JP2007114074A - Variable reluctance type resolver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable reluctance type resolver, having axial double angle of 2X which can detect actual rotation angle starting from a specified rotation angle standard point as the start point, and moreover, which is simple in structure. <P>SOLUTION: The variable reluctance type resolver with an axial double angle of 2X changes the value of the gap permeance between a coil on a stator and a rotor, in accordance with a sinusoidal function according to the rotation angle of the rotor. The perimeters 201, 202 of the rotor are defined by standard radii 101, 102. When a clockwise angle ϕ lies within the range of 270 to 90 degrees, with a rotor rotating shaft 103 as the center, the value of the standard radius 101 is set to R<SB>01</SB>. When the angle ϕ lies within the range of 90 to 270 degrees, the value of the standard radius 102 is set to R<SB>02</SB>, which is smaller than R<SB>01</SB>. Detection voltages of coils, which are located at axially symmetric positions with respect to the rotor rotating shaft 103, are output. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable reluctance resolver used as a rotation angle detection sensor in a rotary motor, a generator or the like, and in particular, the actual rotation angle can be specified with one rotation angle reference point as a starting point, excluding indefinite detection angle. The present invention relates to a variable reluctance resolver having a shaft angle multiplier of 2X.

  In general, a variable reluctance resolver is used as a rotational angle detection sensor for rotational speed control or commutation control in various rotary motors or generators. FIG. 9 (a) is a perspective view conceptually showing the appearance of an example of a variable reluctance resolver that has been conventionally used. FIG. 9B is a front view of the resolver viewed from a direction parallel to the rotation axis. The resolver in FIG. 9 has a stator 1 and a rotor 2, and the stator 1 is provided with excitation and detection coils 3. As is apparent with reference to FIG. 9, the rotor 2 does not include a coil and is formed only of a magnetic material such as a silicon steel plate. The stator 1 is provided with eight excitation / detection coils 3.

  The outer peripheral shape of the rotor 2 is formed such that the gap permeance between the coil 3 and the outer periphery of the rotor 2 is a sine wave function of the rotation angle of the rotor 2. In accordance with the rotation of the rotor 2, a sinusoidal voltage for detecting the rotation angle of the rotor 2 is output from the coil 3. Since the resolver is a kind of rotation angle detection sensor, it is preferable to improve the rotation angle detection accuracy of the resolver. Therefore, a resolver that obtains a sinusoidal voltage output corresponding to n cycles corresponding to one rotation of the rotor 2 is called an nX resolver and is in practical use. Here, n is a shaft angle multiplier.

  The nX resolver outputs a sinusoidal voltage for n cycles corresponding to one rotation of the rotor 2. This nX resolver cannot detect an actual rotation angle starting from a specific rotation angle reference point if the principle structure is not modified. For example, if X is 2, it can be detected from the output of the 2X resolver that the rotation angle of the rotor 2 is either θ or θ + 180 degrees starting from the rotation angle reference point. Cannot be specified. That is, if the rotation angle of the rotor is detected with a simple 2X resolver output, 180 degrees of indefiniteness remains in the detection of the rotation angle of the rotor. In order to use the 2X resolver as a complete rotation angle detection sensor, it is necessary to remove the ambiguity of the detection angle and specify the actual rotation angle of the rotor starting from one rotation angle reference point.

  Various means have been proposed in the past to eliminate the indefiniteness of the detection angle. For example, Patent Document 1 (Japanese Patent Laid-Open No. 05-010779) discloses an improvement proposal for a magnetic resolver configured by combining a 1X resolver with an nX resolver. In this proposal, the rotor cores of the 1X resolver and the nX resolver are arranged on the same plane of the rotor plate, and the salient poles provided on both of these resolvers are also arranged on the same plane of the stator plate. The 1X resolver and the nX resolver both have a function of detecting the rotational angle position based on the change in the facing area between the rotor core and the salient pole. Is less affected by error factors such as temperature change and moment load compared to an eccentric type magnetic resolver that detects the rotational angle position based on a minute gap change between the rotor and stator. It is assumed that a magnetic resolver can be realized.

