Particle size distribution measuring device

Abstract

To accurately measure grain sizes of granular materials and accurately calculate a grain size accumulation curve of the granular materials.SOLUTION: A placement face part 20 to which a granular material mixed with granular materials 2 having different grain sizes D is charged is constituted by an inclined placement face 38, so that each of the granular materials 2 moves along an inclination on the inclined placement face 38 as the inclined placement face 38 is vibrated by a vibration part 14. Each of the granular materials 2 can be easily dispersed along the inclined placement face 38, and can be easily separated from each other. When the grain sizes D of the granular materials 2 are calculated on the basis of image data generated by imaging the granular materials 2 that are dispersed on the inclined placement face 38, and when a grain size accumulation curve that indicates the distribution of the grain sizes D of the granular materials 2 in the granular material is calculated on the basis of the calculated grain sizes D of the granular materials 2, the granular materials 2 are not stacked or contacted with each other unlike conventional cases.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a particle size distribution measuring device. [Background technology]

[0002] Conventionally, when measuring the particle size of granular materials such as aggregates such as sand and gravel that are mixed with cement to make concrete, or embankments that are piled on land to make it level or give it a slope, and calculating a particle size accumulation curve that shows the particle size distribution, a method has been used in which the granular material is sieved using multiple sieves with different mesh sizes, and the proportion of the mass of the granular material that passed through each sieve to the total mass of the granular material is calculated. This method has the problem that it requires a lot of manual labor and time. Therefore, Patent Document 1 proposes a technique for determining the particle size of a granular material from image data generated by capturing an image of the granular material with a digital camera. Patent document 2 also proposes a technology in which a container containing granular material is vibrated to vibrate the granular material, the dispersed granular material is imaged to generate image data, the particle size of the granular material is calculated based on the image data, and a particle size accumulation curve is calculated based on the calculated particle size of the granular material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-038865 A [Patent Document 2] Patent No. 6319791 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology of Patent Document 1, there is a concern that the granular materials may overlap or come into contact with each other when imaged, which is disadvantageous in accurately calculating the particle size of the granular material from the image data of the granular material. In addition, although the technology of Patent Document 2 involves vibrating the granular material to disperse it, simply vibrating it is insufficient to reliably eliminate overlapping or contacting granular material particles, which is disadvantageous in accurately calculating the particle size of the granular material from its image data. Therefore, the above two conventional techniques have room for improvement in terms of accurately measuring the particle size of granular material and accurately calculating the particle size accumulation curve. The present invention has been devised in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a particle size distribution measuring device that is advantageous for accurately measuring the particle size of granular material and accurately calculating the particle size accumulation curve of the granular material. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention is a particle size distribution measuring device comprising a loading surface onto which a granular material containing a mixture of granular materials of different particle sizes is loaded, a vibration unit which applies vibration to the loading surface to disperse the granular material on the loading surface, an imaging unit which images the granular material dispersed on the loading surface to generate image data, an image processing unit which calculates the particle size of the granular material based on the image data, and a particle size distribution calculation unit which calculates a particle size accumulation curve showing the particle size distribution of the granular material in the granular material based on the particle size of the granular material calculated by the image processing unit, wherein the loading surface is configured as an inclined loading surface inclined with respect to a horizontal plane. In one embodiment of the present invention, the inclined placement surface is formed of a material having a large coefficient of friction with respect to the granular material. One embodiment of the present invention is characterized in that the center of the mounting surface portion is located at the highest position, the inclined mounting surface is formed in a pyramidal shape with a plurality of independent inclined mounting surfaces with different inclination angles relative to a horizontal plane arranged around the center, and the particle size distribution calculation unit calculates the particle size accumulation curve by calculating the average value of the particle size accumulation curve calculated for each of the independent inclined mounting surfaces. One embodiment of the present invention is characterized in that a plurality of divided inclined mounting surfaces having different inclination angles relative to a horizontal plane are connected from a point located at the upper end to a point located at the lower end of the inclined mounting surface or the independent inclined mounting surface, and the particle size distribution calculation unit calculates the particle size accumulation curve by calculating the average value of the particle size accumulation curve calculated for each of the divided inclined mounting surfaces. One embodiment of the present invention is characterized in that the central portion of the mounting surface portion is located at the highest position, the inclined mounting surface is formed in a pyramidal shape with a plurality of independent inclined mounting surfaces arranged around the central portion, which have the same inclination angle with respect to a horizontal plane and which have different friction coefficients with respect to the granular material, and the particle size distribution calculation unit calculates the particle size accumulation curve by calculating the average value of the particle size accumulation curve calculated for each of the independent inclined mounting surfaces. One embodiment of the present invention is characterized in that the mounting surface portion has an upwardly convex dome shape, and the inclined mounting surface is formed as a curved, inclined mounting surface facing upward of the mounting surface portion. In one embodiment of the present invention, the placement surface portion has an upwardly convex cone shape, and the inclined placement surface is formed by a conical surface forming an outer circumferential surface of the placement surface portion. One embodiment of the present invention is a particle size distribution measurement method that includes applying vibration to a loading surface onto which a granular material containing a mixture of granular materials of different particle sizes is poured, dispersing the granular material on the loading surface, capturing an image of the granular material dispersed on the loading surface with an imaging unit to generate image data, calculating the particle size of the granular material based on the image data, and calculating a particle size accumulation curve showing the particle size distribution of the granular material in the granular material based on the calculated particle size of the granular material, characterized in that while the loading surface is inclined with respect to a horizontal plane, the loading surface is vibrated to disperse the granular material on the loading surface, and then, while the loading surface is oscillated and positioned on a horizontal plane, the granular material is captured by the imaging unit with its optical axis perpendicular to the loading surface to generate the image data. Effect of the Invention

