JP2013083501A - Angle sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure reliability, and to improve productivity, concerning a structure of a pair of rotary transformer coils.SOLUTION: An angle sensor 1 is equipped with: a sensor rotor 7 including a rotor substrate 21 formed with a plane surface coil, and attached to a rotation shaft 14 through a rotor side annular metallic member 23 provided on an inner peripheral side of the rotor substrate 21; and a sensor stator 6 disposed oppositely to a surface of the sensor rotor 7, including a stator substrate 31 formed with a plane surface coil on a surface thereof, and provided with a stator side annular metallic member 35 on an inner peripheral side of the stator substrate 31. The rotor side annular metallic member 23 and the stator side annular metallic member 35 are respectively formed by magnetic material, and annular opposing portions 23c and 35a respectively opposing both the annular metallic members 23 and 35 are formed. In grooves 23d and 35b respectively formed on both the annular opposing portions 23c and 35a, rotary transformer coils 41 and 42 for signal transmission are respectively disposed.

Description

  The present invention relates to an angle sensor that detects a rotation angle of an output shaft of a motor or an engine.

  Conventionally, as this type of technique, for example, a sheet coil resolver described in Patent Document 1 below is known. This resolver includes two sheet coils in which a coil pattern is formed on the surface of a disk-shaped thin film substrate. The two sheet coils are arranged to face each other via a gap. Each of the two sheet coils includes a one-phase coil pattern in which a good conductor foil is formed in a spiral shape in which the winding direction is reversed at the center of the substrate, and a coil pattern formed in a spiral shape on the front and back of the thin film substrate. And a two-phase coil pattern arranged with an electrical angle shifted by π / 2. Outside the one-phase coil pattern, a transformer secondary pattern that supplies an excitation voltage to the one-phase coil pattern and a transformer primary pattern that has the same pattern as the transformer secondary pattern are separate from the two sheet coils. It is provided on the body and both patterns are arranged to face each other with a gap.

JP-A-9-229715

  Therefore, in the resolver described in Patent Document 1, each of the transformer secondary pattern and the transformer primary pattern is provided separately from the two sheet coils. Productivity was not good. Further, since the transformer secondary pattern and the transformer primary pattern are simply arranged to face each other with a gap between them, there is a risk of magnetic flux leaking between them, causing a detection error and in terms of reliability. There was a problem.

  The present invention has been made in view of the above circumstances, and the object thereof is to ensure reliability and improve productivity in relation to the configuration of a pair of coils for rotary transmission for signal transmission. It is to provide an angle sensor.

  In order to achieve the above object, an invention according to claim 1 includes an annular rotor substrate having a planar coil formed on a surface thereof, and a rotor-side annular metal member is provided on the inner peripheral side of the rotor substrate. Including a sensor rotor attached to the rotating shaft via a side annular metal member, a stator substrate having a surface opposed to the surface of the sensor rotor and having a planar coil formed on the surface, and a stator on the inner peripheral side of the stator substrate A rotor-side annular metal member and a stator-side annular metal member, each of which is formed of a magnetic material, with a gap between the rotor-side annular metal member and the stator-side annular metal member. The opposing ring-shaped opposing portions are formed, and a signal transmission rotary transformer coil is provided in each of the two annular facing portions.

  According to the configuration of the above invention, the sensor rotor is formed by integrally providing the rotor-side annular metal member formed of a magnetic material on the inner peripheral side of the rotor substrate, and the rotary metal is disposed on the annular facing portion of the annular metal member. A transformer coil is provided. Therefore, the rotor-side annular metal member that also serves as the core of the coil for the rotary transformer is used for attaching the sensor rotor to the rotating shaft. Further, a stator-side annular metal member formed of a magnetic material is integrally provided on the inner peripheral side of the stator substrate to form a sensor stator, and a rotary transformer coil is provided at an annular facing portion of the annular metal member. . Since the annular facing portion of the rotor-side annular metal member and the annular facing portion of the stator-side annular metal member face each other via a gap, the pair of rotary transformer coils face each other via the gap, and the magnetic flux generated therebetween Is formed between the two annular facing portions.

  In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, a groove is formed along the rotation direction in each of the two annular facing portions, and each groove is formed in each groove. The purpose is to arrange a coil for a rotary transformer.

