JP2008051633A - Differential capacitance type resolver - Google Patents

Abstract

The present invention provides a thin, high-accuracy and high-speed response configuration by differential detection of capacitance using a dielectric rotor rotatably provided between stator electrodes and a current probe connected between the stator electrodes. An object of the present invention is to obtain a differential capacitance type resolver.
A differential capacitive resolver according to the present invention is provided with a dielectric rotor (6) between stator electrodes (12) provided on an inner surface (10) of an electromagnetic shield frame (1), and a stator electrode (12). 1) or 2 current probes (23) connected to), and an excitation voltage (E _x ) input and a differential voltage output (E ₀ ) are obtained via the current probe (23).
[Selection] Figure 1

Description

  The present invention relates to a differential capacitance type resolver, and in particular, a thin and high-capacity differential detector using a differential detection of capacitance using a dielectric rotor rotatably provided between stator electrodes and a current probe connected between the stator electrodes. The present invention relates to a novel improvement for achieving a configuration of accuracy and high-speed response.

Conventionally used thin resolvers of this type include the configuration using the rotary transformer shown in FIGS. 5 and 6 and the configuration of the variable reluctance resolver of Patent Document 1 shown in FIG. Can do.
That is, in the conventional casing shown in FIGS. 5 and 6, the resolver unit 2 and the rotary transformer unit 3 are superposed along the axial direction.

  In addition, a resolver portion 2 of another conventional configuration shown in FIG. 7 includes a ring-shaped stator 5 having a resolver stator coil 4 and a ring-shaped rotor 6 which is provided in the stator 5 and does not have a coil. Has been.

Further, the wiring diagrams of the resolver windings in FIGS. 5, 6 and 7 are configured as shown in FIG. 9, and the excitation windings R1 and R2 are composed of one phase, and the output winding S1 on the detection side. ˜S4 is composed of two phases.
Further, an output voltage curve and an output voltage equation by the output windings S1 to S4 are shown in FIG.

US Pat. No. 5,920,135 Electronic Technology March 2002, pages 53-57

Since the conventional thin resolver is configured as described above, the following problems exist.
That is, in the conventional configuration disclosed in FIGS. 5 and 6, since the resolver part and the rotary transformer part are superposed in the axial direction, the resolver itself is thicker (16 mm is minimum), and is flatter. It was extremely difficult to form.
In the other conventional configuration shown in FIG. 7, only a resolver stator coil is required as a coil. However, since the resolver stator coil wound around the stator protrudes on both sides of the stator, an insulating cover for insulating the resolver stator coil is used. In addition, a coil cover or the like is required, and the thickness of the stator is increased (10 mm is minimum), and it is extremely difficult to form a flat shape as described above. Further, since the rotor does not have a coil, the detection accuracy is limited.
Further, in the conventional configuration, rotation detection is performed by changing the gap permeance between the outer periphery of the rotor and the inner periphery of each magnetic pole of the stator.
In addition, since the stator has an integral structure, the magnetic field distribution generated by the excitation winding is affected by the mechanical position of the detection rotor pole.
Further, since the electrostatic resolver disclosed in the electronic technology of Non-Patent Document 1 described above uses the capacitance change itself, the capacitance variation due to temperature and the like is large, and the signal processing circuit becomes complicated, which is practical. It was difficult to convert.

  A differential capacitance type resolver according to the present invention includes a plurality of stator electrodes disposed on the inner surface of an electromagnetic shield frame at predetermined angular intervals and opposed to each other, and between each stator electrode and each stator electrode. Is provided in a non-contact state so as to be rotatable, and a dielectric rotor formed by changing the eccentricity or radius in a sine wave shape of the rotation angle with respect to a circle formed by the inner peripheral edge of each stator electrode, and each stator electrode An excitation voltage is supplied between the stator electrodes facing each other via the current probe, and in proportion to a change in the coupling area between the stator electrodes and the dielectric rotor. The configuration is such that the differential current between the stator electrodes flowing between the stator electrodes changes, and the change in the differential current is converted into a voltage by the current probe to output a differential voltage output. Also, the current probe is composed of one piece, and the differential voltage output is outputted from the current probe, and the current probe is composed of two pieces, and the current probes are mutually connected. The differential voltage output is output in series when connected in series, and the current probe includes a linkage current detection type magnetic ring and a coil.