[0006] According to one embodiment of the present invention, the placement surface portion is configured as an inclined placement surface, and each of the granular materials moves along the inclination on the inclined placement surface by vibration of the inclined placement surface. Therefore, the particle size of the granular material is calculated based on image data generated by imaging the granular material dispersed on the inclined supporting surface, and a particle size accumulation curve showing the distribution of particle sizes of the granular material in the granular material is calculated based on the calculated particle sizes of the granular material, without the granular material overlapping or coming into contact with each other as in the conventional method. Therefore, the particle size of each granular material can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material, and is advantageous for efficiently and accurately evaluating granular materials. Furthermore, if the inclined supporting surface is made of a material with a large coefficient of friction against the granular material, the granular material will be able to roll more easily on the inclined supporting surface, which will cause the individual granular materials to disperse and become more easily separated from one another, which is advantageous for accurately measuring the particle size and accurately calculating the particle size accumulation curve of the granular material, and is advantageous for efficiently and accurately evaluating the granular material. In addition, if the inclined supporting surface is formed from a plurality of independent inclined supporting surfaces each having a different inclination angle, or if the inclined supporting surface is constructed by connecting a plurality of divided inclined supporting surfaces each having a different inclination angle relative to the horizontal plane, or if the inclined supporting surface is formed from a plurality of independent inclined supporting surfaces each having a different friction coefficient against the granular material, this is advantageous in promoting the dispersion of the granular material regardless of the physical properties of the granular material, and moreover, image data when the granular material is dispersed using a plurality of independent inclined supporting surfaces or a plurality of divided inclined supporting surfaces can be obtained in a single operation, which is advantageous in improving work efficiency. Therefore, the particle size of each granular material can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material, and is advantageous for efficiently and accurately evaluating the granular material. Furthermore, if the inclined supporting surface is formed as a curved supporting surface and vibration is used to cause each piece of granular material to move along the slope on the curved supporting surface, the individual pieces of granular material will be more likely to disperse along the curved supporting surface and become more likely to separate from each other. Therefore, the particle size of each granular material can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material, and is advantageous for efficiently and accurately evaluating the granular material. Furthermore, if the inclined supporting surface is constructed as a conical surface and each piece of granular material moves along the incline on the conical surface as the conical surface vibrates, the individual pieces of granular material become more likely to disperse along the curved supporting surface and become more likely to separate from each other. Therefore, the particle size of each granular material can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material, and is advantageous for efficiently and accurately evaluating the granular material. Furthermore, according to one embodiment of the present invention, with the mounting surface portion inclined relative to a horizontal plane, the mounting surface portion is vibrated to disperse the granular material onto the mounting surface portion, and then, with the mounting surface portion oscillated and positioned on a horizontal plane, the granular material is imaged by an imaging unit whose optical axis is perpendicular to the mounting surface portion, thereby generating image data. Therefore, distortion of image data of granular material can be suppressed, which is advantageous in ensuring the accuracy of the contour shape and size of the granular material in the image data, and therefore the particle size of each granular material can be measured more accurately, which is advantageous in accurately calculating the particle size accumulation curve of granular material 2, and is advantageous in efficiently and accurately evaluating granular materials. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram showing a configuration of a particle size distribution measuring device according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram showing the configuration of a control system of the particle size distribution measuring device according to the first embodiment. [Diagram 3] FIG. 2 is a perspective view showing a container of the particle size distribution measuring device according to the first embodiment. [Figure 4] (A) is a plan view of the container, and (B) is a cross-sectional view taken along line BB of (A). [Diagram 5] 3 is an operation flowchart of the particle size distribution measuring device according to the first embodiment. [Figure 6]1 is an explanatory diagram showing an example of image data of granular material dispersed on a mounting surface portion; [Figure 7] 2 is a diagram showing an example of a particle size accumulation curve calculated by the particle size distribution measuring device according to the first embodiment. FIG. [Figure 8] FIG. 11 is a plan view of a container and a mounting surface of a particle size distribution measuring device according to a second embodiment. [Figure 9] 9 is a view taken along line XX in FIG. 8, showing horizontal position P1 of the placement surface portion. [Figure 10] 9 is a view taken along line XX in FIG. 8, showing an inclination position P2 of the placement surface portion. [Figure 11] 13 is a partial enlarged view of an upper fixing portion provided on an upper portion of the guide member. FIG. [Figure 12] 10A is a plan view of a container of a particle size distribution measuring device according to a third embodiment, FIG. 10B is an enlarged cross-sectional view taken along line BB in FIG. 10A, and FIG. 10C is an enlarged cross-sectional view taken along line CC in FIG. [Figure 13] 13A is a plan view of a container of a particle size distribution measuring device according to a fourth embodiment, FIG. 13B is an enlarged cross-sectional view taken along line BB in FIG. 13A, and FIG. 13C is an enlarged cross-sectional view taken along line CC in FIG. [Figure 14] 13A is a plan view of a container of a particle size distribution measuring device according to a fifth embodiment, FIG. 13B is an enlarged cross-sectional view taken along line BB in FIG. 13A, and FIG. 13C is an enlarged cross-sectional view taken along line CC in FIG. [Figure 15] 13 is an operation flowchart of a particle size distribution measuring device according to a fifth embodiment. [Figure 16] 13(A) is a plan view of a container of a particle size distribution measuring device of the sixth embodiment, (B) is an enlarged cross-sectional view along line BB of (A), (C) is an enlarged cross-sectional view along line BB of (A) in a first modified example, and (D) is an enlarged cross-sectional view along line BB of (A) in a second modified example. [Figure 17] 13 is an operation flowchart of a particle size distribution measuring device according to a sixth embodiment. [Figure 18] 13A is a plan view of a container of a particle size distribution measuring device according to a seventh embodiment, FIG. 13B is an enlarged cross-sectional view taken along line BB in FIG. 13A, and FIG. 13C is an enlarged cross-sectional view taken along line CC in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (First embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the terms used in this specification will be explained. Granular materials are materials used, for example, in civil engineering and construction work, and specifically include aggregates such as sand and gravel that are mixed with cement to make concrete, and embankment materials that are piled up on land to make it flat or give it a slope. Aggregates and fill materials are composed of granular materials that are a mixture of granular materials of different particle sizes. The particle size of a granular material is the area defined by the contour of the granular material when it is projected onto a plane, in other words, the area equivalent diameter calculated as the diameter of a circle when the area defined by the contour of the granular material identified on image data captured by an imaging device is taken as the area of ​​the circle. The reason for calculating the area equivalent diameter as the particle diameter of the granular material is that the granular material is not circular but has various irregular shapes. Granular materials that make up aggregates and embankments are classified as follows according to the range of particle size D (JISA0207:2018 (Geotechnical Engineering Terminology)). Clay content: Particle size D<0.005mm Silt content: 0.005mm≦particle size D<0.075mm Sand content: 0.075mm≦Particle size D<2mm Gravel: 2mm≦grain size D<75mm Stone content: 75mm≦particle size D

