JPH10300411A - Non-contact potentiometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precise output characteristic close to a regulated straight line or curve as occasion demands, and provide a large output with little output fluctuation by forming a coil into a winding shape curved substantially circularly around a driving shaft. SOLUTION: When a rotor 6 is rotated, the inductance of coils 8a, 8b is changed, and the change portion is taken out as output signal. According to this device, a specific output characteristic differed from in the past can be provided. An output characteristic of a wide straight part can be provided by curved coils 8a, 8b and the fan-shaped rotor 6. An output characteristic of a secondary curve-shaped specific curve can be provided by deformed curved coils 8a, 8b and the fan-shaped rotor 6. Thus, a precise output close to a regulated straight line or curve can be provided as occasion demands. The coils 8a, 8b are arranged above and under the rotor 6, whereby the output fluctuation by a temperature change or a play of a drive shaft 4 can be minimized, and a relatively large output can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact potentiometer used for various machine tools, measuring devices, control devices and the like.

[0002]

2. Description of the Related Art First, the structure of a conventional non-contact potentiometer will be described with reference to FIGS. In FIG. 1, 1 is a non-contact potentiometer as a whole, 2 is a case (outer case), and a drive shaft 4 is rotatably supported by a bearing 3 provided at the center of the upper surface of the case 2. .

The drive shaft 4 is retained by retaining rings 5a and 5b fitted inside and outside the case 2, and a lower end thereof is connected and fixed to a rotor 6 inside the case 2.

The rotor 6 is a disk made of a conductive metal, and is connected to the drive shaft 4 at a portion eccentric from the center by ΔS as shown in FIG.

A substrate 7 is fixed to a lower portion of the case 2, and a pair of left and right coils 8 a and 8 b opposed to the lower surface of the rotor 6 with a small gap are provided on the substrate 7.
Are arranged symmetrically with respect to.

The coils 8a and 8b are formed of cylindrical portions 10a and 10b in cylindrical cores 9a and 9b having magnetic permeability.
b, and when the rotor 6 is eccentrically rotated by the drive shaft 4, the left and right coils 8a, 8a
The structure is such that the rotor 6 alternately faces b.

Further, on the substrate 7, a high frequency oscillation circuit 12 for applying a high frequency to the coils 8a and 8b,
Each electronic component of the detection circuit 13 for extracting a change in inductance 8b as a signal is mounted. Further, from the substrate 7, a terminal 14, which is a signal output part, protrudes outside.

The coils 8a and 8b are connected to a high-frequency oscillation circuit 12 and a detection circuit 13, as shown in FIG. In this configuration, the high-frequency oscillation circuit 1 is connected to the coils 8a and 8b.
When a high frequency is applied to the rotor 6, an eddy current is generated in the rotor 6. When the rotor 6 is eccentrically rotated by the drive shaft 4 in this state, the area of the rotor 6 facing the coils 8 a and 8 b changes. Changes to the coil 8a,
8b changes. The change is detected by the detection circuit 13 and taken out as an output signal.

[0009]

In the conventional non-contact potentiometer constructed as described above, only an output having a fixed characteristic can be obtained, and the output fluctuates due to the effect of temperature change and backlash of the drive shaft. There was a problem that it was easy. The present invention has been made to solve such a problem.

[0010]

In order to achieve the above object, the present invention provides a drive shaft, a rotor connected to the drive shaft, and a coil facing the rotor with a small gap.
In a non-contact potentiometer that changes the inductance of the coil by rotating the rotor by the drive shaft and extracts the change as a signal, the coil is wound in a substantially arc shape around the drive shaft. It was formed into a shape. Further, in this configuration, the coils are arranged vertically above and below the rotor.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 4 and 5 show the most preferred embodiment of the present invention. Here, portions corresponding to those of the conventional example of FIGS. 1 to 3 described above are denoted by the same reference numerals, and description thereof is omitted.

In the non-contact potentiometer 1 of the present embodiment, the coils 8a and 8b are arranged vertically with the rotor 6 interposed therebetween. That is, in the configuration of the present example, in addition to the configuration of the conventional example described above, the upper substrate 11 is fixed inside the case 2 in parallel with the lower substrate 7, and the upper substrate 11 A pair of left and right coils 8a and 8b facing each other with a gap are provided corresponding to the coils 8a and 8b on the lower substrate 7 side.

