JP2003130772A - Fracture strength measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fracture strength measuring instrument which can directly evaluate the fracture strength of a fine balloon, fiber, etc., caused by compression or bending with accuracy. SOLUTION: This fracture strength measuring instrument is provided with a loading means 2 having a transparent section 6 which causes a compressive load to act on a sample A, a load measuring means 3 which measures the load caused to act on the sample A by means of the loading means 2, and a microscope 4 under which the dimension of the sample A is measured and the fracturing process, etc., of the sample A caused by the load is observed through the transparent section 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fracture strength measuring device, and more particularly to a fracture strength measuring device that can be suitably used for evaluating the fracture strength of a fine sample such as lightweight aggregate or fine foam particles. It is about.

[0002]

2. Description of the Related Art For example, a part of pulverized coal combustion fly ash generated in a power plant is spherical glass having bubbles inside. Although academically called the cenosphere, it is called a balloon here.

The size of the balloon is 0.3.
Balloons with a specific gravity of 1.0 or less are currently used for lightweight construction materials, substrates for electronic parts, or undercoats for automobiles, sealing materials, PVC shoe soles, etc. It is used as a lightweight filler in various fields. In any case, it is mixed with cement or various synthetic resins. In this mixing step, the weak balloons are easily broken, and the broken balloons have an increased specific gravity, so that they cannot serve as the lightweight filler. Therefore, evaluating the strength of the balloon is
Very important.

Conventionally, as a method of evaluating the strength of a fine balloon, there is a method of measuring the volume reduction rate by a mercury pressurizing method. This method uses, for example, a mercury intrusion porosimeter to apply isotropic pressure to a predetermined amount of balloons to break them,
The volume reduction rate (volume reduction rate) at that time is measured, and the strength of the balloon is evaluated based on the volume reduction rate.

However, the volume reduction rate of various balloons obtained by the above-described mercury pressurizing method and the fragility (strength) of various balloons obtained from the experience of actually mixing the balloon with cement and various synthetic resins are considered. The evaluation was not always in agreement. An example is shown in Table 1.

[0006]

[Table 1]

From Table 1, empirically fragile (strength: small)
Australia's D-balloons, which are evaluated to be, do not show a large volume reduction rate compared to others, and are empirically evaluated to have the same fragility (both strength: medium). The B balloon produced in China and the C balloon produced in the UK show a large difference in the volume reduction rate.

From the above, it is difficult to accurately evaluate the fragility of the balloon in the mixing step by the conventional method of measuring the volume reduction rate of the balloon by the mercury pressurization method. I understand. This is because the method of pressurizing with mercury will apply isotropic stress to the sample, but the stress generated when the balloon is mixed with cement or synthetic resin is anisotropic such as shear stress or uniaxial compressive stress. It is presumed that this is due to the sexual stress.

Further, various fine fibers such as glass fibers, carbon fibers and mineral fibers are also mixed with cement or various synthetic resins as reinforcing fibers. Then, even these fibers are destroyed in the mixing step, and when the length becomes short, it becomes impossible to function as a reinforcing fiber, so it is important to evaluate the fracture strength, especially the bending strength. Become. However, as with the balloon above,
There is no device that can evaluate the breaking strength of fine fibers well.

Therefore, an object of the present invention is to provide a fracture strength measuring apparatus capable of directly estimating the fracture strength due to compression or bending of a balloon, a fiber or the like and observing the fracture process so that the cause of the fracture can be inferred. To provide. Note that Japanese Patent Laid-Open No. 10-142132 discloses a fracture strength test apparatus capable of observing a fracture process of a sample with a microscope similar to the present invention. This test apparatus is specified by JIS. A test device for measuring the Vickers hardness of a semiconductor element or the like, and a device for directly evaluating the fracture strength due to compression or bending of fine balloons or fibers, which is the main object of the present invention, is the measurement target. The sample and the measurement item are fundamentally different and cannot be used for the purpose of the present invention.

[0011]

In order to achieve the above object, the present invention measures a load means having a transparent portion for applying a compressive load or a bending load to a sample, and a load applied to the sample by the load means. And a microscope for observing the dimensional measurement of the sample and the rupture process of the sample due to the load through the transparent part of the load means.

