JP2008292469A - Variable reluctance rotational angle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable reluctance rotational angle detector capable of improving the detection precision of a rotational angle, as compared with a conventional variable reluctance type resolver. <P>SOLUTION: The rotational angle detector comprises a rotor that is made of a magnetic material and has at least one chevron section changing periodically along a circumferential direction; and a plurality of stators for holding one portion of the outer-periphery region of the rotor from both the sides, allowing a magnetic gap to remain. The stator comprises an upper stator board and a lower stator board; a winding core for connecting them; and excitation winding and output winding wound outside the winding core, and a projection is formed on an inner surface that opposes the upper stator board and the lower stator board. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable reluctance type rotation angle detection device. In particular, an output voltage corresponding to the rotation angle of a rotating body to be detected by sandwiching a part of the outer peripheral region of a rotor having a chevron that changes periodically on the outer periphery with a plurality of stators via a magnetic gap. The present invention relates to a variable reluctance type rotation angle detection device that detects a change in the angle.

  In general, a resolver is known as a device for measuring a rotation angle of a rotating shaft of a rotating body. This resolver is an electronic device that includes a stator and a rotor, and detects the rotation angle by utilizing a phenomenon in which the mutual inductance between the stator and the rotor changes in a sine wave shape depending on the rotation position of the rotation shaft. .

  Among these types of resolvers, a variable reluctance resolver is used as a resolver that measures the rotation angle by utilizing the fact that the efficiency of the transformer changes depending on the gap provided in the magnetic path in accordance with the rotation angle of the rotating body. Are known.

JP 2001-349749 A

  In this conventional variable reluctance resolver, an excitation winding and an output winding are provided in a stator, and a rotor is rotatably incorporated inside the stator. This rotor is configured as an eccentric disk so that the gap permeance with the stator changes sinusoidally with respect to the rotation angle, or includes a plurality of chevron portions that periodically change in the outer peripheral region. Yes.

  This type of resolver has the advantage of simplifying the structure because it is not necessary to provide a winding on the rotor side.

  However, in the conventional variable reluctance type resolver, the amount of air gap in the magnetic path of the detecting portion of the opposing magnetic pole varies due to the axial deflection of the rotating shaft, so that it is easy to improve the detection accuracy of the rotation angle. There was a problem that was not. In addition, since a part of the magnetic flux passing through the magnetic path provided in the stator leaks to the outside, there is a problem that it is not easy to improve the rotation angle detection accuracy.

  Accordingly, an object of the present invention is to solve the problems of the conventional variable reluctance type resolver and to detect the rotation angle of the variable reluctance type that can improve the detection accuracy of the rotation angle as compared with the conventional variable reluctance type resolver. To provide an apparatus.

  In order to achieve the above object, a variable reluctance type rotation angle detection device according to the present invention leaves at least a rotor made of a magnetic material and having at least one chevron that periodically changes along the circumferential direction, and a magnetic gap. A plurality of stators sandwiching a part of the outer peripheral area of the rotor from both sides, and an annular stator frame that supports these stators, and the stator includes a rectangular upper stator plate and a lower stator. A plate, a winding magnetic core connecting the upper stator plate and the lower stator plate, and an excitation winding and an output winding wound around the winding magnetic core, and the upper stator Projections are formed on the inner surfaces of the plate and the lower stator plate facing each other.

  According to an embodiment of the present invention, the rotor can be configured as an eccentric disk.

According to another embodiment of the present invention, the rotor may include at least one chevron that periodically changes in a circumferential direction. In this case, the one having two chevron portions is an elliptical disk, the one having three chevron portions is a triangular disc, and the one having four chevron portions is a cross shape. It is a disk.
The stator frame is composed of an upper stator frame and a lower stator frame having the same shape and the same size, and a plurality of stators are sandwiched between the stator frames.

  According to the present invention, since the protrusions are formed on the opposing inner surfaces of the tips of the upper stator plate and the lower stator plate, the gaps in the magnetic path of the detection unit of the opposing magnetic poles are also caused by the axial deflection of the rotating shaft. Therefore, the detection accuracy of the rotating body can be improved. In addition, since leakage of magnetic flux passing through a magnetic path provided in the stator can be reduced and concentration of magnetic flux can be achieved, this also improves the detection accuracy of the rotation angle.