[0009] The particle size accumulation curve indicates the distribution of particle sizes of the granular materials that make up the granular material. As shown in Figure 7, the particle size accumulation curves C1 and C2 are represented by a semi-logarithmic graph with the particle size D of each granular material on the horizontal axis (logarithmic scale) and the passing mass percentage P (also called the accumulated passing rate) on the vertical axis (linear scale). The passing mass percentage P is the mass percentage of granular material having a particle size D or less relative to the total, that is, the percentage of the total mass of granular material having a particle size D or less relative to the total mass of all granular material.

[0010] Next, the configuration of the particle size distribution measuring device 10 according to the present embodiment will be described. As shown in FIGS. 1 and 2, the particle size distribution measuring device 10 includes a container 12A, a vibration section 14, an imaging section 16, and a computer 18. As shown in Figure 3, container 12A is used to pour granular material containing a mixture of granular materials of different particle sizes, and is formed with an open upper portion and has a mounting surface 20 and a side wall 22 that rises from the periphery of mounting surface 20. In this embodiment, the placement surface portion 20 has a rectangular plate shape having long sides and short sides, but the shape of the placement surface portion 20 is not limited and may be a circle, a polygon, or the like. The placement surface 20 is where the granular material is poured. FIG. 4A is a plan view showing a schematic diagram of the placement surface portion 20, and FIG. 4B is a cross-sectional view taken along line BB in FIG. The support surface portion 20 is configured with an inclined support surface 38 that is inclined with respect to the horizontal plane. In this embodiment, the inclined support surface 38 is composed of a plane inclined at a predetermined angle with respect to the horizontal plane, and the inclined support surface 38 is highest at one end in the longitudinal direction and lowest at the other end in the longitudinal direction, with the height decreasing from one end in the longitudinal direction to the other end.

[0011] Since the mounting surface portion 20 is composed of an inclined mounting surface 38, when the granular material is added to the mounting surface portion 20 and the inclined mounting surface 38 is vibrated by the vibration portion 14, each of the granular pieces 2 that make up the granular material moves from top to bottom along the inclined mounting surface 38, and is dispersed along the inclined mounting surface 38.

[0012] In addition, the container 12A including the mounting surface portion 20 can be constructed from conventionally known materials such as metal or synthetic resin, but if the inclined mounting surface 38 is formed from a material with a high coefficient of friction with respect to the granular material 2, the vibration of the inclined mounting surface 38 will cause the granular material 2 to roll easily. Therefore, each of the granular materials 2 that overlap or contact each other becomes easier to separate. As a material having a large coefficient of friction with respect to the granular material, various conventionally known materials such as rubber can be used.

[0013] As shown in FIG. 1, the vibration section 14 applies vibrations to the placement surface section 20 to disperse the granular material on the inclined placement surface 38 . In this case, the vibration direction is along a horizontal plane and / or in a vertical direction. In this embodiment, a shaker 14A is used as the vibration unit 14, which shakes (shakes) a container 12A such as a test tube or an Erlenmeyer flask to mix and separate the sample therein. The shaker 14A includes, for example, a main body 1402 placed on the base 26, and a vibration table 1404 supported on the upper part of the main body 1402 so as to be capable of swinging. The vibration table 1404 is vibrated in at least one of the horizontal and vertical directions by an actuator (not shown) built into the main body 1402 . In this embodiment, the container 12A is mounted on the vibration table 1404 and attached to the vibration table 1404 by a mounting fixture (not shown). The shaker 14A is configured so that parameters such as the vibration direction, vibration amplitude, vibration frequency, and vibration time of the vibration table 1404 can be changed and set by manually operating the operation unit 1406 provided on the main body 1402. The vibration section 14 may have any configuration, and may be configured such that the inclined placement surface 38 is vibrated by applying vibration from a conventionally known vibrator device to the container 12A supported so as to be capable of vibrating.

[0014] The imaging section 16 is constituted by an imaging device 16A such as a digital camera, and captures an image of the granular material dispersed on the inclined placement surface 38 to generate image data (still image). The imaging unit 16 is supported at a location spaced above the inclined placement surface 38 via a stand 28 arranged on a base 26, and is configured to be able to image the entire area of ​​the inclined placement surface 38 from above. Although Figure 1 shows a case where the inclined mounting surface 38 is imaged by the imaging device 16A with the container 12A placed on the shaker 14A, it goes without saying that the inclined mounting surface 38 may also be imaged by the imaging device 16A with the container 12A removed from the shaker 14A and placed on the base 26.

