JP3671084B2 - Simple coarse rate measuring instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a simple coarse particle ratio measuring device for measuring the coarse particle ratio of particulate materials such as sand used in a ready-mixed concrete production plant.
[0002]
[Prior art]
In general, ready-mixed concrete is manufactured by mixing cement, water, and aggregate. However, in order to manufacture high-quality ready-mixed concrete, the small aggregate enters the gap formed by the large aggregate. It is important to cover the surface of these aggregates with cement paste.
[0003]
Therefore, when producing ready-mixed concrete, it is necessary to use an aggregate in which aggregates of various particle sizes are appropriately distributed. In the standard specifications for concrete, etc., the maximum size of aggregate to be used and the standard particle size The range is defined.
[0004]
To that end, in a ready-mixed concrete manufacturing plant, a sample of aggregate is collected to determine whether the aggregate to be used regularly has an appropriate particle size distribution and sieved to measure the particle size distribution of the aggregate. The coarse particle ratio that is an index of the suitability of the particle size distribution is obtained.
[0005]
And this coarse particle ratio (FM) is the size of each sieve of 10 mm, 5 mm, 2.5 mm, 1.2 mm, 0.6 mm, 0.3 mm, 0.15 mm when taking sand as an example. It is defined as a value obtained by further adding up the remaining cumulative percentage obtained by accumulating the percentage of the amount remaining in each sieve.
[0006]
For example, when the collected sand sample is sieved and the particle size distribution as shown in FIG. 6 is obtained, the coarse particle ratio in this case is the total size of the sieve having a nominal size of 10 mm and 5 mm. Since it passed, there is no residue, and the remaining percentage is zero. And each of the sieves of 2.5 mm or less remains, the sum of the remaining cumulative percentage, and dividing it by 100,
(13 + 25 + 57 + 82 + 96) /100=2.73
The value of 2.73 is obtained, and this 2.73 is the coarse grain ratio to be obtained. In the case of sand, when the coarse particle ratio is in the range of 2.3 to 3.1, the particle size distribution is considered to be close to the standard range, and the coarse particle ratio of the sand given in the example is 2.73. This sand will have a standard particle size distribution.
[0007]
[Problems to be solved by the invention]
However, in order to determine the coarse particle ratio effective for estimating the appropriateness of the aggregate particle size distribution, it would take a considerable amount of time to calculate the aggregate samples collected as described above by sieving them with a sieve. Therefore, for example, it is quite difficult to know the tendency of the coarse grain ratio of the aggregate during operation of the ready-mixed concrete production plant.
[0008]
An object of this invention is to provide the simple coarse-grain rate measuring device which can measure the coarse-grain rate of aggregate easily and rapidly in view of said point.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention supports a predetermined position of a material contact formed by a thin rod-like body by a fulcrum, and allows the material contact to be rotated around the fulcrum. While one end is used as a material detection unit, the other end is fixed to a piezoelectric element, and when a particulate material is dropped on the material detection unit of a material contactor, the impact is converted into a voltage by the piezoelectric element. The collected voltage data are sampled at a very short cycle and collected, and the collected voltage data is classified into voltage categories that have been classified in advance according to the voltage magnitude, and the voltage data classified into each voltage category. On the other hand, a coefficient for weighting each voltage division is set in advance, and the index value is obtained for each voltage division by multiplying the coefficient by the number of voltage data classified into each voltage division. , Each voltage section Deriving an index total value from the sum of the index value of each estimated a fineness modulus of particulate material against the correlation data between fineness modulus and index total value which has been determined in advance experimentally the index overall value It is characterized by doing so.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The simple coarse particle rate measuring device of the present invention drops a predetermined amount of the particulate material whose coarse particle rate is to be measured toward the material detection part of the material contactor, and the falling particulate material is the material contactor. Collides with material detector. Since the material contactor is provided with a fulcrum at its middle part so that it can rotate, the impact caused by the collision of material particles rotates the other end part of the material contactor, and the piezoelectric element fixed to the other end part is used as an impact force. By pressing with a proportional force, a voltage proportional to the impact force is output from the piezoelectric element.
[0011]
This output voltage is sampled at a very short period to collect a large amount of voltage data when the material particles collide. The collected large number of voltage data is classified according to the magnitude of the voltage, and the number of voltage data belonging to each voltage classification is obtained. The index value for each voltage category is calculated by multiplying the number of divided voltage data by a weighting factor set in advance for each category, and the sum of the index values for each voltage category is obtained and roughly calculated. The index value for obtaining the grain ratio is used.
[0012]
Then, the coarse particle ratio is estimated from the correlation between the index value and the coarse particle ratio obtained in advance through experiments or the like and the index value.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
Reference numeral 1 in the figure denotes a sensor portion of the simplified coarse particle rate measuring instrument of the present invention, which is attached with a support shaft 3 serving as a fulcrum facing in the direction perpendicular to the longitudinal direction of the material contact 2 made of a thin rod. The end portions of the respective support shafts 3 are rotatably attached to the support frame 4 via bearings 5.
[0015]
Then, the end of the material contact 2 that protrudes from the support frame 4 is the material detection unit 6, while the side accommodated in the support frame 4 is bent slightly upward into a substantially L shape, When the tip of the material contact 2 is fixed to the pressure-sensitive surface of the piezoelectric element 7 mounted on the upper portion of the support frame 4 and the material contactor 2 rotates about the support shaft 3 as a fulcrum, the end of the material contactor 2 becomes the pressure-sensitive surface. By pressing, a voltage output is obtained from the piezoelectric element 7.
[0016]