  Embodiments of a variable reluctance type rotation angle detection device according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of a variable reluctance type rotation angle detection device according to the present invention. FIG. 2 is a perspective view showing the lower stator frame. FIG. 3 is a perspective view showing the positional relationship between the four stators and the rotor. 4 is a longitudinal sectional view taken along line AA in FIG. FIG. 5 is a perspective view showing the lower stator plate and the excitation winding. FIG. 6 is a perspective view showing one stator, an excitation winding, and an output winding. FIG. 7 is a perspective view showing a winding magnetic core, an excitation winding, and an output winding. FIG. 8 is a longitudinal sectional view taken along line BB in FIG. FIG. 9 is a plan view showing an assembled state of the lower stator frame and the four stators.

  In FIG. 1, reference numeral 1 denotes a ring-shaped stator frame for fixing and holding a plurality of stators. The stator frame 1 is composed of an upper stator frame 2 and a lower stator frame 3. Yes. The upper stator frame 2 and the lower stator frame 3 are preferably made of a nonmagnetic material such as stainless steel or plastic material.

  The upper stator frame 2 and the lower stator frame 3 are formed in the same shape and the same size, and FIG. 2 shows the lower stator frame 3 thereof. In FIG. 2, a part of four stators 4A, 4B, 4C, and 4D, whose detailed configuration will be described later, is illustrated by phantom lines.

The lower stator frame 3 has an annular shape, and four rectangular recesses 5A, 5B, 5C, 5D are formed at equal intervals in the circumferential direction. That is, these recesses 5A, 5B, 5C, and 5D are arranged with a phase angle of 90 degrees in the circumferential direction.
Note that the configuration of the upper stator frame 2 is the same as the configuration of the lower stator frame 3, and a description thereof will be omitted.

  As is apparent from FIG. 1, a rotor 6 that can rotate around the rotation center O is disposed inside the stator frame 1. The rotor 6 is preferably configured by laminating a magnetic material or a plurality of electromagnetic steel plates. The rotor 6 has four chevron portions 7a, 7b, 7c, 7d formed at equal intervals in the circumferential direction. Since the chevron portions in this embodiment are arranged at equal intervals in the circumferential direction, the phase angle is 90 degrees. However, these chevron portions are not limited to four as shown in the figure, and any number of chevron portions can be provided as long as they change periodically in the circumferential direction.

  When there is only one chevron, it can be configured as an eccentric disk in which the center of rotation of the perfect circle is shifted by a predetermined amount. Further, when there are two chevron portions, it can be configured as an elliptical disk.

  Each of the stators 4A, 4B, 4C, and 4D has an upper stator plate 8 and a lower stator plate 10 that are arranged in parallel at a distance, as is apparent from FIGS. The planar shape is a rectangular shape. At the outer peripheral positions on the inner surfaces of the upper stator plate 8 and the lower stator plate 10, rectangular parallelepiped winding magnetic cores 11 and 12 are formed so as to protrude integrally. The upper stator plate 8 and the lower stator plate 10 are fastened and fixed to each other by a plurality of screws 14 after the winding cores 11 and 12 are abutted against each other. The upper stator plate 8 and the lower stator plate 10 can be configured by laminating a magnetic material or a plurality of electromagnetic steel plates, or can be configured by mold sintering using a steel material containing silicon. it can.

  What is important for the present invention is that the protrusions 15 and 16 are integrally formed on the opposing inner surfaces of the front end portions of the upper stator plate 8 and the lower stator plate 10, respectively. For this reason, according to the present invention, fluctuations in the amount of air gaps in the magnetic path of the detection unit of the opposing magnetic poles do not occur even when the rotation axis of the rotating shaft is shaken, so that the detection accuracy of the rotation angle can be improved. Further, since the magnetic flux passing through the magnetic path formed in the stator is easily concentrated on the projections 15 and 16, leakage of the magnetic flux can be reduced, and this also improves the accuracy of detecting the rotation angle. Can do. Furthermore, since the magnetic flux passing through the magnetic path is easily concentrated on the protrusions 15 and 16, the output voltage can be increased.

  As is apparent from FIG. 7, an excitation winding 17 and an output winding 18 are wound around the winding magnetic core 11 and the winding magnetic core 12 so as to overlap in the axial direction. A single-phase AC voltage is applied to the excitation winding 17, while a one-phase output voltage is detected from the output winding 18.