[0015] The computer 18 includes an input device 30, an output device 32, and an external storage device 34 in addition to a CPU, a ROM, a RAM, a hard disk drive, and an input / output interface, all of which are not shown. The ROM stores predetermined control programs and the like, while the RAM provides a working area. The hard disk device stores control programs for implementing an input unit 18A, an image processing unit 18B, a particle size distribution calculation unit 18C, an output unit 18D, and a communication unit 18E, which will be described later. The input / output interface provides an interface with the following input device 30, output device 32, and network 36. The input device 30 receives operational input from an operator, and includes a keyboard 3002 and a mouse 3004 . The output device 32 outputs information, and includes a display 3202 and a printer 3204 . The external storage device 34 stores information, and includes an external hard disk device, an external SSD (solid state drive device), a semiconductor recording medium such as a memory card or a USB memory, or an optical disk recording medium such as a DVD.

[0016] The CPU executes a control program for the hard disk device, thereby realizing an input unit 18A, an image processing unit 18B, a particle size distribution calculation unit 18C, an output unit 18D, and a communication unit 18E. The input unit 18A receives image data captured by the imaging device 16A. The image processing unit 18B calculates the particle diameter D of the granular material based on the image data, calculates the area of ​​the granular material from the image data by image recognition, and calculates the particle diameter D (area equivalent diameter) from the calculated area.

[0017] The particle size distribution calculation section 18C calculates particle size accumulation curves C1 and C2 in FIG. 7 which show the distribution of particle sizes D of the granular material in the granular material based on the particle sizes D of the granular material calculated by the image processing section 18B. The output section 18D supplies data of the particle size accumulation curve calculated by the particle size distribution calculation section 18C to the output device 32 or the external storage device . The communication unit 18E communicates with a terminal (computer) not shown via a network 36 including the Internet or a dedicated line, and in this embodiment, transmits data of the particle size accumulation curve calculated by the particle size distribution calculation unit 18C to a terminal not shown.

[0018] Next, the operation of the particle size distribution measuring device 10 according to the present embodiment will be described with reference to the flowchart of FIG. First, a granular material, such as aggregate or fill material, whose particle size distribution is to be measured, is sampled (step S10). Next, the collected granular material is placed on the placement surface portion 20 (inclined placement surface 38) of the container 12A (step S12). It is assumed that the container 12A is attached in advance to the vibration table 1404 of the shaker 14A. Then, parameters such as the vibration direction, amplitude, frequency, and vibration time of the shaker 14A are appropriately set, and the shaker 14A starts vibrating the inclined placement surface 38 (step S14). Due to the vibration of the inclined supporting surface 38, the granular material placed on the inclined supporting surface 38 is dispersed across the inclined supporting surface 38, and as it moves along the slope of the inclined supporting surface 38, each of the granular materials that make up the granular material is separated and dispersed. That is, the individual granular materials are held on the inclined support surface 38 at a distance from each other without overlapping or touching each other.

[0019] When a predetermined vibration time has elapsed and the vibration by the shaker 14A has stopped, the imaging device 16A captures an image of the entire mounting surface portion 20 (inclined mounting surface 38) to obtain image data (step S16). FIG. 6 shows an example of image data, in which each granular material 2 is depicted by a contour line. As shown in FIG. 6, the individual granular materials 2 are spaced apart from one another without overlapping or touching one another.

[0020] Next, the image processing unit 18B identifies the contours of each granular material 2 from the captured image data by image processing, calculates the area, and then calculates the area equivalent diameter of each granular material 2 as the particle size D (step S18). Then, the particle size distribution calculation unit 18C accumulates the number of granular materials 2 for each particle size D (step S20) and determines whether the accumulation has been completed for the entire number of granular materials 2 contained in the captured image data (step S22).If the determination result is negative, the process returns to step S20 and continues the accumulation, and if the determination result is positive, the process proceeds to step S24. The particle size distribution calculation unit 18C calculates the particle size accumulation curve shown in FIG. 7 based on the accumulation result of the number of granular materials 2 for each particle size D (step S24). The output unit 18D outputs the calculated particle size accumulation curve to the display 3202 to display it on the screen, or prints it out from the printer 3204. Alternatively, the output unit 18D supplies the calculated particle size accumulation curve to the external storage device 34 (step S26). Moreover, the output unit 18D transmits the calculated particle size accumulation curve from the communication unit 18E to another terminal via the network 36 (step S28). This completes the series of operations.

[0021] The calculated particle size accumulation curve is used to estimate the particle size of the granular material. FIG. 7 illustrates a particle size accumulation curve C1 with a gentle slope and a particle size accumulation curve C2 with a steep slope. Generally, the more gentle the slope of the particle size accumulation curve, the wider the range of particle size D of granular materials 2 contained, making the gaps between the granular materials 2 smaller and resulting in a stable state, and therefore the particle size of the granular material is evaluated as higher. Conversely, the steeper the slope of the particle size accumulation curve, the more granular material 2 with uniform particle size D is contained, which results in larger gaps between the granular materials 2 and an unstable state, resulting in a lower evaluation of the particle size of the granular material.

[0022] As described above, according to this embodiment, the loading surface section 20 onto which the granular material mixed with granular materials 2 of different particle sizes D is fed is composed of an inclined loading surface 38, and each of the granular materials 2 moves along the slope on the inclined loading surface 38 due to the vibration of the inclined loading surface 38 by the vibration section 14. Therefore, compared to when the supporting surface portion 20 extends along a horizontal plane, overlapping or contacting granular materials 2 are more likely to move along the inclined supporting surface 38 due to vibration, and therefore each granular material 2 is more likely to disperse along the inclined supporting surface 38 and move away from one another. Therefore, when the particle size D of the granular material 2 is calculated based on image data generated by imaging the granular material 2 dispersed on the inclined supporting surface 38, and a particle size accumulation curve showing the distribution of the particle size D of the granular material 2 in the granular material is calculated based on the calculated particle size D of the granular material 2, the granular materials 2 do not overlap or come into contact with each other as in the conventional method. Therefore, the particle size D of each granular material 2 can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating granular materials.