According to the above-mentioned fracture strength measuring apparatus of the present invention, the dimension of the sample, which is an important factor in evaluating the fracture strength, can be accurately measured in a state of being enlarged by a microscope, and the means for loading the sample And the load measuring means for measuring the load applied to the sample by the load means, the compressive strength or bending strength of the sample can be directly and accurately measured. Further, in the conventional compression or bending strength tester, when the sample is fine or the pressure plate etc. obstructs the destruction process of the sample due to the load that cannot be seen through the transparent part provided in the loading means. Since it is possible to directly observe in a magnified state with a microscope, various information can be obtained from the fracture process of the sample, etc., for example, it becomes easy to find an abnormal value in the fracture strength measurement value of each sample and elucidate the cause thereof. It becomes possible to evaluate the breaking strength of the sample with high accuracy. From the above, it becomes possible to appropriately evaluate the strength of the lot or the particle group in the evaluation target balloon, fiber or the like.

Here, in the present invention, the load means comprises a sample mounting table on which a sample is mounted, a pressure plate disposed above the sample mounting table, and either the sample mounting table or the pressure plate. It is composed of a drive device that moves one up and down,
And, at least one of the sample mounting table or the pressure plate is constituted by a transparent plate, and the microscope is a fracture strength measuring device arranged on the side constituted by the transparent plate, and the loading means is A structure in which a pressure plate is moved up and down by the driving device, and a distance between the microscope and the sample placed on the sample mounting table is configured so that it does not change when a load is applied to the sample. In addition, it is a preferable embodiment that the above microscope is a fracture strength measuring device which is an inverted microscope.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Various embodiments of the fracture strength measuring apparatus according to the present invention described above will be described in detail below with reference to the drawings.

FIG. 1 is a side view conceptually showing a first embodiment of a fracture strength measuring apparatus according to the present invention. The fracture strength measuring apparatus 1 is a load for applying a compressive load to a sample A. Mainly composed of a means 2, a load measuring means 3 for measuring the load applied to the sample A by the load means 2, and a microscope 4 for observing the dimension measurement of the sample A and the destruction process of the sample A due to the load. ing. The sample A measured by the fracture strength measuring device according to the present invention has a particle size of 10 to 10.
1000 μm foam particles are preferable, and examples thereof include fly ash, perlite, ceramic foam particles, various balloons such as shirasu balloon, lightweight fine aggregate, and resin foam particles.

The load means 2 is a flat plate-shaped sample mounting table 5 on which the sample A is mounted, and a predetermined distance (objective lens 4) in front of the microscope (only the objective lens 4a is shown in the drawing).
The pressure plate 6 made of transparent glass fixed at a distance slightly shorter than the focal length of a) and the sample mounting table 5 are moved up and down (Z), for example, a stepping motor and rotation by the stepping motor are converted into up and down movement. And a driving device (for example, a microscope (X-Y) stage that moves up and down (Z)) 7 including a converter for moving the sample mounting table 5 upward by the driving device 7.
A compressive load is applied to the sample A between the pressure plate 6 fixed in front of the sample A.

The load measuring means 3 is a load cell constituted by a piezoelectric element such as a piezo element, which is interposed between the sample mounting table 5 which is the load means 2 and the driving device 7, and is a sample mounting device. The table 5 is configured to move upward together with the load measuring means 3 by the driving device 7 so as to measure the load applied to the sample A with the fixed pressure plate 6.

Further, the microscope 4 is arranged so that the sample A placed on the sample mounting table 5 as shown in the figure can be observed from above via the pressing plate 6 made of transparent glass which is the loading means 2. Then, the dimension measurement of the sample A placed on the sample mounting table 5 and the destruction process of the sample A due to the load applied by the load means 2 can be directly observed in an enlarged state by the microscope 4. There is.

In addition, 8 in FIG. 1 is a light source for illuminating the sample A,
Reference numeral 9 is an auxiliary mounting table placed on the sample mounting table 5, and 10 is a plate for fixing the load measuring means 3 and the like to a microscope stage (driving device 7) that vertically moves (Z).

Next, a method for measuring the breaking strength of a fine balloon using the breaking strength measuring apparatus 1 according to the present invention having the above-mentioned structure will be described below.

First, one balloon A, which is a sample to be measured, is placed on the auxiliary mount 9 while the sample mount 5 is lowered by the drive unit 7. At this time, since the auxiliary mounting table 9 is placed on the sample mounting table 5, the auxiliary mounting table 9 is a table protruding one step from the sample mounting table 5 as shown in the figure, and a plurality of balloons are attached to the auxiliary mounting table 5. When riding on 9, it is easy to leave only one on the auxiliary mounting table 9 and drop the other from the auxiliary mounting table 9.