  According to the configuration of the above invention, in addition to the action of the invention according to claim 1, the rotary transformer coil is surrounded by the groove of the annular facing portion, so that the magnetic flux generated in the rotary transformer coil can be reduced. The groove forms a magnetic closed circuit.

  According to the first aspect of the present invention, reliability can be ensured in connection with the configuration of the pair of coils for rotary transmission for signal transmission, and productivity can be improved.

  According to the second aspect of the invention, in contrast to the effect of the first aspect of the invention, leakage of magnetic flux can be suppressed between the pair of rotary transformer coils, and the SN ratio of the detection signal can be improved. Thus, noise resistance as an angle sensor can be improved.

The front sectional view showing an angle sensor and a motor to which it is attached according to the first embodiment. A sectional view showing an angle sensor concerning the embodiment. The top view which shows the sensor rotor which concerns on the embodiment and comprises an angle sensor. The top view which shows the sensor stator which concerns on the embodiment and comprises an angle sensor. FIG. 3 is an enlarged cross-sectional view of the angle sensor in the chain line circle of FIG. 2 according to the embodiment. The block circuit diagram which shows the electrical structure which concerns on the same embodiment and concerns on an angle sensor. The expanded sectional view according to FIG. 5 which concerns on 2nd Embodiment and shows a part of angle sensor.

<First Embodiment>
Hereinafter, a first embodiment in which an angle sensor according to the present invention is embodied will be described in detail with reference to the drawings.

  FIG. 1 is a front sectional view showing an angle sensor 1 and a motor 2 to which the angle sensor 1 is attached in this embodiment (hereinafter, the direction of FIG. 1 is a front view for convenience). The motor 2 includes a motor housing 11 having a substantially disk-shaped appearance, a rotary shaft 14 included in the motor housing 11 and supported rotatably via bearings 12 and 13 at the inner center thereof, A motor rotor 15 fixed on the outer periphery of the rotary shaft 14 on the inner side, and a motor stator 16 fixed on the inner side of the motor housing 11 via a gap on the outer peripheral side of the motor rotor 15 are provided. The motor stator 16 is provided with a coil 17.

  In FIG. 1, a housing portion 11 a for housing the angle sensor 1 is integrally formed on the lower side of the motor housing 11. The accommodating portion 11 a is configured by a substantially annular peripheral wall with the rotating shaft 14 and the bearing 13 as the center. A communication hole 11b communicating with the outside is formed in a part of the outer periphery of the housing portion 11a.

  As shown in FIG. 1, the rotating shaft 14 of the motor 2 has a substantially cylindrical shape, and includes a large diameter portion 14a and a small diameter portion 14b, and a step portion 14c at the boundary between the large diameter portion 14a and the small diameter portion 14b. The large diameter portion 14a is supported by one bearing 12, and the motor rotor 15 is fixed to the outer periphery thereof. The small diameter part 14b is supported by the other bearing 13, and the tip part protrudes outside from the shaft hole 11c formed in the bottom wall of the accommodating part 11a.

  As shown in FIG. 1, the angle sensor 1 includes a sensor stator 6 and a sensor rotor 7. The sensor rotor 7 is press-fitted into the outer periphery of the small-diameter portion 14 b of the rotating shaft 14 inside the motor housing 11 and is fixed by a ring-shaped stopper 8. The sensor stator 6 is disposed inside the housing portion 11 a of the motor housing 11 so as to face the sensor rotor 7 around the rotation shaft 14, and is fixed by a plurality of bolts 9 from the outside of the motor housing 11. The A plurality of elongated holes 11d through which a plurality of bolts 9 are inserted are formed in the bottom wall of the accommodating portion 11a. In this embodiment, a connecting member 10 having a substantially annular shape for integrally connecting the plurality of bolts 9 is interposed between the plurality of bolts 9 and the accommodating portion 11a.

  FIG. 2 is a sectional view of the angle sensor 1 of this embodiment (in FIG. 2, a fixing convex portion 33 described later is omitted). In FIG. 3, the sensor rotor 7 which comprises the angle sensor 1 of this embodiment is shown with a top view. In FIG. 4, the sensor stator 6 which comprises the angle sensor 1 of this embodiment is shown with a top view. As shown in FIGS. 1 to 3, the sensor rotor 7 includes a resin-made rotor substrate 21 having an annular flat plate shape, a planar coil 22 disposed on a surface 21 a of the rotor substrate 21, and an inner portion of the rotor substrate 21. A rotor-side annular metal member 23 that is provided integrally on the circumferential side and has a substantially annular shape that contacts the rotation shaft 14 in order to attach and fix the sensor rotor 7 to the outer periphery of the rotation shaft 14.

