26 ... Opening Part 27 ... Bent part

Claims (8)

A rotor having N salient poles or N cycles of sinusoidal gap permeance and made of a magnetic material;
A magnetic pole unit that is arranged around the rotor, wherein the exciting coil and at least one of the first output coil that obtains the COS output and the second output coil that obtains the SIN output are directly or indirectly wound around the yoke; ,
A rotation angle sensor comprising:
The rotation angle sensor, wherein the magnetic pole unit forms an independent closed magnetic path. A rotor having N salient poles or N cycles of sinusoidal gap permeance and made of a magnetic material;
A magnetic pole unit that is arranged around the rotor, wherein the exciting coil and at least one of the first output coil that obtains the COS output and the second output coil that obtains the SIN output are directly or indirectly wound around the yoke; ,
A rotation angle sensor comprising:
The rotation angle sensor, wherein the magnetic pole unit is fixed to a non-magnetic material. The rotation angle sensor according to claim 1, wherein the yoke has a U shape. The rotation angle sensor according to claim 3, wherein the magnetic pole unit is disposed such that a U-shaped opening of the yoke faces the rotor. 5. The rotation angle sensor according to claim 3, wherein the excitation coil, the first output coil, and the second output coil are wound around a U-shaped bent portion of the yoke. The rotation angle sensor according to any one of claims 1 to 5, wherein the first output coil and the second output coil have the same number of turns. The rotation angle sensor according to any one of claims 1 to 6, wherein the magnetic pole unit is disposed at a constant distance from a rotation axis of the rotor. The rotor has a configuration without windings,
The rotation angle sensor according to claim 1, wherein (N × Y) magnetic pole units are arranged.

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