JPH0510779A - Magnetic resolver - Google Patents

Abstract

PURPOSE:To provide a magnetic resolver which can be flattened even when an 1X resolver and an nX resolver are combined together and which is scarcely affected by error factors such as temperature changes and moment loads. CONSTITUTION:An 1X resolver and an nX resolver have their respective rotor cores 12, 13 disposed on the same plane of a rotor plate 11 and also have their respective stator cores disposed on the same plane of a stator plate 21 so as to flatten the resolvers. The 1X resolver and the nX resolver are so designed to detect rotary positions according to changes in the opposite areas between the rotor cores 12, 13 and salient poles, so that the resolver are scarcely affected by error factors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a magnetic resolver which detects absolute rotational position by combining a 1X resolver and an nX resolver.

[0002]

2. Description of the Related Art As a magnetic resolver capable of detecting an absolute rotational position, the phase of the detection signal is 3 when the rotor makes one rotation.
There is a combination of a 1X resolver modulated by 60 ° and an nX resolver in which the phase of the detection signal is modulated by 360 ° every 1 / n rotation (n is an integer) of the rotor. In this magnetic resolver, the rotation position is detected with the resolution of 1 / n rotation by the detection signal of the 1X resolver, and the rotation position within the detected 1 / n rotation is detected by the detection signal of the nX resolver to detect the absolute rotation position. To do. In such a magnetic resolver, since the 1X resolver and the nX resolver are superposed, the resolver becomes thick.

As a flattened magnetic resolver,
For example, there was an eccentric type magnetic resolver described in the specification of Japanese Patent Application No. 63-205971 by the present applicant.
This magnetic resolver makes the center of rotation of the rotor eccentric with respect to the center of the stator, and makes one rotation of the rotor
The absolute rotational position is detected by one rotor by utilizing the fact that the gap between the stators changes by one cycle.
However, in the eccentric type magnetic resolver, position detection is performed based on the minute gap between the rotor and the stator, so error factors such as temperature change and moment load applied to the magnetic resolver There was a problem that it was weak.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to realize a magnetic resolver that simultaneously solves the drawbacks of a magnetic resolver in which a 1X resolver and an nX resolver are combined and an eccentric type magnetic resolver. That is, it is an object of the present invention to realize a magnetic resolver that can realize flattening even if a 1X resolver and an nX resolver are combined and that is not easily affected by error factors such as temperature change and moment load.

[0005]

According to the present invention, a 1X resolver in which the phase of a detection signal is modulated by 360 ° each time the rotor makes one rotation, and the rotor makes 1 / n rotation (n is an integer). An nX resolver in which the phase of the detection signal is modulated by 360 ° is provided for each, and the rotation position is detected with the resolution of 1 / n rotation by the detection signal of the 1X resolver, and the rotation position within the detected 1 / n rotation is detected. In a magnetic resolver that detects an absolute rotational position by detecting with a detection signal of the nX resolver, a rotor plate having a disc shape and a ring shape having a ring width of n + 1 steps for one round of the ring. And the first rotor core attached to the rotor plate, and the ring shape changes the ring width by n cycles for one round of the ring and is attached to the rotor plate. Be A second rotor core, a disc-shaped stator plate, and a stator plate mounted on the stator plate at a position facing the first rotor core,
A first salient pole, the area of the portion of which overlaps with the first rotor core changes according to the rotational position of the rotor, and a position on the stator plate that faces the second rotor core. A second salient pole attached to the first rotor, the area of a portion of which overlaps with the second rotor core changes according to the rotational position of the rotor;
First and second coils respectively wound on the first and second salient poles, exciting means for exciting the first and second coils, and an induced voltage of the first coil is detected to detect the detected voltage. Based on the above, the fact that the inductance of the first coil changes according to the area of the portion where the first salient pole and the first rotor core overlap makes it possible to use one of n + 1 signal levels. A first detection circuit that outputs a detection signal having one level and an induced voltage of the second coil are detected, and based on this detection voltage, the inductance of the second coil is the second salient pole. A second detection circuit that outputs a detection signal of a rotation position within 1 / n rotation by utilizing the fact that the second rotation core and the second rotor core change according to the area of the overlapping portion, and the first detection circuit. Based on the output level of, the detection position by the second detection circuit is The number of cycles in rotation that is 1 / n rotation is detected, and based on the detected cycle number and the rotation position within 1 / n rotation detected by the second detection circuit, the rotor A magnetic resolver, comprising: a calculation unit for obtaining absolute rotation.