The piezoelectric element 6 is connected to an A / D converter 8, and the A / D converter 8 is connected to a central processing unit (CPU) 9. The central processing unit 9 is connected to a keyboard 10 for inputting various data and a 7-segment module 11 which is a display device, and to a storage unit 12 for storing various data, and further to a printer for printing out various data. 13 and an RS232C interface 14 which is a communication module for transferring data to various devices.
[0017]
1, the sensor unit 1 is mounted on the lower part of the measurement container 16 having the bottom lid 15 so that the material detection unit 6 of the material contact 2 protrudes inside the measurement container 16. As shown in FIG.
[0018]
For example, when measuring the coarse grain ratio of sand used for ready-mixed concrete, first, a predetermined amount of sand adjusted to the surface dry state is put into the measurement container 16. When the bottom lid 15 is opened and the sand in the measurement container 16 is dropped, the sand flowing down at this time collides with the material detection unit 6 of the material contact 2 protruding into the measurement container 16, and passes through the material contact 2. The impact force at the time of collision is transmitted to the piezoelectric element 7, and the piezoelectric element 7 outputs a voltage output corresponding to the impact force as shown in FIG.
[0019]
This voltage output is sampled through the A / D converter 8 at a very short cycle, for example, 1 ms, and a large amount of voltage data is collected when the falling material particles collide with the material contact 2 until the sand finishes falling. And once stored in the storage unit 11.
[0020]
For example, if voltage data as shown in the A column of FIG. 5 is collected, each voltage data in the A column is classified into voltage classifications shown in the B column (in the figure, divided into 10 levels in increments of 1v). Thus, the number of voltage data for each voltage category is obtained as in column C. Then, as shown in the column D, a coefficient for weighting for each voltage classification is obtained in advance by experiments or the like so as to closely match the particle size distribution of the material to be measured. An index value for each voltage category shown in the E column is obtained by multiplying the coefficient in the D column and the number of voltage data in the C column. When the index value for each voltage category is obtained, the sum of these values is obtained and used as the index total value that correlates with the coarse grain ratio.
[0021]
In order to estimate the coarse particle ratio of the sand measured from this index total value, the sample sand is measured in advance with a simple coarse particle ratio measuring instrument to obtain the above-mentioned total index value, and the particle size is determined by actually sieving with a sieve. Correlation data between the index total value and the coarse particle ratio for various particle size distributions is obtained by a method of calculating the coarse particle ratio by obtaining the distribution, and input as initial data to a simple coarse particle ratio measuring device. And when measuring the coarse grain ratio of sand, if the index total value is obtained by a simple coarse grain ratio measuring device, the coarse grain ratio is estimated in light of the correlation data of the coarse grain ratio inputted in advance.
[0022]
Needless to say, when a plurality of sensor units are attached to a measurement container and more voltage data is detected and analyzed when the material is dropped during measurement, the measurement accuracy increases. In FIG. 5, the number of voltage data is 10 and the voltage classification is 10 levels. However, in actuality, the number of voltage data is 500 or more, and the voltage classification is further finely divided, for example, about 1000 levels. Therefore, the voltage data is processed to improve the measurement accuracy.
[0023]
【The invention's effect】
As described above, in the simple coarse particle rate measuring device according to the present invention, the material contact 2 formed by a thin rod-shaped body is rotatable about a predetermined position, and one end of the material contact 2 is made of a material. While the other end is fixed to the piezoelectric element 7 and the impact when the particulate material is dropped on the material detecting section 6 of the material contactor 2 is converted into a voltage by the piezoelectric element 7 , The converted voltage data is sampled at a very short period and collected, and the collected voltage data is classified into voltage categories that have been classified in advance according to the voltage magnitude, and the voltage classified into each voltage category. While obtaining the number of data, a coefficient for weighting each voltage division is set in advance, and the index value is calculated for each voltage division by multiplying the coefficient by the number of voltage data classified into each voltage division. The number of indicators for each voltage category Deriving an index total value from the sum. Thus estimate its coarse rate against the correlation data between fineness modulus and index total value which has been determined in advance experimentally the index overall value, easy In addition, the coarse particle ratio of the particulate material can be measured quickly.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a simple coarse particle ratio measuring device of the present invention.
FIG. 2 is a front view in which a part of a sensor portion of the simple coarse particle rate measuring device of the present invention is cut away.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a graph showing an example of voltage output.
FIG. 5 is a chart showing a processing example of voltage data.
FIG. 6 is a chart showing sand sieving data.
[Explanation of symbols]
2 ... Material contact 3 ... Support shaft (fulcrum)
6 ... Material detection part 7 ... Piezoelectric element 15 ... Bottom cover 16 ... Measurement container

Claims (1)

A predetermined position of a material contact formed by a thin rod-like body is supported by a fulcrum, the material contact is rotatable around the fulcrum, and one end of the material contact is used as a material detection unit, while the other end The part is fixed to the piezoelectric element, and the impact when the particulate material is dropped on the material detection part of the material contactor is converted into a voltage by the piezoelectric element, and the converted voltage data is sampled at a very short cycle to obtain a plurality of The collected voltage data is classified into voltage categories that have been classified in advance according to the magnitude of the voltage, and the number of voltage data classified into each voltage category is obtained. A coefficient to be weighted is set in advance, and an index value is obtained for each voltage section by multiplying the coefficient and the number of voltage data classified into each voltage section. From the sum of the index values for each voltage section, Indicator total value Come out, simplified, characterized in that so as to estimate a fineness modulus of particulate material against the correlation data between fineness modulus and index total value which has been determined in advance experimentally the index overall value Coarse grain rate measuring instrument.

Images