JPH09159401A - Strain measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen the measuring range of a strain measuring instrument so that the instrument can measure a large strain. SOLUTION: In a strain measuring instrument 10, a pair of fixtures 14 and 16 which are stuck to the surface 12 of a platy rubber material 12 at a prescribed interval is provided. One end sections of hooks 22 and 24 are respectively engaged with the through holes 18 and 20 of the erected parts 14B and 16B of the fixtures 14 and 16. The other end sections of the hooks 22 and 24 are respectively engaged with through holes 28 and 30 bored near both end sections of a rectangular gauge sticking plate 26. Strain gauges 32 are stuck to both the front and rear surfaces of the plate 26 while the phosphor bronze plate is bent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a strain measuring device,
In particular, it relates to a strain measuring device for measuring a large strain of a rubber material used for a tire.

[0002]

2. Description of the Related Art Conventionally, when measuring the strain of an object to be measured, a sheet-like strain gauge 72 is directly attached to the object to be measured 70 as shown in FIG.

[0003]

However, in such a strain measuring device, the measurement limit is generally the strain gauge 72.
Is less than 10% of the length L of the resistance element 72A.
For this reason, as shown in FIG.
Direction, the length L1 of the resistance element 72A is
If it exceeds 10% of the length L before distortion shown in Fig. 3, the strain gauge 72 may be separated from the object 70 to be measured, the resistance element 72A of the strain gauge 72 may be disconnected, and the measurement may not be performed. .

In view of the above facts, the present invention has an object to provide a strain measuring device capable of measuring a large strain by greatly expanding the measuring range.

[0005]

A strain measuring apparatus according to the present invention as set forth in claim 1, which is attached to the surface of the object to be measured, at least one of which is capable of absorbing the extension of the object to be measured, and a bending member. And a strain gauge attached to the gauge attachment plate, and the strain measurement means is provided between the pair of fixing fittings. .

Therefore, the strain of the gauge-attached plate, which is smaller than the strain of the measured object, is absorbed by the strain of the measured object by at least one of the pair of fixing metal fittings, and the strain is measured from the measured value. Obtain the strain of the measured object.

According to a second aspect of the present invention, in the strain measuring device according to the first aspect, the fixing fitting is formed of a phosphor bronze plate.

Therefore, the strain of the gauge-attached plate, which is smaller than the strain of the measured object, is absorbed by at least one of the pair of fixing fittings formed of the phosphor bronze plate, The strain is measured with a strain gauge, and the strain of the object to be measured is determined from this measurement value.

According to a third aspect of the strain measuring apparatus of the present invention, a pair of fixing fittings attached to the surface of the object to be measured, a curved gauge attaching plate, and a strain gauge attached to the gauge attaching plate. A strain measuring means consisting of, and an extension absorbing means capable of absorbing the extension of the object to be measured, the strain measuring means and the extension absorbing means are connected and installed between the pair of fixing fittings. It has a feature.

Therefore, the strain of the object to be measured is absorbed by the extension absorbing means via the pair of fixing fittings, and the strain of the gauge sticking plate which is smaller than the strain of the object to be measured is measured by the strain gauge. The strain of the measured object is obtained from the measured value.

According to a fourth aspect of the present invention, in the strain measuring apparatus according to the third aspect, the extension absorbing means is a spring.

Therefore, the strain of the object to be measured is absorbed by the expansion of the spring through the pair of fixing fittings, and the strain of the gauge attaching plate, which is smaller than the strain of the device to be measured, is measured by the strain gauge. The strain of the measured object is obtained from the measured value.

According to a fifth aspect of the present invention, in the strain measuring apparatus according to the third aspect, at least one of the pair of fixing fittings can absorb the extension of the object to be measured.

Therefore, the strain of the gauge-attached plate, which is smaller than the strain of the measured object, is absorbed by at least one of the pair of fixing fittings and the extension absorbing means, and the strain of the measured object is reduced.
The strain is measured with a strain gauge, and the strain of the object to be measured is determined from this measurement value.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the strain measuring apparatus of the present invention will be described with reference to FIGS.

As shown in FIG. 1, in the strain measuring apparatus 10 of the first embodiment, the surface 12A of the rubber plate material 12 as the object to be measured is made of, for example, a phosphor bronze plate at a predetermined interval. Elastically deformable pair of fixing brackets 14 and 16
Is affixed. Each of the fixtures 14 and 16 has a rectangular plate-shaped base 14A and 16A attached to the surface 12A of the rubber plate 12, and a rectangular plate-shaped member that stands substantially vertically from the center of the base 14A and 16A. Erection part 14
B and 16B.

