JPH01110203A - Angle of rotation detector - Google Patents

Abstract

PURPOSE:To detect an angle of rotation with a simple-structured apparatus, by electrically connecting a plurality of electrodes to an elongation type conductive elastomer at positions separated at intervals. CONSTITUTION:While an elongation type conductive rubber 1 is not twisted, the conductive rubber 1 is large in electric resistance as no tensile stress is caused in the conductive rubber 1. But when an angle of rotation to be detected is inputted into an input shaft 4, the conductive rubber 1 is twisted accordingly, which causes a tensile stress in the conductive rubber 1 corresponding to the angle of rotation to reduce electric resistance of the conductive rubber 1 according to the angle of rotation. This enables detection of an angle of rotation through a change in the electric resistance of the conductive rubber 1 between electrodes 6 and 7.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention utilizes an elongated conductive elastomer such as an elongated conductive rubber whose electrical resistance changes depending on the magnitude of the elongation when elongated. This article relates to a rotation angle detection device that detects a rotation angle (in this specification, a rotation angle detection device refers not only to a device whose ultimate purpose is to detect a rotation angle, but also to a device whose ultimate purpose is to detect a rotation angle, but also to a device that detects other factors such as torque through a rotation angle). (This also includes devices that detect physical quantities.)

[Conventional technology]

Conventionally, rotation angle detection devices include potentiometers,
Rotating differential transformers, synchronizers, resornos, shaft encoders, pulse generators, etc. were used.

[Problem that the invention seeks to solve]

However, the conventional rotation angle detection device has problems in that it has a relatively complicated structure, occupies a large space, and has high manufacturing costs.

[Purpose of the invention]

The present invention was made to solve the above-mentioned conventional problems, and has a very simple structure, occupies a very small space, and can reduce manufacturing costs. An object of the present invention is to provide a rotation angle detection device.

[Means for solving problems]

The rotation angle detection device according to the present invention includes an elongated conductive elastomer that can give the rotation angle to be detected as torsional deformation, and a plurality of electrodes that are electrically connected to the conductive elastomer at mutually spaced positions. This is what happens.

[Effect]

When the elongated conductive elastomer is not twisted, no tensile stress is generated in the conductive elastomer, so the conductive elastomer has a high electrical resistance.

However, when the rotation angle to be detected is given as a twist, a tensile stress is generated in the conductive elastomer in accordance with the rotation angle, so that the electrical resistance of the conductive elastomer decreases in accordance with the rotation angle.

Therefore, the rotation angle can be detected through a change in the electrical resistance of the conductive elastomer between the electrodes.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 shows a first embodiment of the invention. In this embodiment, 1 is a round rod-shaped elongated conductive rubber.

This conductive rubber 1 has a characteristic that its electrical resistance changes when it is stretched, and FIG. 2 shows this stretchable conductive rubber 1.
It is a characteristic diagram showing the relationship between elongation rate and electrical resistance change (
However, the length is 20.0 mm, the width is 10.0 mm, and the thickness is 0.0 mm.
(Characteristics when made into a 3 mm sheet). As is clear from this characteristic diagram, the stretchable conductive rubber 1 has a characteristic that the electrical resistance is large when no stretching is applied, but the resistance decreases as it stretches.

An elongated conductive rubber having such characteristics can be obtained by, for example, as disclosed in Japanese Patent Application No. 62-203856, conductive silicone rubber made by mixing carbon black and graphite is cross-linked in advance, and then, It can be created by impregnating 5 to 50% of silicone oil that is compatible with this conductive silicone rubber.

A rubber holder 2 is fixed to one end of the conductive rubber 1, and a rubber holder 3 is fixed to the other end with an adhesive. The rubber holder 2 is fixed to a fixed object 9 so as not to rotate. An input shaft 4 is provided on the rubber holder 3 so as to be concentric with the conductive rubber 1, and this input shaft 4 is rotatably supported by a bearing 5.

Electrodes 6 and 7 are attached to the conductive rubber 1 near the rubber holder 2 at appropriate intervals, so that these electrodes 6 and 7 are also electrically connected to the conductive rubber 1. There is. These electrodes 6.7 can be attached to the conductive rubber 1 by, for example, providing holes in the conductive rubber 1 and press-fitting the electrodes 6 and 7 into the holes, or by attaching the electrodes 6.7 to the conductive rubber 1 using conductive rubber. This can be done by bonding with adhesive.