Subsequently, the microscope stage (driving device 7) is moved in the front / rear and left / right (X-Y) directions to move the balloon A to the center of the visual field of the microscope 4, and the focus of the objective lens 4a of the microscope 4 is adjusted. , The sample mounting table 5 is moved upward by the driving device 7 (or the microscope 4 is moved downward by the driving device not shown) so as to match the shape of the balloon A with the balloon A placed on the sample mounting table 5. The size and the like are observed and measured with the microscope 4 in an enlarged state. At this time, whether or not cracks or cracks already exist in the balloon A before the pressurization observed by the microscope 4,
It is also observed whether or not the shape is a distorted shape in which dents and protrusions are present, and when the fracture strength of the balloon A is finally evaluated, the observation result is also taken into consideration.

After measuring the dimensions of the balloon A with the microscope 4, the sample mounting table 5 is further raised by the driving device 7 so that a compressive load is applied to the balloon A with the fixed pressure plate 6. The load when the balloon A breaks is measured by the load measuring means 3, and the breaking process of the balloon A is directly observed in a magnified state by the microscope 4 via the pressure plate 6 made of transparent glass. At this time, the sample mounting table 5 is gradually raised by the driving device 7, so that the distance between the balloon A and the objective lens 4a of the microscope 4 (a in the figure).
However, the focus of the objective lens 4a deviates from the balloon A, but the fixing position of the transparent glass pressure plate 6 fixed in front of the microscope 4 from the focus position of the objective lens 4a. By slightly (specifically, about the maximum radius of the sample A to be measured), the microscope 4 can be focused on the balloon A at a position where the balloon A is close to the pressure plate 6, and then Balloon A
Even if the sample table 5 moves as the sample mounting table 5 moves upward, the moving distance becomes short, and when the magnification of the objective lens 4a is 20 times (total magnification of 200 times) or less, the destruction process of the balloon A is sufficiently performed. Can be observed.

As described above, the fracture strength measuring apparatus 1 according to the present invention can accurately measure the diameter of the balloon A, which is an important factor in evaluating the fracture strength, with the microscope 4 magnified, and the balloon A Since it is provided with the load means 2 for loading and the load measuring means 3 for measuring the load applied to the balloon A by the load means 2, it is possible to directly and accurately measure the compressive strength of a fine balloon. Further, since the destruction process of the balloon A due to the load can be directly observed through the microscope 4 in an enlarged state through the pressure plate 6 made of transparent glass, various information can be obtained from the destruction process of the minute balloon A. Thus, for example, it becomes easy to find an abnormal value in the measured fracture strength of each balloon A and to elucidate the cause thereof, and it becomes possible to accurately evaluate the fracture strength of the fine balloon A. Thus, the strength of the entire balloon (lot) to be evaluated can be appropriately evaluated.

Next, a second embodiment of the breaking strength measuring device according to the present invention will be described with reference to FIG. This second
The fracture strength measuring apparatus 11 according to the embodiment of the present invention is different from the fracture strength measuring apparatus 1 according to the first embodiment in the configuration of the load means for the sample A.

That is, the load means 12 of the fracture strength measuring device 11 according to the second embodiment is a housing 14 fixed to a microscope (XY) stage 13 as shown in the drawing.
A sample mounting table 16 on which the sample A is mounted, which is provided via the load measuring means 15, a transparent glass pressing plate 17 disposed above the sample mounting table 16, and a transparent glass pressing plate 17. The pressure plate 17 is moved up and down (Z) via the connecting tool 18,
The pressure plate 17 made of transparent glass is moved downward by the drive device 19 and is applied to the sample A between the sample mount table 16 and the drive device 19 provided in the housing 14. It is designed to work.

In addition, a reference numeral 20 in FIG. 2 is a microscope (in the figure, an objective lens 20 for observing the sample A placed on the sample stage 16 through the transparent glass pressure plate 17).
21 is a light source for illuminating the sample A, 22 is an auxiliary mounting table placed on the sample mounting table 16, and 23 is a wing nut for removing the pressure plate 17 from the connector 18.

The fracture strength measuring device 11 according to the second embodiment can directly and accurately measure the compressive load of the sample A, similarly to the fracture strength measuring device 1 according to the first embodiment. In addition, the microscope 2 shows the destruction process of the sample A.
Although it can be observed directly in an enlarged state by 0,
The fracture strength measuring device 11 according to the second embodiment is
Since the pressure plate 17 made of transparent glass existing between the microscope 20 and the sample A is moved by the drive device 19, a compressive load is applied to the sample A,
Unlike the fracture strength measuring device 1 according to the first embodiment in which the sample mounting table 5 is moved, the distance between the microscope 20 and the sample A (the distance a in the figure) when a compressive load acts on the sample A. ) Does not change and the destruction process of the sample A can be observed with the microscope 20 focused on the sample A, which is a preferred embodiment. In addition, this second
In the fracture strength measuring device 11 according to the embodiment of
When the sample A is placed on the sample platform 16, the pressure plate 17 is removed from the connector 18 by removing the wing nut 23.

