JPS622101A - Strain gauge - Google Patents

Abstract

PURPOSE:To measure rapidly and easily dynamic strain deformations of human body,by using strain gauges adhered with resistance wire strain gauges an top of crests of a ribbon-type corrugated thin metallic sheet. CONSTITUTION:The strain gauge is composed of a ribbon body 1 of thin metallic sheet bent into corrugations and resistance wire strain gauges 2 adhered on top of the corrugations. When measuring, the strain gauge is adhered to the specimen with adhesive compound or tape. On this occasion as the ribbon body 1 is of a corrugated form, it follows a strain in a flexible manner and the amount of strain is detected by the strain gauge 2. Thus, dynamic strain deformations of human body on the occasion of design of wooden pattern of shoes and dress style can be measured rapidly and easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a strain measuring instrument that can quickly and easily measure dynamic strain deformation of a measurement target.

In particular, the present invention relates to a strain measuring instrument suitable for application when the object to be measured, such as a human body, is flexible and has a large amount of deformation.

[Prior art 1] When designing the shoe shape or the buzzer-in design of the garment model, it is natural that the dimensions of the model (human body) in a static state must be accurately measured, but it is also necessary to accurately measure the dimensions of the model (human body) in a static state. In order to manufacture shoes and clothing that are comfortable to wear and have excellent functionality, it is necessary to accurately measure the amount of deformation, or distortion, of each part of the human body from a resting state in a dynamic state where the model performs various movements. should be measured.

Furthermore, such distortions should be continuously measured not only when the model is in a fixed pose, but also when the model changes from time to time due to the actual motion of the model.

Conventionally, methods for measuring the distortion of an object include a photo analysis method using a high-speed camera, a moiré draft analysis method, and a method using a resistance wire strain gauge.

[Problems to be solved by the invention] In principle, the photographic analysis method can perform three-dimensional measurements and has good accuracy, but it requires advanced knowledge and know-how for experiments and analysis, and it is difficult to obtain results. It costs a lot of money and takes a lot of time. Therefore, there is a problem that this photo analysis method lacks practicality.

Although the moiré draft analysis method can sufficiently analyze two-dimensional distortions, it has problems in that the analysis takes time and accuracy is low. Furthermore, three-dimensional strain analysis is impossible. Therefore, this moiré draft analysis method can actually only be used for qualitative observations.

The measurement method using a resistance wire strain gauge enables accurate and rapid strain measurement of highly rigid objects such as building members, civil engineering structural members, and metal mechanical parts. However, when the object to be measured is flexible, such as a human body, the deformation of the object is not properly transmitted to the gauge, so accurate strain measurement cannot be performed.

Moreover, resistance wire strain gauges can only measure strain amounts of several thousand at most.For this reason, it is impossible to directly attach a 5-resistance wire strain gauge to the human body and measure the strain. .

[Means for Solving the Problems] The strain measuring instrument of the present invention includes a thin-walled metal strip bent in a waveform, and a resistance wire strain gauge attached to the wave peak of the strip. Configured with the necessary features.

[Operation] In order to measure the strain meter of the object using the strain meter of the present invention,
This strain measuring device is attached to the surface of the object using adhesive or adhesive tape.

The deformation of the object is first transmitted to the metal band of the strain measuring instrument of the present invention. Since this metal band is curved in a waveform, it flexibly follows and deforms elastically even when the object undergoes large deformation. A resistance wire strain gauge is attached to the peak portion of the wave of this metal band, and the amount of deformation of the metal band can be detected accurately and quickly by this resistance wire strain gauge.

However, since the amount of deformation of the metal band corresponds to the amount of deformation of the object, by measuring the amount of deformation of this band with a resistance wire strain gauge, it is possible to measure the strain of the object such as a human body. can be detected correctly while quickly following the dynamic deformation of the object.

[Example] Examples will be described below with reference to the drawings.

FIG. 1 is a perspective view of a strain measuring instrument according to an embodiment of the present invention. 2.

In this embodiment, the thin metal band l has a long side portion 1a,
It has a rectangular shape having a short side portion 1b and a leg portion 1c,
The resistance wire strain gauge 1 is attached to the long side 1a. In the figure, 2a is a lead wire of the gauge 2.

In order to measure the strain on an object using such a strain measuring instrument, as shown in FIG. The part 1b is attached to the object 3 using adhesive or adhesive tape (not shown).
firmly attached to the surface. At this time, it is preferable that the installation direction of the strain measuring device coincides with the maximum deformation direction of the object.

Therefore, when the object 3 deforms, the distance d between the short sides 1b changes. For example, when the surface of the object 3 deforms in the direction of elongation as shown in FIG. 3, the distance d increases by 1 (d+
Δd), this causes a minute elongation of δ on the long side la. This elongation deformation amount is detected by the resistance wire strain gauge 2. On the other hand, when the surface of the object 3 is deformed in the shrinking direction as shown in FIG. 4, the distance d between the short sides 1b becomes smaller (d-Δd), and the long sides 1a undergo shrinkage deformation. This amount of deformation is detected by the resistance wire strain gauge 2. (Note that FIGS. 3 and 4 schematically show the deformation of the band 1,
The deformation of the strip 1 is shown to be larger than it actually is.

) This resistance wire strain gauge 2 does not have stress relaxation characteristics and has linearity between strain and voltage change. Moreover, since the voltage characteristics change extremely quickly depending on the amount of deformation of the object 3, it is possible to perform strain measurement accurately and quickly.

The resistance wire strain gauge of the present invention can measure the amount of deformation of the object because the metal band is deformed even when the surface of the object undergoes deformation behavior such as expansion or contraction. It is.