As another example, Patent Document 2 (Japanese Patent Laid-Open No. 2000-258187) describes a proposal for improving a zero position detection device used in a conventional variable reluctance resolver. In this proposal, in addition to the excitation and detection coils, a zero-position detection coil is newly provided in the stator, and the rotor is provided with a detection unit consisting of a concave portion or a convex portion. This position can be detected by a voltage change output from the zero position detection coil.
JP 05-010779 JP 2000-258187 A

  Each of the conventional variable reluctance resolvers described above has problems to be solved. The magnetic resolver disclosed in Patent Document 1 is configured by combining two sets of resolvers each including a 1X resolver and an nX resolver formed on a flat plate in a mutually opposing form for the purpose of flattening. Therefore, the structure becomes complicated and the size increases.

The variable reluctance resolver zero position detection device described in Patent Document 2 requires a special structure for detecting the zero position in addition to the original function of the variable reluctance resolver. The structure becomes complicated.
An object of the present invention is to provide a variable reluctance type resolver having a shaft double angle of 2X and capable of detecting an actual rotation angle starting from a specific rotation angle reference point and having a simple structure.

  In order to solve the above-mentioned problems, the present invention provides the following means.

(1) A rotor including only a magnetic material without including a coil, and a stator including a plurality of excitation coils and a plurality of detection coils. The detection coil and an outer peripheral portion of the rotor In the variable reluctance type resolver having a shaft double angle of 2X in which the outer peripheral shape of the rotor is formed such that the gap permeance changes in a sinusoidal manner with respect to the rotation angle of the rotor,
Assuming that the angle at which the outer periphery of the rotor is viewed from the rotation axis of the rotor is φ, the reference radius defining the outer peripheral shape of the rotor is mutually in the range where φ ranges from 0 ° to 180 ° and from 180 ° to 360 °. Variable reluctance type resolver characterized by being different.

(2) The voltage output terminal for specifying the rotation angle of the rotor is provided in the two detection coils that are axially symmetric with respect to the rotation axis. Variable reluctance type resolver.

 In the above-described configuration of the present invention, the rotor is divided into two equal parts by the 180 degree angle sections that allow the rotor outer periphery to be seen from the rotor rotation shaft, and the outer peripheral shape of the rotor is different from the two reference radii corresponding to each angle section It is prescribed by. Therefore, a difference is generated in the output voltage from the pair of detection coils arranged at symmetrical positions with respect to the rotor rotation axis, and the polarity of the voltage difference is reversed to either positive or negative each time the rotor rotates 180 degrees. In a variable reluctance type resolver having a shaft double angle of 2X employing this configuration, the polarity of the voltage difference is discriminated to remove the 180 degree indefiniteness in detecting the rotation angle of the rotor, and the rotor starting from the rotation angle reference point The rotation angle is specified. As described above, according to the present invention, the rotational angle of the rotor can be determined only by a simple configuration in which the outer peripheral shape of the rotor is defined by two different reference radii, except for indefiniteness of 180 degrees in detecting the rotational angle of the rotor. It is possible to provide a variable reluctance type resolver having a shaft double angle of 2X that enables identification.

Next, embodiments of the present invention will be described with reference to the drawings. The present embodiment is a variable reluctance type resolver having a shaft angle multiplier of 2X, and is formed of a stator in which a plurality of coils for excitation and detection are arranged, and a magnetic material such as iron or silicon steel plate that does not have a coil. It is composed of a rotor. FIG. 1 is a diagram schematically showing how to define the outer peripheral shape of the rotor corresponding to a predetermined reference radius in the present embodiment. In the figure, reference numeral 103 denotes a rotating shaft of the rotor, and 201 and 202 denote the outer periphery of the rotor. 101 and 102 are reference radii that define the outer peripheries 201 and 202 of the rotor, respectively. R ₀₁ and R ₀₂ are values of the reference radii 101 and 102 (length, R ₀₁ > R ₀₂ ), respectively. φ is an angle in polar coordinates that changes clockwise about the rotor rotation axis 103. δ ₀ is a gap between the reference radius and the rotor when φ is 45 degrees and 135 degrees and 225 degrees and 315 degrees. δ ₁ is a gap between the reference radius and the rotor when φ is 0 degree and 180 degrees. R ₁ is the radius of the rotor when φ is between 270 and 90 degrees. R ₂ is the radius of the rotor when φ is between 90 degrees and 270 degrees.