Next, a third embodiment of the breaking strength measuring apparatus according to the present invention will be described with reference to FIG. The fracture strength measuring device 31 according to the third embodiment differs from the fracture strength measuring devices 1 and 11 according to the first and second embodiments described above in that an inverted microscope is used.

The fracture strength measuring apparatus 31 according to the third embodiment also includes a load means 32 for applying a compressive load to the sample A and a load measuring means for measuring the load applied to the sample A by the load means 32. 33 and a microscope 34 for observing the dimensional measurement of the sample A and the destruction process of the sample A due to the load.

The load means 32 is provided in a state in which it is bridged over an opening 37 of a plate 36 fixed to a microscope (XY) stage 35, and a sample mounting table 38 made of transparent glass for mounting the sample A thereon. And the sample mounting table 3 made of the transparent glass
8, a pressure plate 39 disposed above the plate 8, and a connecting member 4 above the plate 36 for vertically moving (Z) the pressure plate 39.
And a driving device 42 fixed to an upper plate 41 supported by 0, the pressure plate 39 is moved downward by the driving device 42, and the sample mounting table 38 is moved.
And a compressive load is applied to the sample A.

The load measuring means 33 is a load cell composed of a piezoelectric element such as a piezo element interposed between the pressure plate 39 which is the load means 32 and the driving device 42. Is moved downward by the drive unit 42 together with the load measuring means 33 to measure the load applied to the sample A with the sample mounting table 38 made of transparent glass.

Further, the microscope 34 is the microscope (X
-Y) an inverted microscope arranged so as to face the opening 37 of the plate 36 fixed to the stage 35,
As shown in the drawing, the sample A placed on the sample placing table 38 can be observed from below through the sample placing stage 38 made of transparent glass. The dimension measurement of the sample A and the loading means 32 are performed. The destruction process of the sample A due to the load applied by the microscope can be directly observed with the microscope 34 in an enlarged state.

3, reference numeral 43 in FIG. 3 is a light source for illuminating the sample A, 44 is an auxiliary mounting table made of transparent glass placed on the sample mounting table 38, and 45 is for removing the upper plate 41 from the coupling tool 40. It is a wing nut.

The fracture strength measuring device 31 according to the third embodiment can directly and accurately measure the compressive load of the sample A, similarly to the fracture strength measuring device 1 according to the first embodiment. In addition, the microscope 3 shows the destruction process of the sample A.
4 can be directly observed in the enlarged state, and the second
Similarly to the fracture strength measuring apparatus 11 according to the embodiment of the present invention, the distance between the microscope 34 and the sample A (distance a in the figure) does not change when the compressive load acts on the sample A, and the microscope 34 does not change. Although it is possible to observe the destruction process of the sample A while keeping the focus of the sample A on the sample A, the fracture strength measuring device 31 according to the third embodiment uses the inverted microscope 34 as a microscope. , A drive device 42 for vertically moving (Z) the pressure plate 39, as shown in FIG.
9 and the structure thereof can be made simpler than the load means 12 of the fracture strength measuring device 11 according to the second embodiment, and the sample A can be used as a sample. When placing on the mounting table 38, by removing the wing nut 45, it is possible to remove all of the pressure plate 39 and the like above the sample mounting table 38, and it is easier to set the sample A, which is more preferable. It becomes an embodiment.

Next, a fourth embodiment of the breaking strength measuring apparatus according to the present invention will be described with reference to FIG. This 4th
The fracture strength measuring device 51 according to the first embodiment is configured so as to be able to measure the bending strength of a fine fiber or the like, and the fracture strength measuring devices 1 and 11 according to the first to third embodiments are configured. And 31, but the configuration is the same as the third
Of the breaking strength measuring device 31 according to the embodiment of the present invention, except that the bending jig 52 is provided on the sample mounting table 38 made of transparent glass and the pressure plate 39 arranged above the sample mounting table 38, respectively. Therefore, for other components,
The same reference numerals as those of the fracture strength measuring device 31 according to the third embodiment described above are given, and description thereof is omitted. Examples of the fiber A measured by this breaking strength measuring device include asbestos, wollastonite, artificial fibers and the like having a fiber diameter of 1 to 100 μm and a fiber length of 5 to 1000 μm.