In addition, before carrying out the actual measurement, the distortion of the distance d between the short sides 1b and 1. By determining the relationship with the change in the voltage characteristics of the resistance wire strain gauge 2 in advance, it is possible to immediately measure the amount of deformation of the object from the change in the characteristics of the resistance wire strain gauge 2. FIG. 5 is a schematic diagram showing the relationship between the strain Δd/d of the distance d between the short sides 1b and the voltage change ΔV of the resistance wire strain gauge, and as shown by the line segment A, a linear relationship is established.

This change in the distance d corresponds to the deformation of the surface of the object, since the band l is firmly attached to the object 3.

FIG. 6 is a diagram showing the operating characteristics of the strain measuring device according to the embodiment shown in FIG. 1 when the strain measuring device is attached to a human body and the amount of deformation of the skin on the surface of the human body is measured. In FIG. 6, it is assumed that the human body, which was initially in a stationary state, starts moving at time 1+, reaches maximum deformation at time t2, then performs a return movement, returns to its original position at time t3, and then remains in a stationary state. . Short side 1 of the strain measuring instrument at this time
The distortion Δd/d of the distance d between the curves B becomes a mountain shape as shown by the curve B. There is a linear relationship between Δd/d and Δ■' as mentioned above, so if the line showing this linear relationship is line segment C, the change ΔV in the voltage characteristics of the resistance wire strain gauge 2 is This is shown by curve R. Therefore, by detecting changes in the voltage characteristics of the resistance wire strain gauge as shown by the curve R, it is possible to accurately detect the deformation of the human skin in response to human body motion.

In the embodiment shown in FIG. 1, a strain measuring instrument having a rectangular metal band l is shown, but in the present invention,
A metal band 4 curved in the shape of a sine curve as shown in FIG.
Alternatively, a band 5 having a shape of connected trapezoids as shown in FIG. 8 may be used (in addition, a resistance wire strain gauge 2 is attached to the wave apex of the band 4.5). ) However, the shape shown in Figure 1 allows for the most accurate measurement. Naturally, in the present invention, the shape and dimensions of the metal band are selected so that it can flexibly follow the deformation of the object and can be elastically deformed.

In the case of the strain measuring instrument shown in Fig. 1, the dimensions of each part of the metal band l vary depending on the nature of the object to be measured, the amount of deformation, etc., but when measuring human skin, one leg 1c The height of the current is about 5 to 100 mm, and the height of the strip is about 1llii.
It is preferable that l 2 is about 1 to 10 mm, and the distance d between the short sides 1b is about 5 to 100 mm.Also, regarding the length of the short sides 1b (3), it is preferable to set the band l to about 1 to 10 mm. It is preferable to make it as small as possible as long as it can be firmly fastened. Note that l+, 412. By setting d within the above range, it is possible to obtain a band having a stiffness and deformation range that allows for the most accurate strain measurement, and also to ensure that the skin deformation amount and the voltage characteristics of the resistance wire strain gauge are The linear relationship between is enhanced. Furthermore, the strain gauge side device can be manufactured and handled easily. Moreover, by setting the dimension range as described above, it is possible to measure up to 500% strain. Incidentally, it is said that the strain of the skin of a human body is approximately several hundred percent at most, and the strain measuring instrument of the present invention can almost adequately measure the deformation associated with the movement of the human body.

In addition, in the case of the strain measuring instrument according to the embodiment shown in FIG.

The number of rectangular parts can be arbitrarily changed depending on the length of the measurement location. Also, the dimensions of each rectangular part (See 1.d, See 3)
may be the same or may be different depending on the measurement location.

Further, it is preferable that the resistance wire strain gauge 2 is attached to both the upper and lower surfaces of the band l, so that only elongation or contraction can be detected, and distortion caused by bending deformation can be removed. be done.

The material of the band constituting the strain measuring instrument of the present invention is preferably a phosphor bronze plate, and the thickness of this band is 0.1-0.5.
It is preferable to set it to about mm.

[Effects] As detailed above, the strain measuring instrument of the present invention can be freely attached to the object to be measured, and can detect not only two-dimensional (two-dimensional) changes but also three-dimensional (3D) changes, which were difficult with conventional methods. This makes it possible to obtain data on three-dimensional (three-dimensional) changes easily, quickly, and inexpensively.

Furthermore, the strain measuring instrument of the present invention can be applied to dynamic strain measurement of soft and highly deformed objects such as the skin of a living body. (distortion of the skin corresponding to the position of the skin) or when the arm circumference, armpit, etc. expand and contract. Therefore, it is possible to accurately and quantitatively obtain the deformation characteristic data required when designing shoes and clothing.

It is possible to produce clothes with excellent fit and comfort.

Taking shoe last design as an example, the dimensions used in conventional last design were the dimensions of a person's foot when standing still. In contrast, according to the strain measuring device of the present invention, the dynamic deformation of any part of one foot can be measured accurately and quickly, so the deformation status of the foot metal body during one walk can be quantitatively grasped, and the It is possible to improve the accuracy of the wooden mold design, which is directly linked to function, especially fit.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a strain measuring instrument according to an embodiment of the present invention, and FIG.
3 and 4 are sectional views schematically showing the state of deformation of the strain measuring instrument according to the same embodiment. FIGS. 5 and 6 are sectional views showing the strain measuring instrument according to the embodiment. The operating characteristic diagrams of the measuring instrument, FIGS. 7 and 8 are side views showing different embodiments. l, 4, 5...Band body, 2...Resistance wire strain gauge. 3...Measurement object.

Claims (1)

[Claims] (1) A strain measuring instrument that includes a thin metal band having a wave-like shape and a resistance wire strain gauge affixed to the crest of the wave of the band.