[0006]

According to the present invention, the rotor cores of the 1X resolver and the nX resolver are arranged on the same plane of the rotor plate, and the stator cores of the 1X resolver and the nX resolver are also arranged on the same plane of the stator plate. Flattening is achieved by placing it above. Further, the 1X resolver and the nX resolver are configured to detect the rotational position based on the change in the facing area between the rotor core and the salient pole, thereby making them less susceptible to the error factor.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Figure 1
FIG. 1 is a configuration diagram of an embodiment of the present invention. In FIG. 1, (a) is a plan view and (b) is a cross-sectional view of the X 1OX 2 portion of (a). In FIG. 1, 10 is a rotor and 20 is a stator.

In the rotor 10, 11 is a disk-shaped rotor plate having a hole at its center, 12 and 1
3 is the center of the rotor plate 11 on the same surface as the center O of the rotor plate
It is a rotor core attached together with. Rotor core 1
Reference numeral 2 has a ring shape, and the ring width changes two cycles for one round of the ring. The rotor core 13 also has a ring shape, and the ring width is 1 for one round of the ring.
It changes in 3 steps every 20 °.

In the stator core 20, reference numeral 21 is a stator plate formed in a disk shape and having a hole in the center. FIG. 1A shows a state in which the rotor plate 11 is removed. At a position facing the rotor core 12 on the stator plate 21, 16 at intervals of 22.5 ° along the circumferential direction.
Individual salient poles 22 1 to 22 16 are formed. Among these salient poles, 22 1 and 22 2, 22 3 and 22 4, 22 5 and 22 6, 22 7 and 22 8 are 0 ° salient pole group, 90 ° salient pole group, and 180 ° salient pole group. , 270 ° salient pole groups are respectively formed. Also, 229 and 2210, 2211 and 2212, 22
13 and 2214, 2215 and 2216 are also 0 ° salient pole groups,
A 90 ° salient pole group, a 180 ° salient pole group, and a 270 ° salient pole group are formed, and four types of salient pole groups are repeatedly arranged twice. 23
Reference numerals 1 to 2316 denote coils wound on the salient poles 22 1 to 2216, respectively. The coils 231 to 2316 are film-like coils in which a spiral pattern is formed on an insulating substrate.
Copper, for example, is used as the conductor forming the spiral pattern. Among the 16 coils, the coils wound around the same salient pole group are connected in series, whereby the inductance of the coils wound around four salient poles in one salient pole group is averaged. Since the salient poles are composed of four types of salient pole groups, a total of 4N (N is an integer) are provided. At the position facing the rotor core 13 on the stator plate 21, the salient pole 2
4 is attached. A specific configuration of the salient pole portion 24 is shown in FIG. FIG. 2 is a view of the salient pole 24 as viewed from the radial direction. In FIG. 2, the salient pole 24 is U-shaped and constitutes a magnetic circuit together with the rotor core 13. A coil 25 is wound around one arm of the U-shaped salient pole 24. The coil may be wound around both arms. An insulating member 26 is made of a non-magnetic material and insulates the salient pole 24 from the stator plate 21.

Returning to FIG. 1, 30 is an exciting means,
Ecos coil wound around salient pole group and 180 degree salient pole group
AC voltage of ωt (E: voltage amplitude, ω: angular velocity, t:
The coil wound around the 90 ° salient pole group and the 270 ° salient pole group is excited with an AC voltage of E sin ωt. Three
1 is an AC voltage (E 1 cos ω 1 t
1: Excitation of voltage amplitude, ω1: Angular velocity,) Reference numeral 40 is a detecting means for detecting the rotational position of the rotor 10 within 1/2 rotation from the induced voltage of the coils 231-2316, 41 is the rotor 10 with 1/2 resolution as the resolution from the induced voltage of the coil 25. Is a detecting means for detecting the rotational position of the. Reference numeral 50 is a calculation unit for calculating the absolute rotational position of the rotor based on the detection signals of the detection means 40 and 41.