According to the fracture strength measuring apparatus 51 of the fourth embodiment, the fiber A which is an important factor in evaluating the bending strength of the fine fiber A is obtained.
Since the diameter and the like of the fiber A can be accurately measured in a state of being enlarged by the microscope 34, and the load means 32 for loading the fiber A and the load measuring means 33 for measuring the load acting on the fiber A by the load means 32 are provided. It is possible to directly and accurately measure the bending strength of fine fibers. In addition, the destruction process of the fiber A due to the load,
Since it is possible to directly observe in a magnified state by the microscope 34 through the sample mounting table 38 made of transparent glass, various information such as the presence or absence of cracks can be obtained from the breaking process of the fine fiber A, and each fiber A can be obtained. It becomes easy to find the breakage part of the fiber and the abnormal value in the measured breaking load, and it becomes possible to evaluate the breaking strength of the fine fiber A with high accuracy.

In the fracture strength measuring devices 1 and 11 according to the first and second embodiments, the bending jigs are provided on the respective sample mounting tables and the pressure plates arranged above the sample mounting tables so that the fine jigs It goes without saying that a device capable of measuring the bending strength of various fibers can be used.
However, in this case, the bending jig provided on the pressure plate exists between the microscope and the sample, which may hinder the measurement of the sample size by the microscope and the observation of the sample destruction process due to the load. Therefore, like the fracture strength measuring device 51 according to the fourth embodiment, the inverted microscope 3
4, the bending jig 52 provided on the sample mounting table 38
It is a preferred embodiment that the sample A placed on the top can be observed from below.

Although various embodiments of the fracture strength measuring apparatus according to the present invention have been described above, the present invention is not limited to the above-described embodiments.

[0040]

As described above, according to the fracture strength measuring apparatus of the present invention described above, the dimension of the sample, which is an important factor in evaluating the fracture strength, can be accurately measured in a state where it is enlarged by a microscope, and Since it is provided with a load means for measuring the load applied to the sample and a load measuring means for measuring the load applied to the sample by the load means, the compressive strength or bending strength of the sample can be directly and accurately measured. Also, in the conventional compression or bending strength tester, the process of breaking the sample due to the load that could not be seen due to the pressure plate etc. obstructed by the microscope through the transparent part provided in the loading means. Since it can be directly observed, various information can be obtained from the destruction process of the sample,
For example, there is an effect that it becomes easy to find an abnormal value in the measured value and to elucidate the cause thereof, and it becomes possible to evaluate the fracture strength of the sample with high accuracy. From the above, there is an effect that it is possible to appropriately evaluate the strength of a lot or a particle group in a balloon, a fiber or the like to be evaluated.

[Brief description of drawings]

FIG. 1 is a side view conceptually showing a first embodiment of a breaking strength measuring device according to the present invention.

FIG. 2 is a side view conceptually showing a second embodiment of the fracture strength measuring device according to the present invention.

FIG. 3 is a side view conceptually showing a third embodiment of the fracture strength measuring device according to the present invention.

FIG. 4 is a side view conceptually showing a fourth embodiment of the breaking strength measuring device according to the present invention.

[Explanation of symbols]

1,11,31,51 Fracture strength measuring device 2,12,32 load means 3,15,33 Load measuring means 4,20,34 microscope 5,16,38 Sample stand 6,17,39 Pressure plate 7,19,42 drive 8,21,43 light source 9,22,44 Auxiliary mounting table 10,36,41 plate 7,13,35 Microscope (XY) stage 14 housing 18,40 connector 23,45 Wing nut 37 opening 52 Bending jig A sample a Distance between microscope and sample

Claims (4)

[Claims] 1. A loading means having a transparent portion for exerting a compressive load or a bending load on a sample, a load measuring means for measuring a load applied to the sample by the loading means, and a transparent portion of the loading means. A fracture strength measuring device comprising a microscope for observing a dimensional measurement of a sample and a fracture process of the sample due to a load. 2. The load means drives the sample mounting table on which a sample is mounted, a pressure plate disposed above the sample mounting table, and a drive for vertically moving one of the sample mounting table and the pressure plate. 2. An apparatus according to claim 1, wherein at least one of the sample mounting table and the pressure plate is formed of a transparent plate, and the microscope is arranged on the side formed by the transparent plate. Breaking strength measuring device. 3. The load means is configured to move the pressure plate up and down by the drive device, and the distance between the microscope and the sample placed on the sample mounting table is the load acting on the sample. The fracture strength measuring device according to claim 2, wherein the fracture strength measuring device is configured so as not to change from time to time. 4. The fracture strength measuring device according to claim 1, wherein the microscope is an inverted microscope.