Next, the operation of this embodiment will be explained.

When the elongated conductive rubber 1 is not twisted, no tensile stress is generated in the conductive rubber 1, and therefore the conductive rubber 1 has a high electrical resistance.

However, when the rotation angle to be detected is input to the input shaft 4, the conductive rubber 1 is twisted by that amount.

Then, a tensile stress is generated in the conductive rubber 1 according to the rotation angle, so that the electrical resistance of the conductive rubber 1 becomes smaller according to the rotation angle.

14 - Therefore, the rotation angle can be detected through the change in electrical resistance of the conductive rubber 1 between the electrodes 6 and 7.

Further, by checking the spring constant of the conductive rubber 1 in advance, the torque can also be detected from the rotation angle.

In this embodiment, the electrodes 6 and 7 are provided near the rubber holder 2, but these electrodes 6 and 7 may be provided in other locations. However, when the conductive rubber 1 is twisted, a large twist tends to occur in the central part of the conductive rubber 1 in the longitudinal direction. Although it may not be possible to do it stably,
If the electrodes 6 and 7 are installed avoiding the longitudinal center of the conductive rubber 1 as in the case of this embodiment, such a problem can be prevented.

FIG. 2 shows a second embodiment of the present invention, in which an elongated conductive rubber 1
The second embodiment is the same as the first embodiment except that it has a hollow cylindrical shape.

In this example as well, in the same manner as in the previous example,
- The rotation angle can be detected, and furthermore, the torque can be detected from this rotation angle.

4 to 6 show a third embodiment of the present invention. In this embodiment, reference numeral 11 is an elongated sheet-like elongated conductive rubber having the same elongation-electrical resistance characteristics as the conductive rubber 1 of each of the above embodiments.

Reference numeral 12.13 denotes a rubber holding plate, which holds one end of the conductive rubber 1 between the bolts 14 and nuts 15.
It is tightened by. These rubber retaining plates 12.
13 is fixed to a fixed object 30 so as not to rotate. 16 is a rubber holder having a U-shaped cross section;
1 is tightened with a bolt 17 and a nut 18 with the other end thereof sandwiched therebetween. An input shaft 19 is provided on the rubber holder 16 so as to extend in the length direction of the conductive rubber 11, and the input shaft 19 is rotatably supported by a bearing 20.

Electrodes 20.21 are attached at appropriate intervals to a portion of the conductive rubber 11 near the rubber holding plate 12.13, so that these electrodes 20.21 are also electrically connected to the conductive rubber 11. has been done.

In this embodiment as well, the rotation angle can be detected in the same manner as in the previous embodiments, and furthermore, the torque can also be detected from this rotation angle.

In each of the above embodiments, an example in which an elongated conductive rubber was used as the elongated conductive elastomer was shown, but in the present invention, an elongated conductive elastomer other than rubber may be used.

Furthermore, the components and manufacturing method of the elongated conductive rubber that can be used in the present invention are not limited to those disclosed in Japanese Patent Application No. 173856/1982.

Furthermore, the rotation angle detection device according to the present invention is capable of detecting not only the rotation angle and torque but also other physical quantities that can be derived from the rotation angle.

〔Effect of the invention〕

As described above, the rotation angle detection device according to the present invention has excellent effects such as a very simple structure, the ability to occupy a very small space, and a very low manufacturing cost. That's what you get.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a first embodiment of the rotation angle detection device according to the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the elongation rate and the change in electrical resistance of the conductive rubber used in the embodiment. 3 is a front view showing a second embodiment of the rotation angle detection device according to the present invention, FIG. 4 is a front view showing a third embodiment of the rotation angle detection device according to the present invention, and FIG. 5 is a front view showing the third embodiment of the rotation angle detection device according to the present invention. FIG. 6 is a front view showing a state in which a rotation angle is given to the embodiment. 1... Stretchable conductive rubber, 6, 7... Electrode, 11...
- Stretchable conductive rubber, 20.21...electrode. Patent Applicant: Asahi Sugimoto (and 1 other person) Agent: Izumi Omori, Patent Attorney Figure 2 Figure 4 Figure 6

Claims (1)

[Claims] An elongated conductive elastomer (an elastomer whose electrical resistance changes depending on the magnitude of the elongation when elongated) is provided with the rotation angle to be detected as torsional deformation, and the conductive elastomer is placed at positions spaced apart from each other. A rotation angle detection device comprising a plurality of electrically connected electrodes.