  The rotor substrate 21 is formed of PPS resin or the like. The rotor-side annular metal member 23 is made of a magnetic material such as iron. The planar coil 22 is formed on the surface 21a of the rotor substrate 21 by printing using an inkjet or the like, and an insulating layer is formed thereon. As shown in FIG. 3, the rotor-side annular metal member 23 includes one protrusion 23 a integrally formed on the inner periphery thereof, and a plurality of convex portions 23 b that are integrally formed on the outer periphery and project in the radial direction. Including. The plurality of convex portions 23b are formed radially at equiangular intervals. The metal member 23 is insert-molded with respect to the rotor substrate 21 at an outer peripheral portion including these convex portions 23b. Moreover, as shown in FIGS. 1-3, the rotor side cyclic | annular metal member 23 further contains the cyclic | annular opposing part 23c which protrudes in the axial direction from the surface side.

  As shown in FIGS. 1 and 2, the sensor rotor 7 is arranged so that the surface 21 a side of the rotor substrate 21 faces the surface side of the sensor stator 6, and is attached to the outer periphery of the small diameter portion 14 b of the rotating shaft 14. It is done. Here, the sensor rotor 7 is removed by the ring-shaped stopper 8 in a state where the inner periphery of the rotor-side annular metal member 23 is press-fitted into the outer periphery of the small-diameter portion 14b of the rotating shaft 14 and positioned at the stepped portion 14c. Stopped. Further, the protrusion 23 a of the rotor-side annular metal member 23 engages with a key groove (not shown) formed in the small diameter portion 14 b, and the sensor rotor 7 is prevented from rotating with respect to the rotating shaft 14. In this way, the sensor rotor 7 is fixed so as to be rotatable integrally with the rotary shaft 14.

  FIG. 4 is a plan view showing the sensor stator 6 of this embodiment. As shown in FIGS. 1, 2, and 4, the sensor stator 6 is formed of a resin in a substantially annular flat plate shape, and a stator substrate 31 having a planar coil 32 disposed on a front surface 31 a and a back surface of the stator substrate 31. A plurality of fixing projections 33 provided, an outer peripheral rib 34 formed along the outer peripheral edge on the back surface side of the stator substrate 31, extending in the axial direction, and formed at a central portion of the stator substrate 31, and the rotating shaft 14 Is formed along the inner peripheral edge of the through hole 31b on the back side of the stator substrate 31 and extends in the axial direction, and from the stator substrate 31 in the lateral direction (horizontal direction). And a single connector portion 36 facing toward each other. The stator side annular metal member 35 is formed of a magnetic material such as iron. In this embodiment, the stator side annular metal member 35 itself is an annular facing portion 35a that faces the annular facing portion 23c of the rotor side annular metal member 23 via a gap. The outer peripheral rib 34 and the plurality of fixing convex portions 33 are formed continuously and integrally. As shown in FIG. 4, the planar coil 32 disposed on the surface 31a of the stator substrate 31 is formed by printing using an inkjet or the like, and an insulating layer is formed thereon.

  As shown in FIGS. 1 and 2, each fixing projection 33 (only one is shown in FIG. 1) has a cylindrical shape, and in this embodiment, on the outer periphery of the back surface of the stator substrate 31. Are arranged at equiangular intervals. Each fixing projection 33 is provided with a metal bush 37 having a screw hole 37a. The metal bush 37 is insert-molded with respect to the fixing convex portion 33. The metal bush 37 is configured such that a bolt 9 is fastened to fix the sensor stator 6 to the motor housing 11.

  As shown in FIGS. 1 and 2, a plurality of metal terminals 39 are insert-molded in the connector portion 36. Each terminal 39 is formed to be bent at a right angle, the first end 39 a is disposed in the connector portion 36, and the second end 39 b is disposed on the stator substrate 31. A coil wire constituting the planar coil 32 is connected to each second end portion 39b arranged on the stator substrate 31, and a stator-side annular metal member 35 is connected thereto.