  The protrusions 15 and 16 of the upper stator plate 8 and the lower stator plate 10 constituting the stator may be formed by double-folding the tip portions of the plates and locally doubling the thickness. Alternatively, a dowel may be formed near the tip of the stator plate, and a separately prepared magnetic pole piece made of the same material may be caulked and fixed.

  Since the present invention is configured as described above, fluctuations in the amount of air gaps in the magnetic path of the detection unit of the opposing magnetic pole do not occur even when the rotation axis of the rotating shaft is shaken, thereby improving the detection accuracy of the rotating body. be able to. In addition, since leakage of magnetic flux passing through a magnetic path provided in the stator can be reduced and concentration of magnetic flux can be achieved, this also improves the detection accuracy of the rotation angle.

  In the above embodiment, for example, the output signal extracted from the output windings of the stators 4A and 4C and the output signal extracted from the output windings of the stators 4B and 4D have been described as being in phase. The variable reluctance type rotation angle detection device is not limited to this. The variable reluctance type rotation angle detection device in the first modification of the above-described embodiment according to the present invention includes, for example, the phase (for example, SIN phase) of the output signal extracted from the output windings of the stators 4A and 4C and the stator 4B, Output signals having different phases (for example, COS phase) of output signals taken out from the 4D output winding can be output, and the detection accuracy of the rotation angle can be further improved by signal processing on these output signals. .

  FIG. 10 is a perspective view showing a variable reluctance type rotation angle detection device in a first modification of the present embodiment. 10, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The rotation angle detection device in the first modification is different from the rotation angle detection device in the above embodiment in the rotor. That is, in the rotation angle detection device in the above embodiment, the rotor 6 has the four chevron portions 7a, 7b, 7c, 7d formed at equal intervals in the circumferential direction. In the rotation angle detection device in the example, the rotor 106 is a perfect circle in a plan view, and the rotation axis is provided to be rotatable around a rotation center O ′ at a position shifted from the rotation center O (see FIG. 10). The rotor 106 is also preferably configured by laminating a magnetic material or a plurality of electromagnetic steel plates, like the rotor 6.

  In the rotation angle detection device according to the first modified example having such a configuration, when the area where the stator 4A overlaps the rotor 106 increases in plan view, the area where the stator 4C paired with the stator 4A overlaps the rotor 106 decreases. Become. Similarly, when the area where the stator 4 </ b> A overlaps the rotor 106 decreases in plan view, the area where the stator 4 </ b> C overlaps the rotor 106 increases.

  Furthermore, in plan view, when the area where the stator 4B overlaps the rotor 106 increases, the area where the stator 4D paired with the stator 4B overlaps the rotor 106 decreases. Similarly, in plan view, when the area where the stator 4B overlaps the rotor 106 decreases, the area where the stator 4D overlaps the rotor 106 increases.

  Accordingly, the rotation of the rotor 106 around the rotation center O ′ causes the voltage between the output windings of the stators 4A and 4C and the voltage between the output windings of the stators 4B and 4D to increase, and output for each phase. By performing signal processing such as differential amplification of signals, an output signal corresponding to the rotation angle of the rotor 106 can be detected with high accuracy.

  Further, also in the first modified example, similar to the above-described embodiment, the protrusions 15 and 16 are integrally formed on the opposing inner surfaces of the front end portions of the upper stator plate 8 and the lower stator plate 10, respectively. Is formed. For this reason, according to the first modification, the amount of the air gap in the magnetic path of the detection unit of the opposing magnetic pole does not change even when the shaft swings, so that the detection accuracy of the rotation angle is improved. Can do. Further, since the magnetic flux passing through the magnetic path formed in the stator is easily concentrated on the projections 15 and 16, leakage of the magnetic flux can be reduced, and this also improves the accuracy of detecting the rotation angle. Can do. Furthermore, since the magnetic flux passing through the magnetic path is easily concentrated on the protrusions 15 and 16, the output voltage can be increased.

  In the above-described embodiment and the first modification, the example in which the four stators 4A, 4B, 4C, and 4D are arranged at equal intervals in the circumferential direction has been described. However, the present invention is limited to this. It is not a thing. The variable reluctance type rotation angle detection device in the second modification of the above embodiment according to the present invention includes, for example, the phase of the output signal (for example, SIN phase) taken from the output windings of the stators 4A and 4C and the stator 4B, Output signals having different phases (for example, COS phase) of output signals taken out from the 4D output winding can be output, and the detection accuracy of the rotation angle can be further improved by signal processing on these output signals. .