[0023] Furthermore, if the inclined mounting surface 38 is made of a material with a large coefficient of friction against the granular material 2, the vibration of the inclined mounting surface 38 makes it easier for the granular material 2 to roll on the inclined mounting surface 38, which makes it easier for the individual pieces of granular material 2 that are overlapping or in contact with each other to separate, and the individual pieces of granular material 2 become dispersed and separated from each other. This is advantageous in spacing the individual granular materials 2 apart from one another, in accurately measuring the particle size D, and in accurately calculating the particle size accumulation curve of the granular materials 2, and is advantageous in efficiently and accurately evaluating the granular material.

[0024] (Second embodiment) Next, a second embodiment will be described with reference to FIGS. In the following embodiment, the same parts and members as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the differences. In the first embodiment, as shown in FIG. 1, the optical axis La of the imaging device 16A is perpendicular to the horizontal plane, and therefore the optical axis La is inclined with respect to the inclined placement surface . Therefore, since the difference in distance to the imaging device 16A becomes large between the higher and lower points of the inclined supporting surface 38, there is a concern that the image data of the granular material 2 will be slightly distorted compared to when the optical axis La of the imaging device 16A is perpendicular to the inclined supporting surface 38, and that the accuracy of the contour shape and size of the granular material 2 in the image data will be reduced. Therefore, in the second embodiment, as shown in FIG. 9, the imaging device 16A is adapted to capture an image in a state in which the optical axis La of the imaging device 16A is perpendicular to the inclined placement surface .

[0025] As shown in FIGS. 8, 9, and 10, in the second embodiment, a container 12B and a mounting surface portion 20 are configured independently. The container 12B includes a rectangular bottom wall 21 having long and short sides, and a side wall 22 standing upright from the periphery of the bottom wall 21. The container 12B is attached on the vibration table 1404 of the shaker 14A (see FIG. 1), as in the first embodiment. The bottom wall 21 is constructed to have a uniform thickness, and extends on a horizontal plane when the container 12B is attached on the vibration table 1404 of the shaker 14A.

[0026] A mounting plate 40 is supported on the bottom wall 21 . The mounting plate 40 has a rectangular plate shape with an outline smaller than the outline of the container 12B, and the surface of the mounting plate 40 constitutes the mounting surface portion 20, which is formed as a flat surface. The mounting plate 40 has a support shaft 4002 protruding outward from one of a pair of long sides near the short side. The support shafts 4002 are supported by the bottom wall 21 via bearings 4004 , and the mounting plate 40 is supported so as to be swingable around the support shafts 4002 . A guide shaft 4006 is provided to protrude outward from each of the pair of long sides of the mounting plate 40 at a position near the other short side. The guide shafts 4006 are slidably guided in arc-shaped guide grooves 4010 provided in a pair of guide members 4008 standing on the bottom wall 21 . As shown in FIG. 9, with the support shaft 4002 in contact with the lower end of the guide groove 4010, the placement surface portion 20 is located at a horizontal position P1 extending on a horizontal plane. 10, the placement surface portion 20 is swung around the support shaft 4002, and with the support shaft 4002 in contact with the upper end of the guide shaft 4006, the placement surface portion 20 is positioned at an inclined position P2 inclined relative to the horizontal plane. Therefore, an inclined mounting surface 38 is formed by the mounting surface portion 20 positioned at the inclined position P2.

[0027] As shown in FIG. 11, an upper fixing portion 42 is provided on the upper portion of the guide member 4008, which fixes the vertical position of the placement surface portion 20 in the inclined position P2. The upper fixing portion 42 includes a female thread portion 4202 formed in the guide member 4008 and opening into the guide groove 4010 , and a cap screw 4204 that screws into the female thread portion 4202 . Then, by pressing the peripheral surface of the guide shaft 4006 positioned at the inclined position P2 with the tip of a cap screw 4204 screwed into the female thread portion 4202, the guide shaft 4006 is fixed so that it cannot move in the vertical direction, and the supporting surface portion 20 is fixed at the inclined position P2. As shown in FIG. 9, a lower fixing portion 44 is provided at the lower portion of the guide member 4008, which fixes the vertical position of the placement surface portion 20 at the horizontal position P1. The lower fixing portion 44 includes a female thread portion 4402 formed in the guide member 4008 and opening into the guide groove 4010 , and a cap screw 4404 that screws into the female thread portion 4402 . Then, by pressing the peripheral surface of the guide shaft 4006 positioned at the horizontal position P1 with the tip of a cap screw 4404 screwed into the female threaded portion 4402, the guide shaft 4006 is fixed so as not to be able to move in the vertical direction, and the support surface portion 20 is fixed at the horizontal position P1. It should be noted that the cap screw 4204 of the upper fixing portion 42 is omitted in FIG. 9, and the cap screw 4004 of the lower fixing portion 40 is omitted in FIG.

[0028] Next, the effects will be described. In the second embodiment, as shown in Figure 10, the mounting surface portion 20 is fixed at an inclined position P2, i.e., the mounting surface portion 20 is inclined relative to the horizontal plane to form an inclined mounting surface 38, and the inclined mounting surface 38 is vibrated by a shaker 14A to disperse the granular material 2 onto the inclined mounting surface 38. Then, as shown in Figure 9, the mounting surface portion 20 is oscillated and fixed at the horizontal position P1, and image data is generated by imaging the granular material 2 with the imaging device 16A while its optical axis La is perpendicular to the mounting surface portion 20. Then, similarly to the first embodiment, a particle size distribution calculation unit 18C calculates a particle size accumulation curve from the image data and outputs the particle size accumulation curve.