Since the differential capacitance type resolver according to the present invention is configured as described above, the following effects can be obtained.
That is, a dielectric rotor is provided between each stator electrode, and the detection of the change in the linkage current based on the excitation input supplied between each stator electrode via the current probe is detected by the current probe to obtain a differential voltage output. Therefore, it is possible to obtain a rotation detection signal that is thin and has high accuracy and high speed response.
In addition, it is superior in high-frequency characteristics as compared with the conventional magnetic detection method.
Further, the error accuracy can be reduced by using the interlinkage current detection method and the differential capacitance detection method together.
Further, it is possible to detect from 1X to nX by decentering the dielectric rotor or changing its shape along the sine of the rotation angle along the radial direction.
Further, since the interlinkage current detection is realized by the current probe, the simplification of the signal processing electronic circuit can be realized.

  The present invention uses a current probe connected between a stator rotor electrode and a dielectric rotor rotatably provided between the stator electrodes, and has a thin, high-accuracy and high-speed response structure based on electrostatic capacitance differential detection. An object is to provide a capacitive resolver.

Hereinafter, preferred embodiments of a differential capacitive resolver according to the present invention will be described with reference to the drawings.
The same reference numerals are used for the same or equivalent parts as in the conventional example.
1 and 2, what is denoted by reference numeral 1 is an electromagnetic shielding frame made of an electromagnetic shielding material as a whole having a circular (or square) box shape, and the inner surfaces 10 of the electromagnetic shielding frame 1 facing each other. 11, a pair of stator electrodes 12 are arranged facing each other and spaced apart.

  Each of the stator electrodes 12 is arranged at a rotation angle position of, for example, every 90 degrees when viewed in a plan view. Each stator electrode 12 has a substantially sector shape, and its inner peripheral edge 12a and outer peripheral edge 12b are continuous. Although not shown, the connecting lines are configured to be perfect circles having different diameters.

In the gap 13 between the stator electrodes 12, for example, a dielectric rotor 6 made of a perfect circular disk made of a dielectric material such as polyethylene is rotatably provided with the shaft 6A being eccentric. As shown in FIGS. 1 and 2, when the dielectric rotor 6 rotates eccentrically, the outer periphery 6a of the rotor is configured to change in and out of the stator electrode 12. The coupling areas S ₀ and S ₁₈₀ where the dielectric rotor 6 and the dielectric rotor 6 overlap in the axial direction are changed.
The capacitance in the coupling area S ₁₈₀ is C ₁₈₀ = ε · S ₁₈₀ / d, and the capacitance in the coupling area S ₀ is C ₀ = ε · S ₀ / d (where d is each stator electrode) 12).

Wherein each stator electrodes 12, an excitation input (exciting voltage) E _x and the pair of magnetic ring 20 and the current probe 23 including coil 21. for performing the excitation is connected.

When two current probes 23 connected to each stator electrode 12 are used as shown in FIGS. 1 and 4, one current probe 23 may be used as shown in FIG.
First, when there is one current probe 23 as shown in FIG. 3, excitation input (excitation voltage) E _x (E _x = sinωt) is supplied to each stator electrode 12 through the current probe 23, and from this current probe 23 Is configured to output a differential voltage output E ₀ [E ₀ = m · (I ₁₈₀ −I ₀ )].

Next, the case where outputting a differential voltage output E _0.
First, in the case of a differential capacitance detection type resolver that detects interlinkage current using one current probe 23 in FIG. 3, the following equations (1) to (6) are used.

