JPH05256710A - Multiple component force detector - Google Patents

Abstract

PURPOSE:To obtain a detector of multiple components of force which is highly accurate with high reproducibility and simple in structure without generating interferences among components of force, thereby to reduce the manufacturing cost. CONSTITUTION:Four flat beams 11-14 are placed between a measuring flange 1 and a fixed flange 2. A first group of strain gauges 111-126 are attached to the front and rear surfaces at both ends of each beam. A second group of strain gauges 211-218 are attached to the front and rear surfaces at the central part of each beam. These strain gauges are suitably selected and connected in a bridge, so that multiple components of force can be selectively detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates each component of the force acting on a beam from the other component, and electrically detects it as a change in electrical resistance of a strain gauge attached to the surface of the beam. Perhaps related to a force detector.

[0002]

2. Description of the Related Art In recent years, ships, vehicles, aircraft and the like have come to be used under extremely severe conditions with the rapid progress of technology. Therefore, in order to advance research and development on these vehicles, it is required to precisely measure what kind of force and moment are actually acting as external factors. Therefore, a force detector has been used conventionally.

In this type of detector, a strain gauge is attached to the surface of the beam for elastically fixedly connecting the measurement side flange and the fixed side flange. The magnitude of the component force acting on the measurement side flange is calculated from the strain generated in the beam.The bridge circuit formed by the strain gauge emits an unbalanced output signal due to the change in the electrical resistance of the gauge, and this signal value is It takes advantage of being proportional to the component force.

However, in order to detect the component force of the external force in the predetermined direction from the component components other than the above with the above structure and detect it with high accuracy, the position where the strain gauge is attached, the shape, the dimension, the material of each beam, Since extremely strict conditions such as the arrangement position are imposed, it is extremely difficult to practically suppress the detection error due to the interference between the component forces without any problem.

[0005]

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, have a simple structure, reduce the manufacturing cost, and prevent each component from interfering with other components. The present invention is to provide a strain gauge that produces an accurate output and a bridge circuit configured by these strain gauges.

[0006]

According to the present invention, the above-mentioned problems are the fixed side flange, the measurement side flange facing the fixed side flange, and the central axis of both flanges.
It is fixed parallel to the axis, has a cross section with one side sufficiently thinner than the other, and has wide side faces parallel to the ZX plane.
Four pairs of flat plate-shaped beams that form two pairs with the same spacing on the X plane and two narrow sides with the same spacing with respect to the ZY plane, and the front and back surfaces of both ends of the beam, respectively. From the first strain gauge group that is attached in pairs and detects the axial strain of the beam, and the second strain gauge group that is attached to the center of the beam axial direction and that detects the axial strain of the beam And the force F _y in the Y direction formed by the first strain gauge group
Is solved by a force detector formed by a bridge for detecting the moment and a bridge for detecting the moment M _X around the X axis formed by the second strain gauge group.

Further, the above-mentioned problems are solved by the present invention.
Fixed side flange and measurement side facing this fixed side flange
Parallel to the flange and the Z-axis, which is the central axis of both flanges
It is fixed, and one side has a cross section that is sufficiently thin compared to the other side.
Has a wide side surface parallel to the ZX plane,
Form two pairs with the same spacing, and the narrow side becomes the ZY plane.
On the other hand, four flat plate-shaped plates that form two pairs with the same spacing
And the front and back sides of the beam at both ends.
Detecting the axial distortion of the beam pasted as
The strain gauge group and the VI
The second strain gauge group that detects strain in the axial direction of the arm.
The force F in the Y direction formed by the first strain gauge group_yDetect
The bridge around the X-axis formed by the second strain gauge group.
Statement M _XDetecting the bridge, and the two formed by
Maybe one of the force detectors has a common axis to the other
F made by rotating 90 ° and fixed connection_x,F_y,M
_X,M_{y ,}Solved by a force detector that may detect the four force components of
Has been.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing embodiments.