Construction parts 14B and 16 of the fixing brackets 14 and 16
Through holes 18 and 20 are formed near the upper end of B, and one ends of hooks 22 and 24 are engaged with these through holes 18 and 20, respectively. The other ends of the hooks 22 and 24 are through holes 28 and 3 formed in the vicinity of both ends of the rectangular gauge sticking plate 26, respectively.
0 is engaged. The gauge attachment plate 26 has a structure in which the strain gauges 32 are attached to the front surface and the back surface in a curved state of a phosphor bronze plate.

Next, the operation of the first embodiment will be described.
In the strain measuring device 10 of the first embodiment, first, one fixing metal fitting, for example, the fixing metal fitting 14 is attached to the surface 12A of the rubber plate material 12, and then the end fixing metal fitting, for example, the fixing metal fitting 16 is attached. Paste. In this state, as shown in FIG. 2, when the rubber plate member 12 is distorted in the direction of arrow F in FIG. 2, the erected portions 14B and 16B of the respective fixing fittings 14 and 16 are elastically deformed in the directions approaching each other and , Fixing bracket 14,
Hooks 22 and 24 are provided by 16 installation parts 14B and 16B.
Both ends of the gauge sticking plate 26 are pulled in mutually opposite directions via. The tensile force elastically deforms the curved gauge attaching plate 26 in the extending direction, and the strain gauges 32 attached to the front surface and the back surface of the gauge attaching plate 26 are distorted.

Therefore, by connecting the strain gauge 32 attached to the front surface and the back surface to a well-known Wheatstone bridge circuit 52 and connecting this to a strain measuring device, the strain of the object to be measured 12 is indirectly measured, From this measured amount, the actual strain of the rubber plate material 12 can be converted based on a calibration value described later.

As described above, the strain measuring device 1 of the first embodiment
At 0, the strain of the strain gauge 32, which is smaller than the actual strain of the rubber plate member 12, is measured by the bending of the installation portions 14B and 16B of the fixing brackets 14 and 16, and the actual strain of the rubber plate member 12 is measured based on the measured amount. Since the strain is converted, the amount of deformation of the strain gauge 32 itself can be suppressed.

Therefore, even when measuring a large strain,
Since the strain gauge 32 does not peel off from the gauge sticking plate 26 or the resistance element of the strain gauge 32 is not broken, the measurement range can be greatly expanded and a large strain can be measured.

Next, a second embodiment of the strain measuring apparatus of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 3, in the strain measuring apparatus 40 of the second embodiment, a coil as an extension absorbing means is provided in the through hole 18 of the installation portion 14B of the fixing fitting 14 and the through hole 28 of the gauge sticking plate 26. Both ends 42A and 42B of the spring 42 are engaged with each other.

Next, the operation of the second embodiment will be described.
In the strain measuring device 40 of the second embodiment, first, one fixing metal fitting, for example, the fixing metal fitting 14 is attached to the surface 12A of the rubber plate material 12, and then a state in which a slight tension is applied to the coil spring 42. At the end of the fixing bracket, for example, the fixing bracket 16
Paste. In this state, as shown in FIG. 4, when the rubber plate member 12 is distorted in the direction of arrow F in FIG.
The erected portions 14B and 16B of 16 are bent by elastic deformation in a direction toward each other, and the erected portions 14B and 16B of the fixing fittings 14 and 16 pull the coil spring 42 and the gauge sticking plate 26 in opposite directions. The tensile force elastically deforms the coil spring 42 and the curved gauge attaching plate 26 in the extending direction, and the strain gauges 32 attached to the front surface and the back surface of the gauge attaching plate 26 are distorted.

Therefore, by connecting the strain gauges 32 attached to the front surface and the back surface to a well-known Wheatstone bridge circuit 52 and connecting this to a strain measuring device, the strain of the measured object 12 is indirectly measured, From this measured amount, the actual strain of the rubber plate material 12 can be converted based on a calibration value described later.

In this way, the strain measuring device 4 of the second embodiment is
At 0, the strain of the strain gauge 32, which is smaller than the actual strain of the rubber plate member 12, is measured due to the bending of the installation portions 14B and 16B of the fixing brackets 14 and 16 and the expansion of the coil spring 42.
Since the actual strain of the rubber plate material 12 is converted based on this measured amount, the amount of deformation of the strain gauge 32 itself can be suppressed.

Therefore, even when measuring a large strain,
Since the strain gauge 32 is not peeled off from the gauge sticking plate 26 or the resistance element of the strain gauge 32 is not broken, the measurement range can be further expanded as compared with the first embodiment, and a large strain can be measured. .

Next, how to obtain the calibration value will be described with reference to FIGS. As shown in FIG. 5, first, the caliper 50
To one of the main scale jaws 50A, one fixing metal piece of the strain measuring device 40, for example, the fixing metal piece 14 is pasted, and then the fixing metal piece on the end side in a state in which the coil spring 42 is slightly tensioned,
For example, the fixture 16 is attached to the slider jaw 50B.