  FIG. 11 is a perspective view showing a variable reluctance type rotation angle detection device in a second modification of the present embodiment. FIG. 12 is a perspective view showing a lower stator frame in the second modified example. FIG. 13 is a perspective view showing the positional relationship between the four stators and the rotor in the second modification. FIG. 14 is a plan view showing an assembled state of the lower stator frame and the four stators in the second modification. FIG. 15 is an explanatory diagram showing the relationship between the rotation angle of the rotor 6 and the output signal in the second modification. 11 to 14, the same parts as those in FIGS. 1 to 3 and 9 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  The difference between the rotation angle detection device in the second modification and the rotation angle detection device in the above embodiment is the positional relationship between the four stators 4A, 4B, 4C, 4D. That is, in the rotation angle detecting device in the above embodiment, the four stators 4A, 4B, 4C, 4D are arranged at equal intervals with an arrangement angle of 90 degrees in the circumferential direction (see FIG. 1). On the other hand, in the rotation angle detection device according to the second modification, the stators 4C and 4D are arranged in the circumferential direction (clockwise) at an arrangement angle of θ (0 <θ <90) degrees, and the stators 4D and 4A are arranged in the circumferential direction ( The arrangement angle of θ degrees is arranged clockwise (clockwise), and the stators 4A and 4B are arranged at an arrangement angle of θ degrees circumferentially (clockwise) (see FIG. 11).

  More specifically, the rotation angle detection device according to the second modification has a ring-shaped stator frame 201 for fixing and holding a plurality of stators, and the stator frame 201 is an upper stator frame. 202 and a lower stator frame 203. As shown in FIG. 12, the lower stator frame 203 has an annular shape, and four rectangular recesses 205C and 205D are disposed at the inner side thereof by θ degrees in the circumferential direction (clockwise). The recesses 205D and 205A are formed with an arrangement angle of θ degrees in the circumferential direction (clockwise), and the recesses 205A and 205B are formed with an arrangement angle of θ degrees in the circumferential direction (clockwise). . The upper stator frame 202 and the lower stator frame 203 are formed in the same shape and the same size, and the configuration of the upper stator frame 202 is the same as the configuration of the lower stator frame 203, and thus the description thereof is omitted.

  Inside the stator frame 201, as shown in FIG. 11, a rotor 6 that is rotatable about a rotation center O is disposed. The rotor 6 has four chevron portions 7a, 7b, 7c, 7d formed at equal intervals in the circumferential direction. Since the chevron portions in this embodiment are arranged at equal intervals in the circumferential direction, the phase angle is 90 degrees.

  However, these chevron portions are not limited to four as shown in the figure, and any number of chevron portions can be provided as long as they change periodically in the circumferential direction. In this case, the stator is arranged at an arrangement angle corresponding to the number of angle portions.

  In the rotation angle detection device in the second modified example having such a configuration, when the area where the stator 4A overlaps the chevron of the rotor 6 is the maximum in plan view, the stator 4C paired with the stator 4A is the rotor 6 The stators 4A, 4B, 4C, and 4D are arranged in accordance with the contour shape of the rotor 6 so that the area overlapping the chevron is minimized. Similarly, in plan view, when the area where the stator 4A overlaps the chevron of the rotor 6 is the smallest, the area where the stator 4C overlaps the chevron of the rotor 6 is maximized according to the contour shape of the rotor 6. Stator 4A, 4B, 4C, 4D is arrange | positioned.

  Further, in plan view, when the area where the stator 4B overlaps the chevron portion of the rotor 6 is maximum, the area of the rotor 6 so that the area where the stator 4D paired with the stator 4B overlaps the chevron portion of the rotor 6 is minimized. Stator 4A, 4B, 4C, 4D is arrange | positioned according to an outline shape. Similarly, in plan view, when the area where the stator 4B overlaps the chevron of the rotor 6 is the smallest, the area where the stator 4D overlaps the chevron of the rotor 6 is maximized according to the contour shape of the rotor 6. Stator 4A, 4B, 4C, 4D is arrange | positioned.

  Therefore, the rotation of the rotor 6 maximizes the voltage between the output windings of the stators 4A and 4C and the voltage between the output windings of the stators 4B and 4D. As shown in FIG. By performing signal processing such as differential amplification, an output signal corresponding to the rotation angle of the rotor 6 can be accurately detected.