  FIG. 5 is an enlarged cross-sectional view of the angle sensor 1 in the chain line circle S1 of FIG. As shown in FIG. 5, the annular facing portion 23 c of the rotor-side annular metal member 23 and the annular facing portion 35 a of the stator-side annular metal member 35 are arranged to face each other with a predetermined gap. Coil 41,42 for rotary transformers is provided in the opposing surface of each cyclic | annular opposing part 23c, 35a. Specifically, grooves 23d and 35b are formed along the rotation direction in each of the annular facing portions 23c and 35a. Then, rotary transformer coils 41 and 42 are arranged in the grooves 23d and 35b, respectively. That is, the rotary transformer coils 41 and 42 are disposed so as to be surrounded by the grooves 23d and 35b.

  Next, an electrical configuration relating to the angle sensor 1 described above will be described. FIG. 6 is a block circuit diagram showing the electrical configuration of the angle sensor 1. As shown in FIG. 6, the angle sensor 1 is connected to the signal processing device 3. The angle sensor 1 includes a SIN signal exciting coil 46 and a COS signal exciting coil 47 that constitute the planar coil 32 of the sensor stator 6, a sensor coil 48 that constitutes the planar coil 22 of the sensor rotor 7, and a rotor-side annular shape of the sensor rotor 7. A rotary transformer coil 41 provided on the metal member 23 and a rotary transformer coil 42 provided on the stator side annular metal member 35 of the sensor stator 6 are included.

  As shown in FIG. 6, the signal processing device 3 includes an excitation signal generation circuit 51, a first detection circuit 55, a second detection circuit 56, and a calculator 57. The excitation signal generation circuit 51 outputs a high-frequency (480 kHz) excitation signal (SIN signal) to the rotary transformer coil 42. The first detection circuit 55 receives the SIN signal output from the SIN signal excitation coil 47. The second detection circuit 56 receives the COS signal output from the COS signal excitation coil 46. The computing unit 57 inputs the SIN signal and the COS signal output from the first and second detection circuits 55 and 56, respectively.

  In the signal processing device 3 described above, when an excitation signal is generated by the excitation signal generation circuit 51, the rotor-side sensor coil 48 passes through the stator-side rotary transformer coil 42 and the rotor-side rotary transformer coil 41. An excitation signal is input. An electromotive force (SIN signal and COS signal) is generated in the SIN signal excitation coil 47 and the COS signal excitation coil 46 on the stator side by the magnetic flux generated by the current of the excitation signal. By analyzing the amplitude fluctuation of the electromotive force (SIN signal) generated by the SIN signal excitation coil 47 and the amplitude fluctuation of the electromotive force (COS signal) generated by the COS signal excitation coil 46, the rotational position of the sensor rotor 7 is determined. Can be calculated. That is, the first detection circuit 55 removes the high frequency component of the excitation signal from the SIN signal generated by the SIN signal excitation coil 47. On the other hand, the second detection circuit 56 removes the high frequency component of the excitation signal from the COS signal generated by the COS signal excitation coil 46. Then, the computing unit 57 calculates the current angular position of the sensor rotor 7 from the amplitude ratio between the output signal of the first detection circuit 55 and the output signal of the second detection circuit 56, and uses the calculation result as angle data. Output. Therefore, in the angle sensor 1 of this embodiment, the transmission efficiency of the detection signal between the pair of rotary transformer coils 41 and 42 provided in each of the sensor stator 6 and the sensor rotor 7 is reliable as a sensor. Will be affected.

  According to the angle sensor 1 of this embodiment described above, the sensor rotor 7 is formed by integrally providing the rotor-side annular metal member 23 formed of a magnetic material on the inner peripheral side of the rotor substrate 21. A rotary transformer coil 41 is provided on the annular facing portion 23 c of the annular metal member 23. Therefore, the rotor-side annular metal member 23 that also serves as the core of the coil 41 for the rotary transformer is used for attaching the sensor rotor 7 to the rotating shaft 14. A stator-side annular metal member 35 formed of a magnetic material is integrally provided on the inner peripheral side of the stator substrate 31 to form the sensor stator 6, and a rotary transformer is formed on the annular facing portion 35 a of the annular metal member 35. Coil 42 is provided. For this reason, in order to provide the pair of coils 41 and 42 for the rotary transformer, it is not necessary to perform separate mounting work and wiring with the sensor rotor 7 and the sensor stator 6, and the productivity as the angle sensor 1 can be improved. it can.