[0029] According to this second embodiment, not only can the same effects as the first embodiment be achieved, but image data can be acquired with the optical axis La of the imaging device 16A perpendicular to the inclined mounting surface 38, so distortion of the image data in which the granular material 2 is captured can be suppressed, which is advantageous in ensuring accuracy of the contour shape and size of the granular material 2 in the image data. Therefore, the particle size D of each granular material 2 can be measured more accurately, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating the granular material.

[0030] (Third embodiment) Next, a third embodiment will be described with reference to FIG. The third embodiment differs from the first and second embodiments in that the mounting surface portion 20 of the container 12C has an upwardly convex dome shape. As shown in Figure 12(A), the mounting surface portion 20 has a rectangular shape when viewed in a plane, and as shown in Figures 12(B) and (C), the inclined mounting surface 38 is formed by a curved mounting surface 46 facing upward from the mounting surface portion 20. In this embodiment, the curved mounting surface 46 is highest at its center and decreases in height as it moves away from the center. The curved mounting surface 46 may be a spherical surface formed with a constant radius of curvature, or may be a curved surface with a continuously changing radius of curvature. The curved support surface 46 may also be configured by combining a spherical surface and a curved surface.

[0031] According to the third embodiment, the inclined supporting surface 38 onto which the granular material mixed with granular materials 2 of different particle sizes D is fed is formed by a curved supporting surface 46, and each of the granular materials 2 moves along the slope on the curved supporting surface 46 due to the vibration of the curved supporting surface 46 by the vibration unit 14. Therefore, compared to when the mounting surface portion 20 extends along a horizontal plane, overlapping or contacting granular materials 2 are more likely to move along the curved mounting surface 46 due to vibration, and therefore each granular material 2 is more likely to disperse along the curved mounting surface 46 and move away from one another. Therefore, when the particle size D of the granular material 2 is calculated based on image data generated by imaging the granular material 2 dispersed on the curved supporting surface 46, and a particle size accumulation curve showing the distribution of the particle sizes D of the granular material 2 in the granular material is calculated based on the calculated particle sizes D of the granular material 2, the granular materials 2 do not overlap or come into contact with each other as in the conventional method. Therefore, the particle size D of each granular material 2 can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating granular materials.

[0032] Furthermore, if the curved mounting surface 46 is formed from a material with a large coefficient of friction against the granular material 2, the vibration of the curved mounting surface 46 makes it easier for the granular material 2 to roll on the curved mounting surface 46, which makes it easier for each piece of granular material 2 that overlaps or touches each other to separate, and each piece of granular material 2 to disperse and move away from one another. Therefore, it is advantageous for spacing each granular material 2 from each other, for accurately measuring the particle size D and for accurately calculating the particle size accumulation curve of the granular material 2, and for efficiently and accurately evaluating the granular material.

[0033] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIG. The fourth embodiment differs from the first to third embodiments in that the mounting surface 20 of the container 12D has an upwardly convex cone shape. As shown in FIG. 13(A), the mounting surface portion 20 has a circular shape in a plan view, and as shown in FIG. 13(B), the inclined mounting surface 38 is formed by a conical surface 48 that forms the outer circumferential surface of the mounting surface portion 20.

[0034] According to the fourth embodiment, the inclined loading surface 38 onto which the granular material mixed with granular materials 2 of different particle sizes D is fed is formed of a conical surface 48, and each of the granular materials 2 moves along the incline on the conical surface 48 due to the vibration of the conical surface 48 by the vibration section 14. Therefore, compared to when the supporting surface portion 20 extends along a horizontal plane, overlapping or contacting granular materials 2 are more likely to move along the conical surface 48 due to vibration, and therefore each granular material 2 is more likely to disperse along the conical surface 48 and move away from one another. Therefore, when the particle size D of the granular material 2 is calculated based on image data generated by imaging the granular material 2 dispersed on the conical surface 48, and a particle size accumulation curve showing the distribution of the particle sizes D of the granular material 2 in the granular material is calculated based on the calculated particle sizes D of the granular material 2, the granular materials 2 do not overlap or come into contact with each other as in the conventional method. Therefore, the particle size D of each granular material 2 can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating granular materials.

[0035] Furthermore, by forming the conical surface 48 from a material with a large coefficient of friction against the granular material 2, it is advantageous for separating each of the granular materials 2 from each other, which is advantageous for accurately measuring the particle size D and accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating the granular material, as in the third embodiment.

[0036] (Fifth embodiment) Next, a fifth embodiment will be described with reference to FIG. The fifth embodiment differs from the first to fourth embodiments in that the mounting surface portion 20 of the container 12E is composed of a plurality of independent inclined mounting surfaces 50. As shown in FIGS. 14(A), (B) and (C), the placement surface portion 20 has a rectangular shape in a plan view, with the center portion being located at the highest position. The inclined support surface 38 is formed in a pyramidal shape with a plurality of independent inclined support surfaces 50 arranged around the center and having different inclination angles φ with respect to the horizontal plane. In this embodiment, the inclined mounting surface 38 is formed in a quadrangular pyramid shape by four independent inclined mounting surfaces 50, namely, first, second, third and fourth independent inclined mounting surfaces 50A, 50B, 50C and 50D. In addition, when viewed in a plane, the four independent inclined support surfaces 50A, 50B, 50C, and 50D are arranged clockwise in that order, and are configured so that the inclination angle φ relative to the horizontal plane increases in that order. Further, the lower ends of the remaining three independent inclined mounting surfaces 50B, 50C, and 50D other than the first independent inclined mounting surface 50A and the lower end of the side wall 22 are connected by a plane 52 extending horizontally. It should be noted that the combinations of the first, second, third and fourth independent inclined mounting surfaces 50A, 50B, 50C and 50D and the inclination angles φ of the independent inclined mounting surfaces 50 are not limited to those described above.