Next, the operation of such a magnetic resolver will be described. First, the detection operation of the nX resolver will be described. The ring width of the rotor core 12, that is, the core width W changes according to the following equation. W = w 0 + Δw sin2θ θ: Rotation angle of rotor w 0: Initial value, Δw: Amplitude that gives change in core width Rotor core and salient pole facing area is core width W and salient pole width (constant value) Since it is multiplied by, it is given by the following equation. S = S 0 + ΔS · sin2θ S 0: initial value, ΔS: amplitude giving a change in area Here, the facing area in the 0 ° salient pole group is two salient poles 22 1 arranged with a mechanical angle of 22.5 °. , 22 2 and two salient poles 229, 2210 arranged with a mechanical angle of 180 ° to these two salient poles are averaged. When the mechanical angle of 180 ° is separated, the core width of the rotor core changes by one cycle, so the average value of the facing area of the four salient poles 22 1, 22 2, 229, 2210 is Given. S1 = S0 + ΔS {sin2θ + sin2 (θ + 22.5 °) + sin2θ + sin2 (θ + 22.5 °)} / 4 = S0 + ΔS'sin2θ (1) ΔS ': constant value Similarly, 90 ° salient pole group, 180 ° salient Pole group, 270 °
The facing area in the salient pole group is given by the following equation. S 2 = S 0 + ΔS ′ · cos 2θ (2) S 3 = S 0 −ΔS ′ · sin 2θ (3) S 4 = S 0 −ΔS ′ · cos 2θ (4) 0 ° salient pole group, 90 ° salient pole Group, 180 ° salient pole group, 270 °
4 coils connected in series with salient pole groups
The coils are 0 phase, cos 0 phase, sin 180 phase, and cos 180 phase. Since the inductance of each phase coil is proportional to the facing area of the rotor core and salient pole, sin0
The inductances L 1, L 2, L 3, L 4 of the coils of the phase, cos0 phase, sin180 phase, and cos180 phase are given by the following equations. L 1 = L 0 + ΔL sin2θ L 2 = L 0 + ΔL cos 2θ L 3 = L 0 −ΔL sin 2θ L 4 = L 0 −ΔL cos 2θ
Exciting the 0-phase coil with an alternating voltage of Ecosωt,
Since the s0-phase coil and the cos180-phase coil are excited by an AC voltage of Esinωt, sin0-phase, cos0-phase,
The voltage signals V 1, V 2, V 3 and V 4 appearing in the sin 180 phase and cos 180 phase coils are given by the following equations. V1 = asin2 [theta] cos [omega] t V2 = bcos2 [theta] sin [omega] t V3 = -csin2 [theta] cos [omega] t V4 = -dcos2 [theta] sin [omega] t a, b, c, d: constant

Here, the arithmetic unit 40 has the structure shown in FIG. 3, for example. In FIG. 3, the calculation unit 40 includes voltage signals V 1 to V 1 which appear in each coil by the amplifiers A 1 to A 3.
The following equation is calculated for V 4. V = (V1-V3) + (V2-V4) = Acos ([omega] t- [phi] -2 [theta]) [phi] = arctan {(b + d) / (a + c)} A: constant Therefore, the signal V has a rotor of 1 When rotated, the phase is modulated for two cycles. The low-frequency component is extracted by the low-pass filter 41 from the signal V thus obtained, and the comparator 4
The waveform is shaped at 2. The excitation signal Ecosωt generated by the excitation means 30 is also waveform-shaped by the comparator 43. The phase difference counter 44 measures the phase difference −φ−2θ between the phase modulation signal from the comparator 42 and the reference signal from the comparator 43 which is not phase modulated. As a result, the measured value of the phase difference counter 44 changes by two cycles when the rotation angle θ of the rotor changes by 360 °.

Next, the operation of the 1X resolver will be described. Since the ring width of the rotor core 13 changes in three steps every 120 °, the inductance of the coil 25 is also 1
Each time 0 rotates 120 °, it changes in 3 steps. Therefore,
The signal level of the detection signal of the detection means 41 changes in three stages according to the rotational position of the rotor.