As shown in FIG. 1, the force and moment acting on any one point 0 of the object are F in the X, Y, Z orthogonal coordinate system.
It can be separated into six independent forces and moments _X, F _Y, F _Z, M _X, M _{Y, and} M _Z. In the following description, this symbol will be used for description.

2a and 2b schematically show the mechanical structure of the sensing part of the present invention. As shown in the figure, four flat plate-shaped beams 1 are provided between the fixed-side flange 2 and the measuring-side flange 1 that connects a member (not shown) for measuring the component force.
1 to 14 are fixedly connected. These beams 11 to 1
4 each have a rectangular cross section of the same shape in which the thickness t is much smaller than the width B. The thickness direction of these beams is the Y axis, the width direction is the X axis, and the vertical direction of the beams is Z.
It is oriented parallel to the axis. As shown in FIG. 2B, the beams 11 to 14 are arranged in mirror symmetry with respect to the XZ plane and the YZ plane including the axial center of the flanges 1 and 2, respectively. Therefore, the deformation of the beam is flexible in the Y-axis direction and rigid in the X-axis direction.

FIGS. 3a, 3b and 3c show various examples of attaching gauges for detecting the force F _Y and the moment M _X.

The strain gauges 111 to 126 are attached near both ends of each of the beams 11 to 14 in pairs on both surfaces and in a direction in which the deformation strain in the Z-axis direction can be measured. When these strain gauges 111 to 126 are connected to the bridge shown in FIG. 4 (hereinafter, each strain gauge is represented by a resistance in the electric circuit diagram, and the same reference numerals as those in FIGS. 3a to 3d are attached),
Since the flexible deformation of the beam can be detected, only the component force F _Y can be measured with high sensitivity.

The strain gauge connection capable of measuring only the component force F _Y can also be achieved by the bridge circuit shown in FIG. 5 or 6.

Further, according to FIGS. 3b and 3c, the strain gauges 211 to 218 are paired on both surfaces near the center of the beams 11 to 14 in the axial direction, and the direction in which the deformation strain in the Z-axis direction can be measured. And pasted. The bridge connection capable of measuring the moment M _X using these strain gauges 211 to 218 can use any of the configurations shown in FIGS. 7, 8 and 9.

Next, near the axial center of the beams 11 to 14 described above, as shown in FIG.
The strain gauges 211 ′ to 2 are tilted at an angle of 45 ° with respect to the vertical direction of 4, and are paired so as to intersect each other at 90 ° on the front surface and the back surface.
18 'is pasted. Here, the strain gauge shown by the dotted line in FIG. 3d corresponds to that attached to the back surface.

In the case of the configuration shown in FIG. 2, the measurement side flange Z
When a moment M _Z is applied around the axis, each beam 11-1
No. 4 causes bending strain and shear strain. At that time, since the rigidity in the X direction is overwhelmingly larger than the rigidity in the Y direction, the moment M _Z can be expressed as M _Z ≈ F _MZ xL _Y , as can be understood from FIG. 2b. Here, L _Y is the beams 11 and 12
Is the distance between the beam and the beams 13, 14. Therefore, by connecting the strain gauges 211 'to 218' to the bridge arrangement shown in FIG. 10, FIG. 11 or FIG. 12, the moment M _Z can be taken out as an output signal of the bridge.

To simultaneously measure M _X and M _Z , longitudinal strain gauges 211 to 216 and 45 ° strain gauge 2 are arranged side by side in the width direction at the axial center of the surface of each beam 11 to 14.
11 'to 216' are adhered (not shown), and any one of FIGS. 7 to 9 is used for the former strain gauge, and one of FIGS. 10 to 12 is used for the latter strain gauge. .. Alternatively, the strain gauges 211 to 216 and the strain gauges 211 ′ to
If you use the corresponding rosette gauge as 216 ',
The paste space can be saved. In addition to the above configuration,
Strain gauges 111 to 1 bonded to both ends of the beams 11 to 14
If the bridges shown in FIGS.
_A three-component force detector capable of measuring _Y, M _{X and} M _Z can be formed.