In the angle range of φ from 270 degrees to 90 degrees, the shape of the outer periphery 201 of the rotor is defined by the reference radius 101. Further, in the angle range of φ from 90 degrees to 270 degrees, the shape of the outer periphery 202 of the rotor is defined by the reference radius 102. By defining the radii R ₁ and R ₂ of the rotor as described below, the permeance (gap permeance) in the gap between the outer periphery 201 and 202 of the rotor and each coil of the stator is sine according to the rotation angle of the rotor. It changes in a wave shape.

The rotor radii R ₁ and R ₂ are given by equations (1) and (2), respectively.
R ₁ = R ₀₁ −δ ₀ / {1+ (δ ₀ / δ ₁ −1) cos 2φ} (1)
R ₂ = R ₀₂ −δ ₀ / {1+ (δ ₀ / δ ₁ −1) cos2φ} (2)
R ₁ : Diameter from the rotor rotation shaft 103 to the rotor outer periphery 201 at φ = 270 ° to 90 °
R ₂ : Diameter from the rotor rotation shaft 103 to the rotor outer periphery 202 at φ = 90 ° to 270 °
R ₀₁ : Value of the reference radius 101 (length)
R ₀₂ : Value of the reference radius 102 (length)
δ ₀ : Gap between rotor outer circumference 201 and reference radius 101 at φ = 45 °, 135 °, 225 °, 315 °
δ ₁ : Gap between rotor outer periphery 202 and reference radius 102 at φ = 0 ° and 180 °
Note that δ ₀ > δ ₁ .

FIG. 2 shows a state of the stator in the embodiment (variable reluctance resolver having a shaft angle multiplier of 2X) including the rotor 2 having the outer peripheral shape defined by the equations (1) and (2) described above with reference to FIG. FIG. 3 is a conceptual diagram showing a positional relationship between a coil and a rotor 2. It is assumed that the number of coils on the stator is 2n (n: a positive integer), and the number of coils is generalized for explanation. Coil _{T 1, T 2, T 3} , ···· T n-1, T n, T n + 1, T n + 2, are indicated by · · · · T _2n becomes symbols. As a symbol of the dynamic rotation angle of the rotor 2, θ is used. Each coil constitutes a SIN output coil or a COS output coil, and the SIN output is a signal output by connecting T ₁ , T ₃ ,... T _2n−1 coils in series. , COS output is a signal output by connecting T ₂ , T ₄ ,..., T _2n coils in series.

In the present embodiment, as shown in FIG. 2, the coil _{T 1, T 2, T 3} , ···· T n-1, T n, T n + 1, T n + 2, head · · · · T _2n All the parts are arranged on the stator 1 at equal intervals at a position in contact with the reference radius 101. FIG. 2 shows a state in which the rotor 2 is rotated 90 degrees in the clockwise direction from the starting point at a rotation angle of 0 degrees. When the rotation angle θ is between 0 ° and 180 °, the gap G ₁ between the coil T ₁ and the rotor 2 is expressed by the following equation (3).
G ₁ = R ₀₁ −R ₁
= Δ ₀ / {1+ (δ ₀ / δ ₁ −1) cos 2θ} (3)
G ₁ : Gap between coil T ₁ and rotor 2

The gap G _{n + 1} between the rotor T 2 and the coil T _{n + 1} located at an angle symmetrical to the coil T ₁ with respect to the rotor rotation shaft 103 is the following (4) when the rotation angle θ is in the range of 0 ° to 180 °. It is expressed by a formula.
G _{n + 1} = R ₀₁ -R ₂
= R ₀₁ -R ₀₂ + δ ₀ / {1+ (δ ₀ / δ ₁ -1) cos 2θ}
.... (4)
G _{n + 1} : Gap between coil T _{n + 1} and rotor 2

As apparent from the above equations (3) and (4), when the rotation angle θ is between 0 degrees and 180 degrees, G ₁ <G _{n + 1} and the value of the gap permeance in the coil T _{n + 1} Takes a value smaller than the value of the gap permeance in the coil T ₁ . On the other hand, when the rotation angle θ is 180 ° to 360 °, G ₁ > G _{n + 1} is satisfied.