  Further, also in the second modified example, similar to the above-described embodiment, the protruding portions 15 and 16 are integrally formed on the mutually opposing inner surfaces of the tip portions of the upper stator plate 8 and the lower stator plate 10, respectively. Is formed. For this reason, according to the second modification, since the amount of the air gap in the magnetic path of the detecting portion of the opposite magnetic pole does not change even if the shaft swings, the rotation angle detection accuracy can be improved. Can do. Further, since the magnetic flux passing through the magnetic path formed in the stator is easily concentrated on the projections 15 and 16, leakage of the magnetic flux can be reduced, and this also improves the accuracy of detecting the rotation angle. Can do. Furthermore, since the magnetic flux passing through the magnetic path is easily concentrated on the protrusions 15 and 16, the output voltage can be increased.

  As described above, the variable reluctance type rotation angle detection device of the present invention has been described based on the above-described embodiment and the first or second modification. However, the present invention is not limited to this, and the gist thereof is as follows. The present invention can be implemented without departing from the scope, and for example, the following modifications are possible.

(1) In the above embodiment and the first or second modification, the present invention has been described by taking the case where the planar shape of the upper stator plate and the lower stator plate is rectangular as an example. It is not limited to. For example, the planar shape of the upper stator plate and the lower stator plate may be a fan shape or other shapes.

The perspective view which showed one Embodiment of the variable reluctance type rotation angle detection apparatus by this invention. The perspective view which showed the lower side stator frame. The perspective view which showed the arrangement | positioning relationship between four stators and a rotor. FIG. 2 is a longitudinal sectional view taken along line AA in FIG. 1. The perspective view which showed the lower stator board and the excitation winding. The perspective view which showed one stator, the exciting winding, and the output winding. The perspective view which showed the coil | winding magnetic core, the excitation coil | winding, and the output coil | winding. The longitudinal cross-sectional view cut | disconnected and shown along the BB line of FIG. The top view which showed the assembly state of a lower side stator frame and four stators. The perspective view which showed the variable reluctance type rotation angle detection apparatus in the 1st modification of this embodiment. The perspective view which showed the variable reluctance type rotation angle detection apparatus in the 2nd modification of this embodiment. The perspective view which showed the lower side stator frame in the 2nd modification. The perspective view which showed the arrangement | positioning relationship between four stators and a rotor in a 2nd modification. The top view which showed the assembly state of the lower side stator frame and four stators in a 2nd modification. Explanatory drawing which showed the relationship between the rotation angle of the rotor in a 2nd modification, and an output signal.

Explanation of symbols

1, 201 ... Stator frame, 2, 202 ... Upper stator frame, 3, 203 ... Lower stator frame,
4A, 4B, 4C, 4D ... stator,
5A, 5B, 5C, 5D, 205A, 205B, 205C, 205D ... recess,
6, 106 ... rotor, 7a, 7b, 7c, 7d ... chevron, 8 ... upper stator plate,
10 ... Lower stator plate 11, 12 ... Winding core, 15, 16 ... Projection,
17 ... Excitation winding, 18 ... Output winding

Claims (6)

A rotor made of a magnetic material and having at least one chevron that periodically changes along the circumferential direction, a plurality of stators sandwiching a part of the outer peripheral region of the rotor from both sides, leaving a magnetic gap, and It consists of an annular stator frame that holds and holds the stator of
The stator includes an upper stator plate and a lower stator plate, a winding magnetic core connecting the upper stator plate and the lower stator plate, and an excitation winding wound around the outer side of the winding magnetic core. And a variable reluctance type rotation angle detecting device, characterized in that a protrusion is formed on the inner surface of the upper stator plate and the lower stator plate facing each other.   The variable reluctance type rotation angle detection device according to claim 1, wherein the rotor is an eccentric disk.   The variable reluctance type rotation angle detecting device according to claim 1, wherein the rotor is an elliptical disk.   The variable reluctance type rotation angle detection device according to claim 1, wherein the rotor is a substantially triangular disk.   The variable reluctance type rotation angle detecting device according to claim 1, wherein the rotor is a substantially cross-shaped disk.   2. The stator frame according to claim 1, wherein the stator frame includes an upper stator frame and a lower stator frame, and a plurality of stators are sandwiched between the upper stator frame and the lower stator frame. The variable reluctance type rotation angle detection device described in 1.