[0037] Next, the operation of the particle size distribution measuring device 10 according to the fifth embodiment will be described with reference to the flowchart of FIG. First, a granular material, such as aggregate or fill material, whose particle size distribution is to be measured, is sampled (step S100). Next, the collected granular material is placed on the placement surface 20 of the container 12E (step S102). In this embodiment, the granular material is placed in the center of the inclined placement surface 38 and around its periphery. Then, parameters such as the vibration direction, amplitude, frequency, and vibration time of the shaker 14A are appropriately set, and the shaker 14A starts vibrating the inclined placement surface 38 (step S104). Due to the vibration of the inclined supporting surface 38, the granular material placed on the inclined supporting surface 38 is dispersed onto each of the four independent inclined supporting surfaces 50, and as each of the granular materials 2 that make up the granular material moves along the slope of each of the four independent inclined supporting surfaces 50, each of the granular materials 2 becomes separated and dispersed. That is, the granular materials 2 are held on the four independent inclined placement surfaces 50 at a distance from each other without overlapping or contacting each other.

[0038] When a predetermined vibration time has elapsed and the vibration by the shaker 14A has stopped, the imaging device 16A16A captures an image of the entire mounting surface 20 to obtain image data (step S106). That is, image data capturing an image of the entire area of ​​the four independent inclined placement surfaces 50 is acquired.

[0039] Next, the image processing unit 18B identifies the contours of each granular material 2 from the captured image data by image processing, calculates the area, and then calculates the area equivalent diameter of each granular material 2 as the particle size D (step S108). Next, the particle size distribution calculation unit 18C selects a first independent inclined supporting surface 50A from the four independent inclined supporting surfaces 50 (step S110), accumulates the number of granular materials 2 for each particle size D corresponding to the first independent inclined supporting surface 50A (step S112), and determines whether the accumulation has been completed for the entire number of granular materials 2 contained in the captured image data (step S114).If the determination result is negative, the process returns to step S112 and continues the accumulation, and if the determination result is positive, the process proceeds to step S116. The particle size distribution calculation unit 18C calculates the particle size accumulation curve shown in FIG. 7 based on the accumulation result of the number of granular materials 2 for each particle size D (step S116).

[0040] The particle size distribution calculation unit 18C determines whether or not the particle size accumulation curves have been calculated for all independent inclined support surfaces 50 (step S118), and if the result of this determination is negative, it selects the next independent inclined support surface 50 (step S122) and returns to step S112 to perform the same processing. If the determination result in step S118 is positive, the average value of the particle size accumulation curves corresponding to all the independent inclined mounting surfaces 50 is calculated (step S120). Then, the output unit 18D outputs the calculated particle size accumulation curve to the display 3202 to display it on the screen, or prints it out from the printer 3204. Alternatively, the output unit 18D supplies the calculated particle size accumulation curve to the external storage device 34 (step S124). Moreover, the output unit 18D transmits the calculated particle size accumulation curve from the communication unit 18E to another terminal via the network 36 (step S126). This completes the series of operations.

[0041] Here, the granular material is constituted by a mixture of granular materials 2 having different physical properties such as particle size, shape, and specific gravity. Therefore, it is considered that the ease of dispersion of the granular materials 2 when moving on the inclined placement surface 38 is affected by the difference in the physical properties of each granular material 2. Additionally, the ease of dispersion of the granular material 2 when moving on the inclined placement surface 38 is also considered to be affected by the combination of the physical properties of each granular material 2 and the inclination angle φ of the inclined placement surface 38 . According to the fifth embodiment, the inclined placement surface 38 onto which the granular material 2 is introduced is formed of a plurality of independent inclined placement surfaces 50 each having a different inclination angle φ. In this case, since the inclination angle φ of each independent inclined placement surface 50 is different, the conditions under which the granular material 2 rolls and moves are different for each independent inclined placement surface 50 . Therefore, since the granular material 2 can be dispersed using independent inclined supporting surfaces 50 having different inclination angles φ, it is advantageous in promoting the dispersion of the granular material 2 regardless of the physical properties of the granular material 2, and further, since image data when the granular material 2 is dispersed using multiple independent inclined supporting surfaces 50 can be obtained in a single operation, it is advantageous in improving work efficiency. Therefore, the particle size D of each granular material 2 can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating the granular material.

[0042] (Sixth embodiment) Next, a sixth embodiment will be described with reference to FIG. The sixth embodiment differs from the first to fifth embodiments in that the mounting surface portion 20 of the container 12F is composed of a plurality of divided inclined mounting surfaces . As shown in FIGS. 15(A) and 15(B), the placement surface portion 20 has a rectangular shape in a plan view. A plurality of divided inclined mounting surfaces 54 having different inclination angles φ with respect to the horizontal plane are connected from a location located at the upper end to a location located at the lower end of the inclined mounting surface 38 . In this embodiment, first, second, and third divided inclined support surfaces 54, each having a different inclination angle φ relative to the horizontal plane, are connected together, and are arranged in the order of the first, second, and third divided inclined support surfaces 54A, 54B, and 54C from the upper end to the lower end of the inclined support surface 38. In addition, when the inclination angles φ of the first, second, and third divided inclined placement surfaces 54A, 54B, and 54C are the first inclination angle φ1, the second inclination angle φ2, and the third inclination angle φ3, In the example shown in FIG. 15(B), φ1<φ2<φ3. In the example shown in FIG. 15(C), φ3<φ2<φ1. In the example shown in FIG. 15(D), φ1=φ3, φ1<φ2, and φ3<φ2. It should be noted that the combinations of the first, second, and third divided inclined placement surfaces 54A, 54B, and 54C and the first inclination angle φ1, the second inclination angle φ2, and the third inclination angle φ3 are not limited to those described above.