From the above, the measured value of the phase difference counter 44 and the detection signal of the detecting means 41 are as shown in FIG. The calculation unit 50 detects in what cycle the measured value of the phase difference counter 44 is the measured value based on the level of the detection signal of the detecting means 41. Thereby, the rotation is detected with the resolution of 1/2 rotation. And detected 1
The rotational position within 1/2 rotation is detected from the count of the phase difference counter 44. With this, the absolute rotational position is obtained. In the embodiment, the measured value of the phase difference counter 44 changes by two cycles per rotation of the rotor, whereas the level of the detection signal of the detection means 41 changes in three steps per rotation of the rotor. It is possible to determine what cycle the measured value is.

In the embodiment, the case where the nX resolver is the 2X resolver has been described, but the value of n may be an integer of 3 or more. Generally, with an nX resolver, 1X
The level of the detection signal of the resolver is changed in 1 / (n + 1) stages. Further, the core width of the rotor core is not limited to the sine function, and may be any width that changes according to another periodic function.

[0016]

According to the present invention, 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 of both resolvers are also arranged on the same plane of the stator plate. There is. As a result, flattening can be realized even if the 1X resolver and the nX resolver are combined. Further, since both the 1X resolver and the nX resolver detect the rotational position based on the change in the facing area between the rotor core and the salient pole,
Compared to the eccentric type magnetic resolver that detects the rotational position based on the minute change in the gap between the stator and the stator, it is less susceptible to error factors such as temperature change and moment load. Further, the 1X resolver need not be of high detection accuracy, as long as the output level changes in 1 / (n + 1) stages.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

2 is a main part configuration diagram of the magnetic resolver of FIG. 1. FIG.

3 is a configuration diagram of a main part of the magnetic resolver of FIG.

FIG. 4 is an operation explanatory view of the magnetic resolver of FIG.

[Explanation of symbols]

 10 rotor 11 rotor plate 12, 13 rotor core 20 stator 21 stator plate 22 1 to 2216, 24 salient pole 23 1 to 2316, 25 coil 30, 31 exciting means 40, 41 detecting means 50 Arithmetic section

Claims (1)

Claim: What is claimed is: 1. A 1X resolver in which the phase of a detection signal is modulated by 360 ° each time the rotor makes one rotation, and the rotor is 1 / n.
It has an nX resolver in which the phase of the detection signal is modulated by 360 ° for each rotation (n is an integer), and the rotational position is detected with the resolution of 1 / n rotation by the detection signal of the 1X resolver, and the detected 1 / The rotational position within n rotations is the nX
In a magnetic resolver that detects the absolute rotational position by detecting it with the detection signal of the resolver, the rotor plate has a disc shape and the ring shape has a ring width that changes in n + 1 steps for one rotation of the ring. In addition, the first rotor core attached to the rotor plate, and the ring shape, the ring width of which changes by n cycles for one round of the ring, are attached to the rotor plate. A second rotor core, a disk-shaped stator plate, and a rotor plate mounted on the stator plate at a position facing the first rotor core. The area of the portion that overlaps the first rotor core changes depending on the rotational position.
Of the salient pole and the stator plate, which is mounted on the stator plate at a position facing the second rotor core and overlaps with the second rotor core depending on the rotational position of the rotor. The second where the area changes
Salient poles, first and second coils respectively wound on the first and second salient poles, exciting means for exciting the first and second coils, and induction of the first coil. The voltage is detected, and based on the detected voltage, the inductance of the first coil changes according to the area of the portion where the first salient pole and the first rotor core overlap each other. A first detection circuit that outputs a detection signal having any one of the signal levels of 1., and a second coil that detects the induced voltage of the second coil and that detects the induced voltage. Second detection circuit that outputs a detection signal of the rotational position within 1 / n rotation by utilizing the fact that the inductance of the circuit changes according to the area of the portion where the second salient pole and the second rotor core overlap. And the second detection circuit based on the output level of the first detection circuit. The circuit detects the position detected by the circuit in 1 / n rotation in which cycle, and also detects the detected cycle number and the rotational position within 1 / n rotation detected by the second detection circuit. A magnetic resolver comprising: an arithmetic unit for determining the absolute rotation of the rotor;