Each of these coils 8a and 8b is formed by laminating and winding, and formed in a band shape and fixed in a ring shape on a substrate. Alternatively, the substrate may be formed by laminating on a substrate by printing, vapor deposition, sputtering or the like.

The coils 8a and 8b are formed in a winding shape that is curved in a substantially arc shape (bow shape) around the drive shaft 4, as is apparent from FIG. In the case of this example, the coils 8a and 8b are formed in a curved shape having a uniform width over the entire length. FIG. 6 shows another example of the shape of the coils 8a and 8b. In this case, the coils 8a and 8b are formed into deformed curved shapes whose widths are quantitatively different.

On the other hand, the rotor 6 is made of a metal plate having good conductivity or a non-conductive metal plate and a metal having good conductivity is applied by plating or the like. As is evident, the coil 8a or 8b has a semicircular fan shape that covers the coil 8a or 8b.
8b.

As the rotor 6, as shown in FIG. 8, a disk-shaped insulating plate 6a having a conductive metal plate 6b fixed to the upper and lower surfaces of a semicircular portion thereof may be employed. Good.

When the rotor 6 is rotated, the inductance of the coils 8a and 8b changes, and the change is taken out as an output signal. Here, the contactless potentiometer according to the present invention is different from the conventional one. Different special output characteristics can be obtained.

FIG. 9 is a graph comparing the output characteristics of the conventional non-contact potentiometer and the output characteristics of the non-contact potentiometer according to the present invention. That is, in the graph of FIG. 9, (A) shows the output of a non-contact type potentiometer including the circular coils 8a and 8b and the disk-shaped eccentric rotor 6 as shown in the conventional example. In this case, the output characteristic is sinusoidal. It becomes a waveform close to a wave.

FIG. 5B shows the output of a non-contact potentiometer composed of curved coils 8a and 8b and a fan-shaped rotor 6 as shown in FIG. 5. In this case, a wide output characteristic of a linear portion is obtained.

FIG. 6C shows the output of a non-contact type potentiometer comprising coils 8a and 8b having a deformed curved shape and a fan-shaped rotor 6 as shown in FIG. 6. In this case, the output characteristic of a special quadratic curve is shown. Is obtained.

Therefore, in the non-contact potentiometer according to the present invention, it is possible to obtain an accurate output close to a prescribed straight line or curve as required.

Also, in this non-contact potentiometer, the coils 8a and 8b are arranged above and below the rotor 6, so that output fluctuations due to temperature changes and backlash of the drive shaft 4 are small, and a relatively large output is obtained. be able to.

Further, in the non-contact potentiometer, since the core conventionally used for increasing the output is not used, the cost can be reduced.

The embodiment of the non-contact potentiometer according to the present invention has been described above. However, it is needless to say that the present invention is not limited to the above-described configuration, but can adopt various other embodiments. .

[0025]

As described above, according to the non-contact potentiometer of the present invention, an accurate output characteristic close to a prescribed straight line or curve can be obtained as required, and a change in temperature and play of the drive shaft can be reduced. Output fluctuation due to the influence is small, a relatively large output can be obtained, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a conventional non-contact potentiometer.

FIGS. 2A and 2B are structural views of main parts, in which FIG. 2A is a plan view and FIG.
Is a longitudinal side view.

FIG. 3 is an electric circuit diagram of the same.

FIG. 4 is a vertical sectional side view showing a non-contact potentiometer according to the present invention.

FIGS. 5A and 5B are structural views of a main part, in which FIG. 5A is a plan view and FIG.
Is a longitudinal side view.

FIG. 6 is another example of the shape of the coil.

FIG. 7 is an explanatory view of a shape of a rotor, (A) is a plan view,
(B) is a side view.

8A is a plan view showing another example of the shape of the rotor, FIG.
(B) is a side view.

FIG. 9 is a graph comparing output characteristics of a conventional non-contact potentiometer and a non-contact potentiometer according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Non-contact potentiometer, 2 ... Case, 4 ... Drive shaft, 6 ... Rotor, 8a, 8b ... Coil

Claims (2)

[Claims] 1. A drive shaft, a rotor connected to the drive shaft, and a coil facing the rotor with a small gap, the inductance of the coil being changed by rotating the rotor by the drive shaft. A non-contact potentiometer wherein the change is taken out as a signal, wherein the coil has a winding shape curved into a substantially circular arc centered on the drive shaft. 2. The non-contact potentiometer according to claim 1, wherein said coil is disposed vertically above and below said rotor.