Assuming that the voltage output from the coil T ₁ is V ₁ and the voltage output from the coil T _{n + 1} is V _{n + 1} , V ₁ > V _{n + 1} when the rotation angle θ is between 0 ° and 180 °. When V ₁ −V _{n + 1} is ΔV, ΔV> 0, and the polarity of the voltage difference ΔV is positive. When the rotation angle θ is between 180 degrees and 360 degrees, the magnitude relationship of the gap permeance value is reversed, V ₁ <V _{n + 1} , and the polarity of the voltage difference ΔV is negative. This phenomenon is not limited only to the relationship between the coil T ₁ and the coil T _{n + 1,} and the same applies to all other pairs of coils that are in symmetrical positions with respect to the rotating shaft 103 and make a pair. For example, the same is true between the coil T ₂ and the coil T _{n + 2} or between the coil T _n and the coil T _2n . That is, paying attention to a pair of coils that are symmetrical to each other with respect to the rotating shaft 103, and by taking the difference ΔV of the induced voltage detected by the pair of coils and determining the polarity of ΔV, the rotor 2 It is possible to determine whether the rotation position is a rotation position corresponding to the first period or a rotation position corresponding to the second period. Therefore, indefiniteness in detecting the rotation angle in the 2X resolver is removed, and the rotation angle θ of the rotor 2 can be detected deterministically.

Next, an embodiment of the present invention will be described with reference to FIGS. 1, 3, 4, 5, 6, 7 and 8. In this embodiment, for the reference radius and gap in FIG. 1, the value R ₀₁ of the reference radius 101 is 15.000 mm, the value R ₀₂ of the reference radius 102 is 14.090 mm, the gap δ ₀ is 2 mm, and the gap δ ₁ is 1 mm. Is done.

FIG. 3 is a conceptual diagram showing the positional relationship between the stator 1 and the rotor 2 of the present embodiment, and the eight coils T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T shown by broken lines. ₆ , T _7, and T ₈ are all arranged at equal intervals on the stator 1 at a position in contact with the reference radius 101. FIG. 4 is a conceptual diagram showing a specific structure of FIG. By setting the reference radius 101, the reference radius 102, and the values of the gaps δ ₀ and δ ₁ with such an arrangement, the coils T ₁ , T ₂ , T ₃ and T ₄ are shown in FIG. Sinusoidal voltages V ₁ , V ₂ , V _3, and V ₄ are generated, respectively, and from the coils T ₅ , T ₆ , T _7, and T ₈ , sinusoidal voltages V ₅ , V ₆ , V ₇ and V ₈ are generated, respectively.

As is apparent with reference to FIGS. 5 and 6, the output voltage of each coil becomes an output voltage of two cycles when the rotation angle θ of the rotor 2 is in the range of 0 degrees to 360 degrees. When the rotation angle θ is between 0 ° and 180 ° and between 180 ° and 360 °, the output voltage is also different because the radius of the rotor ₂ is different between R ₁ and R ₂ . In FIG. 5, for example, in the case of the coil T ₁ , the output voltage V ₁ is 1.5 V in the state of 90 degrees and (1.5−δV) V in the state of 270 degrees. In FIG. 6, in the case of the coil T ₅ , the output voltage V ₅ is (1.5−δV) in the 90 degree state and 1.5 V in the 270 degree state.

Therefore, if the voltage difference ΔV between the voltage V ₁ output from the coil T ₁ and the voltage V ₅ output from the coil T ₅ is examined, the rotation angle θ is between 0 ° and 180 °, and ΔV > 0, polarity is positive, rotation angle θ is between 180 degrees and 360 degrees, ΔV <0, polarity is negative.

Figure 7 is a voltages V ₁ output from the coil T _1, the change in the value of the voltage difference △ V between the voltage V ₅ output from the coil T _5, over 0 to 360 ° range of the rotation angle θ Show. Note display numbers on the vertical axis in FIG. 7, for example, in the case of [2.5E-02], [2.5 × 10 -2] Represents.