Here, _Ex is the excitation voltage (excitation input), and ω is the angular velocity of the excitation power supply.
(5), (6) of _{ω, ε, d, I 0} , I 180 from _{E x} is a constant varies in proportion to _{S 0, S 180.}
Therefore, if the differential area of S ₀ and S ₁₈₀ changes with the sine function of the rotation angle θ of the dielectric rotor 6, the differential current of I ₀ and I ₁₈₀ also changes with the sine function of the rotation angle θ.
I _0, the figures to obtain a differential current of _{I 180} 3, to obtain a differential output voltage by converting the differential current of _{I 0, I 180} to voltage using a current probe as in FIG.
In FIG. 1, I ₀ and I ₁₈₀ are inserted into one current probe in opposite phases, and the differential current of I ₀ and I ₁₈₀ is converted into a differential voltage to obtain an output.
In FIG. 2, I ₀ and I ₁₈₀ are converted into voltages V ₀ and V ₁₈₀ using two current lobes connected in series with opposite phases, respectively, to obtain a differential voltage.

Next, when the above-described coupling areas S ₀ and S ₁₈₀ are changed by a sine function of the rotation angle θ of the dielectric rotor 6, there are the following two methods.
First, as described above, in the case where the rotation center of the dielectric rotor 6 is eccentric, the difference in coupling differential area between the stator electrode 12 and the dielectric rotor 6 installed at the positions of 0 ° and 180 ° is the rotation angle. The sine wave changes.
Therefore, a known 1X resolver can be realized by using the configuration shown in FIGS.

Further, as described above, when the radius of the dielectric rotor 6 is changed in a sinusoidal shape of the rotation angle, the radius of the dielectric rotor 6 is changed in a sinusoidal shape of the rotation angle, for example, non-true such as a heart or a clover. A stator electrode 12 having a circular shape and provided at positions of 0 ° and 180 ° of the resolver is used, and a deployment angle D _t of the stator electrode 12 is _expressed by the following seven formulas.
D _t = π / n (7)
Where n is the number of poles of the resolver.
Due to the above-described dielectric rotor 6 and each stator electrode 12, the difference in coupling differential area between the stator electrode 12 and the dielectric rotor 6 installed at the positions of 0 ° and 180 ° changes in a sine wave shape of the rotation angle. An nX resolver can be realized.

It is a block diagram which shows the differential capacitive type resolver by this invention. It is sectional drawing of the principal part of FIG. It is a block diagram at the time of using one current probe. It is a block diagram at the time of using two current probes. It is a half sectional view showing a conventional resolver. FIG. 6 is a plan view of FIG. 5. It is sectional drawing which shows another prior art example. It is explanatory drawing which shows the output voltage curve and output voltage equation of the conventional resolver. It is a wiring diagram of a conventional resolver.

Explanation of symbols

First electromagnetic shielding frame 6 dielectric rotor 6a rotor outer peripheral edge 10, 11 the inner surface 12 stator electrode 12a in the periphery 12b outer peripheral edge 13 void 20 magnetic ring 21 coil 23 current probe _{S 0, S 180} bonded area

Claims (4)

A plurality of stator electrodes (12) disposed at predetermined angular intervals on the inner surfaces (10, 11) of the electromagnetic shield frame (1) and opposed to each other, and between the stator electrodes (12) and the respective The stator electrode (12) is rotatably provided in a non-contact state, and the eccentricity or radius is changed in a sine wave shape of the rotation angle with respect to the circle formed by the inner peripheral edge (12a) of each stator electrode (12). A dielectric rotor (6), and a current probe (23) connected to each stator electrode (12),
Excitation voltage (E _x ) is supplied between the stator electrodes (12) facing each other through the current probe (23), and the coupling area between the stator electrodes (12) and the dielectric rotor (6) The differential current between the stator electrodes flowing between the stator electrodes (12) changes in proportion to the change in (S ₀ , S ₁₈₀ ), and the change in the differential current is converted into a voltage by the current probe (23). The differential capacitance type resolver is configured to output a differential voltage output (E ₀ ). The differential capacitive resolver according to claim 1, wherein the current probe (23) is composed of a single piece, and the differential voltage output (E ₀ ) is output from the current probe (23). . The current probe (23) is composed of two, according to claim 1 wherein each said current probe (23), wherein the differential voltage output are connected in series (E ₀₎ is outputted from each other Differential capacitance resolver.   The differential capacitance type resolver according to any one of claims 1 to 3, wherein the current probe (23) includes an interlinkage current detection type magnetic ring (20) and a coil (21).

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