JPS60228938A - Electrostatic capacity type friction force detector - Google Patents

Abstract

PURPOSE:To make it possible to measure the magnitude and direction of friction force acting on a flat surface, by forming the flat surface, on which friction force is acted, from the friction force testing body connected to the elastomer of which the periphery is fixed to a frame and converting the change in a position to that in electrostatic capacity. CONSTITUTION:A friction force testing body 3 is connected to the flat plate shaped elastomer 2 fixed to a frame 1 at the periphery thereof and the support 4 of the electric insulator mounted to the under surface of said testing body 3 is displaced corresponding to the direction and magnitude of friction force F. Further, fan shaped electrode plates (b), (c), (d), (e) are arranged directly under an electrode plate (a) so as to hold minute gaps and to have electrostatic capacity in the gaps with the electrode (a). When arbitrary friction force F is acted on the surface of the testing body 3, a support rod 5 is inclined and the gaps between the electrode (a) and the electrode plates (b), (c), (d), (e) corresponding to the direction and magnitude of said friction force F change. The change in the electrostatic capacity corresponding to the change in said gaps is electrically measured to make it possible to measure the direction and magnitude of the friction force acted on the surface of the testing body 3 corresponding to the inclination direction and magnitude thereof of the support rod 5.

Description

DETAILED DESCRIPTION OF THE INVENTION In the cross-sectional view of the apparatus in FIG.

When the frictional force F acts on this specimen surface in the direction of the arrow,
The test body 3 is displaced in the direction of the same arrow, and the position of the electrical insulator support plate 4 attached to the lower surface of the test body is displaced in accordance with the direction and magnitude of F. This displacement causes the support rod 5 to tilt in the direction of arrow D with the tip end 6 of the pivot as a fulcrum. Note that the electrode plate b. c. d. and e
is a plan view of this device. 1 and a cross-sectional view.
As shown in FIG. 2, an electrode plate a fixed perpendicularly to the center of the support rod 5 is placed on an electrically insulating disc 7 so that these electrode plates do not come into contact with each other or with the support rod 5. The center lines of electrode plates b and c and the center lines of electrode plates d and e lie on the same plane. c. d. e
electrode plate b. is arranged perpendicular to the center of the circle formed by electrode plate b. c. d.
e are attached so as to maintain a minute gap between each.

Electrode plates a and b, a and c, a and d, and a and e are installed so as to each have a capacitance.

For example, when the frictional force F acts on the surface of the test specimen 3 of the apparatus in the direction of the arrow shown in FIG. 2, the support rod 5 moves as shown in FIG. The electrode plate a, which is tilted in the direction of arrow D shown in FIG. 2 and thereby fixed to the support rod 5, also tilts in accordance with the inclination of the support rod 5.

When the frictional force F does not act on the electrode plate a, that is,
Compared to when a is not tilted, the gap between electrode plates a and b becomes smaller, and the gap between electrode plates a and c becomes larger. According to this change in gap, the capacitance between electrode plates a and c decreases, and the capacitance between electrode plates a and b increases, but between electrode plates a and d and electrode plate a. The difference in capacitance between the two and e does not change in this state.

Therefore, by electrically measuring the difference between the capacitance between electrode plates a and b and the capacitance between electrode plates a and c in this state, the inclination of electrode plate a can be determined. . This slope depends on the frictional force F acting on the surface of the test specimen 3. If the elastic constant of the elastic body 2 in the direction of the frictional force is measured in advance, the magnitude of the frictional force F in this direction can be measured as a change in capacitance. Furthermore, since the center lines of the pair of electrode plates b and c and the pair of electrode plates d and e are arranged on orthogonal lines, the support rod 5 is arranged as shown in FIG. When a frictional force F that is inclined in a direction perpendicular to the direction of arrow D shown in 2 acts on the surface of the test specimen 3 of this frictional force detector, a phenomenon similar to that described above occurs between each electrode plate. Therefore, from the difference between the capacitance between electrode plates a and d and the capacitance between electrode plates a and e, the frictional force F in this case can be measured as a change in capacitance.

Furthermore, even if a friction force F in an arbitrary direction acts on the surface of the test specimen 3 of the friction force detector and the support rod 5 is inclined in the direction of F, the direction and magnitude of the inclination of the support rod 5 will be changed. Accordingly, changes in capacitance occur between electrode plates a and b, a and c, a and d, and a and e, so that differences in capacitance between a and b, a and c, and a and By measuring the difference in capacitance between d, a, and e, the magnitude of the friction force acting on the surface of the test specimen 3 of the friction force detector according to the direction of inclination of the support rod 5 and the magnitude of the inclination can be determined. Can measure height and direction.

[Brief explanation of drawings]

The figure shows an embodiment of the invention. figure. 1 shows a plan view of the device, showing the electrode structure inside the device. figure. 2
is a cross-sectional view of the device. a, b, c, d, e...electrode plates. 1...Frame. 2... Flat elastic body. 3...Friction force test specimen. 4...Support plate.
5...Support rod. 6...Tip of pivot. 7...Electric insulator disc. D...
...Arrow in the direction of displacement. F...Frictional force. Patent applicant Kiyoshi Takahashi

Claims (1)

[Claims] In a friction force measuring device, a plane on which frictional force acts is created by a friction force test specimen connected to an elastic body whose periphery is fixed to a frame, and the position is determined depending on the friction force acting on the surface of the test specimen. A transmission mechanism is attached to this frictional force test specimen that changes its position, and a detection plate is attached to the transmission mechanism, and a change in position that depends on the frictional force of this detection plate is detected between the detection plate and A friction force detection device that measures the friction force acting on the surface of a friction force test object by converting it into a change in capacitance formed by the other detection plate fixed to the frame of the device.