  FIG. 8 shows the angle detection error of the present embodiment when the rotation angle θ is in the range of 0 degrees to 360 degrees. The angle detection error caused by changing the reference radius value for the rotor 2 in the first and second periods is an extremely small value within ± 0.0002 degrees, and is an angle required for a variable reluctance resolver. It is sufficiently small compared with the error (from 0.2 degrees to 1 degree). Thus, practically sufficient angular accuracy can be obtained.

  In the above-described embodiment of the present invention, the variable reluctance with a shaft double angle of 2X is obtained by referring to the difference ΔV between the output voltages of the coils at axially symmetrical positions with respect to the rotor rotation shaft 103 and determining the polarity of the ΔV. Indefiniteness in detecting the rotation angle in the mold resolver is removed, and the rotation angle θ of the rotor 2 can be uniquely specified. As shown in this embodiment, the variable reluctance type resolver having a shaft angle multiplier of 2X according to the present invention is characterized by a rotor with a specially designed outer peripheral shape without any particular elements added thereto, and its structure is very simple. Therefore, the variable reluctance type resolver having a shaft multiplication angle of 2X according to the present invention is different from the structures described in Patent Documents 1 and 2 that allow the rotational angle θ to be uniquely specified by adding a special element. Can be manufactured.

In embodiment of this invention, it is the figure which showed typically the method of prescribing | regulating the outer periphery shape of a rotor. It is the conceptual diagram which showed the arrangement | positioning relationship between the coil on the stator and rotor in embodiment of FIG. It is the conceptual diagram which showed the arrangement | positioning relationship between the coil on the stator and rotor in the Example of this invention. It is the conceptual diagram which showed the specific structure of the Example of FIG. ₄ is a chart showing a relationship between a rotation angle of a rotor and voltages output from coils T ₁ , T ₂ , T ₃ , and T ₄ in the embodiment of FIG. 4 is a chart showing a relationship between a rotation angle of a rotor and voltages output from coils T ₅ , T ₆ , T ₇ , T ₈ in the embodiment of FIG. FIG. 4 is a chart showing the relationship between the output voltage difference ΔV from the coils located symmetrically with respect to the rotation axis and the rotation angle of the rotor in the embodiment of FIG. 3. 4 is a chart showing the relationship between the rotation angle of the rotor and the angle detection error in the embodiment of FIG. It is the conceptual diagram which showed the specific structure of the variable reluctance type resolver of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 2 Rotor 3 Coil 103 Rotor's rotating shaft 101, 102 Reference radius 201 and 202 which define rotor outer periphery 201 and 202, respectively Rotor outer periphery _R01 , _R02 Reference radius 101 and 102 value (length, _R01) > _R02 )
φ To define the rotor shape, the angle in polar coordinates that moves clockwise around the rotor rotation axis 103 θ The rotation angle of the rotor δ _{0 When} φ is 45 degrees, 135 degrees, 225 degrees, and 315 degrees Gap between the reference radius of the rotor and the rotor δ ₁ φ is 0 degrees and 180 degrees, and the gap between the reference radius and the rotor R ₁ φ is between 0 degrees and 180 degrees, and the rotor radius R ₂ φ is Radius of rotor when it is between 180 degrees and 360 degrees T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , T ₇ , T ₈ coil ΔV Coil at positions symmetrical to each other with respect to rotating shaft 103 Difference of output voltages V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , V ₆ , V ₇ , V ₈ coils T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , T ₇ , T ₈ output voltage

Claims (2)

A gap between the detection coil and the outer periphery of the rotor, the rotor including only a magnetic material without a coil, and a stator including a plurality of excitation coils and a plurality of detection coils. In a variable reluctance type resolver having a shaft angle multiplier of 2X in which the outer peripheral shape of the rotor is formed such that the permeance changes sinusoidally with respect to the rotation angle of the rotor,
Assuming that the angle at which the outer periphery of the rotor is viewed from the rotation axis of the rotor is φ, the reference radius defining the outer peripheral shape of the rotor is mutually in the range where φ ranges from 0 ° to 180 ° and from 180 ° to 360 °. Variable reluctance type resolver characterized by being different.   2. The variable reluctance resolver according to claim 1, wherein a voltage output terminal for specifying a rotation angle of the rotor is provided in the two detection coils that are axially symmetric with respect to the rotation axis. .

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