Next, as shown in FIG. 6, a pair of strain gauges 32 are attached to the front and back surfaces of the gauge attaching plate 26.
Is connected to the Wheatstone bridge circuit 52 and connected to the strain measuring instrument 54.

In this state, the caliper 50 main scale jaw 5
0A and the slider jaw 50B are gradually widened, and a point where slight tension is applied to the coil spring 42 of the strain measuring device 40 is set as a reference point (displacement 0 mm), and an output value (με) at intervals of 5 mm. To read. Further, the detection range is set within the elastic deformation area of the coil spring 42, and both the going direction for widening the interval and the returning direction for narrowing the interval are measured, and the calibration value k is calculated from the result.

For example, when the measurement result is as shown in Table 1 below, the calibration value k is k = 11.225 με / mm.

[0032]

[Table 1] Note that the strain measurement device 10 of the first embodiment also calculates the calibration value in the same manner.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are included in the scope of the present invention. It is clear to a person skilled in the art that is possible. For example, only one of the pair of fixing brackets 14 and 16 may be configured to be able to absorb the expansion of the measured object. Further, the extension absorbing means may be another elastic member such as rubber instead of the coil spring 42.

[0034]

According to the strain measuring apparatus of the present invention as set forth in claim 1,
Strain measurement consisting of a pair of fixtures attached to the surface of the object to be measured, at least one of which can absorb the elongation of the object to be measured, a curved gauge attachment plate, and a strain gauge attached to the gauge attachment plate. Since the strain measuring means is provided between the pair of fixing metal fittings, the measuring range can be greatly expanded and a large strain can be measured.

According to the present invention described in claim 2, in the strain measuring device according to claim 1, since the fixing metal member is formed of a phosphor bronze plate, the same effect as in claim 1 can be obtained.

The strain measuring apparatus of the present invention as set forth in claim 3 comprises a pair of fixing fittings attached to the surface of the object to be measured, a curved gauge attaching plate and a strain gauge attached to the gauge attaching plate. Since the strain measuring means and the extension absorbing means capable of absorbing the extension of the object to be measured are provided, and the strain measuring means and the extension absorbing means are connected and installed between the pair of fixing brackets, the measurement range is further widened. It has an excellent effect that a larger strain can be measured.

The present invention according to claim 4 is the strain measuring apparatus according to claim 3, wherein the extension absorbing means is a spring.
The same effect as in claim 3 is obtained.

According to a fifth aspect of the present invention, in the strain measuring apparatus according to the third aspect, at least one of the pair of fixing fittings can absorb the extension of the object to be measured. It has an excellent effect that a larger strain can be measured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a strain measuring device according to a first embodiment of the present invention.

FIG. 2 is an operation explanatory view of the strain measuring device according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a strain measuring device according to a second embodiment of the present invention.

FIG. 4 is an operation explanatory view of the strain measuring device according to the second embodiment of the present invention.

FIG. 5 is a perspective view showing how to obtain a calibration value of the strain measuring apparatus according to the second embodiment of the present invention.

FIG. 6 is a circuit diagram showing how to obtain a calibration value of the strain measuring apparatus according to the second embodiment of the present invention.

FIG. 7 is a perspective view showing a strain measuring device according to a conventional embodiment.

FIG. 8 is an operation explanatory view of a strain measuring device according to a conventional embodiment.

[Explanation of symbols]

 10 strain measuring device 12 rubber plate material (measured object) 14 fixing metal fitting 16 fixing metal fitting 26 gauge sticking plate 32 strain gauge 40 strain measuring device 42 coil spring (extension absorbing means)

Claims (5)

[Claims] 1. A pair of fixing fittings, which are attached to the surface of the object to be measured, at least one of which can absorb the elongation of the object to be measured, a curved gauge attaching plate, and an instrument attached to the gauge attaching plate. A strain measuring device comprising: a strain gauge; and a strain measuring device, wherein the strain measuring device is installed between the pair of fixing fittings. 2. The strain measuring device according to claim 1, wherein the fixing member is formed of a phosphor bronze plate. 3. A strain measuring means comprising: a pair of fixing fittings attached to the surface of the object to be measured; a curved gauge attaching plate; and a strain gauge attached to the gauge attaching plate; A strain measuring device comprising: a stretch absorbing means capable of absorbing the body's extension; and the strain measuring means and the stretch absorbing means are connected and installed between the pair of fixing fittings. 4. The strain measuring device according to claim 4, wherein the extension absorbing means is a spring. 5. The strain measuring device according to claim 3, wherein at least one of the pair of fixing fittings can absorb the extension of the measured object.