  In this embodiment, since the annular facing portion 23c of the rotor-side annular metal member 23 of the sensor rotor 7 and the annular facing portion 35a of the stator-side annular metal member 35 of the sensor stator 6 face each other via a gap, a pair of rotary The transformer coils 41 and 42 are opposed to each other through a gap, and a magnetic flux generated between the transformer coils 41 and 42 is formed between the annular facing portions 23c and 35a. For this reason, leakage of magnetic flux can be suppressed between the coils 41 and 42 for both rotary transformers, an angle detection error as the angle sensor 1 can be reduced, and the reliability of the angle sensor 1 can be ensured. it can.

  Further, in this embodiment, for each of the sensor roller 7 and the sensor stator 6, the rotary transformer coils 41 and 42 are surrounded by the grooves 23 d and 35 b of the annular facing portions 23 c and 35 a. A magnetic closed circuit is formed by the grooves 23d and 35b with respect to the magnetic flux generated in the transformer coils 41 and 42. For this reason, the leakage of magnetic flux can be further suppressed between the pair of coils 41 and 42 for the rotary transformer, the SN ratio of the detection signal transmitted between the coils 41 and 42 can be improved, and the angle sensor 1 The noise resistance can be improved.

Second Embodiment
Next, a second embodiment in which the angle sensor according to the present invention is embodied will be described in detail with reference to the drawings.

  FIG. 7 shows a part of the angle sensor in an enlarged sectional view according to FIG. In this embodiment, it differs from 1st Embodiment by the point of arrangement | positioning of each cyclic | annular opposing part 23c, 35a. That is, in the rotor-side annular metal member 23, the annular facing portion 23 c is disposed on the outer peripheral edge portion of the metal member 23. And the groove | channel 23d which has arrange | positioned the coil 41 for rotary transformers is formed in the axial direction one side (surface 21a of the rotor board | substrate 21) side of the cyclic | annular opposing part 23c. On the other hand, in the stator side annular metal member 35, the annular facing portion 35a is disposed at a position facing the annular facing portion 23c of the rotor side annular metal member 23 described above. And the groove | channel 35b which has arrange | positioned the coil 42 for rotary transformers in the axial direction one side surface (surface 31a of the stator board | substrate 31) side of the cyclic | annular opposing part 35b is formed. In this configuration, the grooves 23d and 35b are formed in an annular shape having the same radius, and the coils 41 and 42 disposed therein are also formed in an annular shape having the same radius.

  Therefore, the same effect as the angle sensor 1 of 1st Embodiment can be acquired also about the angle sensor of this embodiment.

  The present invention is not limited to the above-described embodiments, and a part of the configuration can be changed as appropriate without departing from the spirit of the invention.

  For example, in each of the embodiments described above, the grooves 23d and 35b are formed in the annular facing portions 23c and 35a, but the grooves 23d and 35b may be omitted.

  The present invention can be used for detecting the rotation angle of a motor or an engine.

DESCRIPTION OF SYMBOLS 1 Angle sensor 2 Motor 6 Sensor stator 7 Sensor rotor 14 Rotating shaft 21 Rotor board 21a Surface 22 Planar coil 23 Rotor side annular metal member 23c Annular facing part 23d Groove 31 Stator board 31a surface 35 Stator side annular metal member 35a Annular facing part 35b Groove 41 Coil for rotary transformer (sensor rotor side)
42 Coil for rotary transformer (sensor stator side)

Claims (2)

A sensor rotor including an annular rotor substrate having a planar coil formed on a surface thereof, a rotor-side annular metal member provided on an inner peripheral side of the rotor substrate, and attached to a rotating shaft via the rotor-side annular metal member; ,
A sensor stator including a stator substrate having a surface opposed to the surface of the sensor rotor and having a planar coil formed on the surface; and a stator-side annular metal member provided on an inner peripheral side of the stator substrate. The rotor-side annular metal member and the stator-side annular metal member are each formed of a magnetic material, and the rotor-side annular metal member and the stator-side annular metal member are each formed with an annular facing portion that is opposed to each other via a gap. An angle sensor, wherein a rotary transformer coil for signal transmission is provided in each of the two annular facing portions.   2. The angle sensor according to claim 1, wherein a groove is formed in each of the two annular facing portions along a rotation direction, and each of the rotary transformer coils is disposed in each of the grooves.