Further, two three-component force detectors shown in FIGS. 3a to 3d are prepared. One of the detectors has a common center axis of the flange with respect to the other detector, and 90 degrees around this axis. °
When rotated and fixedly coupled, a new single detector can be formed. That is, it is possible to form a five-component force detector of F _x, F _Y, M _X, M _{Y and} M _Z.

[0019]

As described above, the multi-component force detector according to the present invention can take out independent component force without interfering with other component force in spite of its simple structure.
The manufacturing cost is low, it is easy to use, and highly accurate component force measurement is possible.

[Brief description of drawings]

FIG. 1 is a perspective view of an orthogonal coordinate system that defines a component force.

FIG. 2 is a side view (a) of the multi-component force detector according to the present invention and a plan view (b) viewed from a line segment IIb-IIb ′.

3A and 3B are schematic layout diagrams showing a position where a strain gauge is attached to a beam, and a plan view (a) viewed from a line segment IIa-IIa ', a side view (b) viewed from the left in FIG. 3A, and FIG. FIG. 3C is a side view of the case of the first sticking method seen from below (c) and a side view of the case of the second sticking method seen from below in FIG. 3A (d).
Is.

FIG. 4 is a connection diagram showing a bridge configuration of a strain gauge for measuring F _Y.

FIG. 5 is a connection diagram showing a bridge configuration of a strain gauge for measuring F _Y.

FIG. 6 is a connection diagram showing a bridge configuration of a strain gauge for measuring F _Y.

FIG. 7 is a connection diagram showing a bridge configuration of a strain gauge for measuring M _X.

FIG. 8 is a connection diagram showing a bridge configuration of a strain gauge for measuring M _X.

FIG. 9 is a connection diagram showing a bridge configuration of a strain gauge for measuring M _X.

FIG. 10 is a connection diagram showing a bridge configuration of a strain gauge for measuring M _Z.

FIG. 11 is a connection diagram showing a bridge configuration of a strain gauge for measuring M _Z.

FIG. 12 is a connection diagram showing a bridge configuration of a strain gauge for measuring M _Z.

[Explanation of symbols]

 1 measurement side flange, 2 fixed side flange, 11-14 beam, 111-126 beam end strain gauge, 211-218 beam center strain gauge,

Claims (2)

[Claims] 1. A fixed-side flange, a measuring-side flange that faces the fixed-side flange, and a section that is fixed parallel to the Z-axis, which is the central axis of both flanges, and has one side that is sufficiently thinner than the other side. And has wide sides parallel to the ZX plane and two pairs with the same spacing on the ZX plane, and narrow sides forming two pairs with the same spacing on the ZY plane. Beam, the first strain gauge group for detecting the axial strain of the beam, which is attached to the front surface and the back surface at both ends of the beam, respectively, and the first strain gauge group attached to the center of the beam in the axial direction. A second strain gauge group that detects axial strain, a bridge that detects the Y-direction force F _y formed by the first strain gauge group, and a moment M about the X axis that is formed by the second strain gauge group a bridge for detecting the _X, in which is formed Maybe force detector characterized and. 2. A fixed-side flange, a measuring-side flange facing the fixed-side flange, and a section that is fixed parallel to the Z-axis, which is the central axis of both flanges, and has one side sufficiently thinner than the other side. And has wide sides parallel to the ZX plane and two pairs with the same spacing on the ZX plane, and narrow sides forming two pairs with the same spacing on the ZY plane. Beam, the first strain gauge group for detecting the axial strain of the beam, which is attached to the front surface and the back surface at both ends of the beam, respectively, and the first strain gauge group attached to the center of the beam in the axial direction. A second strain gauge group for detecting axial strain, a bridge for detecting the Y-direction force F _y formed by the first strain gauge group, and a moment M about the X axis formed by the second strain gauge group a bridge for detecting the _X, in two to be formed Characterized Maybe force detector of one fixed connected commonly rotated 90 ° from each other on the axis relative to the other and to fabricated _{F x, F y, M X} , to detect M _y, 4 component of the And maybe a force detector.