[0043] Next, the operation of the particle size distribution measuring device 10 according to the sixth embodiment will be described with reference to the flowchart of FIG. First, a granular material to be subjected to particle size distribution measurement is collected, and the collected granular material is placed on the mounting surface 20 of the container 12 (steps S200, S202). In this embodiment, the granular material is placed on the first divided inclined placement surface 54A, which is located at the highest position. Then, parameters such as the vibration direction, amplitude, frequency, and vibration time of the shaker 14A are appropriately set, and the shaker 14A starts vibrating the inclined placement surface 38 (step S204). As the inclined supporting surface 38 vibrates, the granular material placed on the inclined supporting surface 38 moves along the slope of the first, second and third divided inclined supporting surfaces 54A, 54B and 54C in that order, so that each granular piece 2 constituting the granular material becomes separated and dispersed on the first, second and third divided inclined supporting surfaces 54A, 54B and 54C, respectively. That is, the granular materials 2 are held on the three divided inclined placement surfaces 54 at a distance from each other without overlapping or contacting each other.

[0044] When a predetermined vibration time has elapsed and the vibration by the shaker 14A has stopped, the imaging device 16A16A captures an image of the entire mounting surface 20 to obtain image data (step S206). That is, image data capturing an image of the entire area of ​​the three divided inclined placement surfaces 54 is obtained.

[0045] Next, the image processing unit 18B identifies the contours of each granular material 2 from the captured image data by image processing, calculates the area, and then calculates the area equivalent diameter of each granular material 2 as the particle size D (step S208). Next, the particle size distribution calculation unit 18C selects the first divided inclined supporting surface 54A from the three divided inclined supporting surfaces 54 (step S210), adds up the number of granular materials 2 for each particle size D corresponding to the first divided inclined supporting surface 54 (step S212), determines whether the addition has been completed for the entire number of granular materials 2 contained in the captured image data (step S214), and if the determination result is negative, selects the next divided inclined supporting surface 54 (step S222), returns to step S212, selects the next divided inclined supporting surface 54 and performs the addition, and if the determination result of step S214 is positive, proceeds to step S216. The particle size distribution calculation unit 18C calculates the particle size accumulation curve shown in FIG. 7 based on the accumulation result of the number of granular materials 2 for each particle size D (step S216).

[0046] The particle size distribution calculation unit 18C determines whether or not the particle size accumulation curves have been calculated for all divided inclined supporting surfaces 54 (step S218), and if the result of this determination is negative, it selects the next divided inclined supporting surface 54 (step S222) and returns to step S212 to perform the same processing. If the determination result in step S218 is positive, the average value of the particle size accumulation curves corresponding to all the divided inclined mounting surfaces 54 is calculated (step S220). Then, output unit 18D outputs the calculated particle size accumulation curve, and transmits the calculated particle size accumulation curve from communication unit 18E to another terminal via network 36 (steps S224, S226). This completes the series of operations.

[0047] As described above, according to the sixth embodiment, the inclined placement surface 38 onto which the granular material 2 is loaded is configured by connecting a plurality of divided inclined placement surfaces 54 having different inclination angles φ with respect to the horizontal plane. At this time, since the inclination angle φ of each divided inclined placement surface 54 is different, the conditions under which the granular material 2 rolls and moves for each divided inclined placement surface 54 are different. Therefore, since the granular material 2 can be dispersed using divided inclined supporting surfaces 54 having different inclination angles φ, it is advantageous in promoting the dispersion of the granular material 2 regardless of the physical properties of the granular material 2, and further, since image data when the granular material 2 is dispersed using multiple divided inclined supporting surfaces 54 can be obtained in a single operation, it is advantageous in improving work efficiency. Therefore, the particle size D of each granular material 2 can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating the granular material. It should be noted that the sixth embodiment can also be applied to the fifth embodiment. In this case, a plurality of divided inclined support surfaces 54 having different inclination angles φ relative to the horizontal plane are connected from the upper end to the lower end of the independent inclined support surface 50, thereby further enhancing the effect of the fifth embodiment.

[0048] (Seventh embodiment) Next, a seventh embodiment will be described with reference to FIG. The seventh embodiment differs from the first to sixth embodiments in that the support surface portion 20 of the container 12G is composed of a plurality of independent inclined support surfaces 56, and the plurality of independent inclined support surfaces 56 have mutually different coefficients of friction with respect to the granular material 2. As shown in FIGS. 18(A), (B) and (C), the placement surface portion 20 has a rectangular shape in a plan view. The center of the placement surface portion 20 is located at the highest position. The inclined support surface 38 is formed in a pyramidal shape with a plurality of independent inclined support surfaces 56 arranged around the center, each of which has the same inclination angle φ with respect to the horizontal plane and has a different friction coefficient with respect to the granular material 2 . In this embodiment, the inclined placement surface 38 is formed in a quadrangular pyramid shape by first, second, third and fourth independent inclined placement surfaces 56A, 56B, 56C and 56D having mutually different coefficients of friction with respect to the granular material 2. Further, in plan view, the four independent inclined placement surfaces 56A, 56B, 56C, and 56D are arranged in that order clockwise. The values ​​of the friction coefficient μ of the first, second, third, and fourth independent inclined support surfaces 56A, 56B, 56C, and 56D may be different from each other, and the combinations of the first, second, third, and fourth independent inclined support surfaces 56A, 56B, 56C, and 56D and the friction coefficient μ are not limited.

[0049] The operation of the particle size distribution measuring apparatus 10 according to the seventh embodiment will be briefly described with reference to the flow chart of FIG. First, a granular material to be subjected to particle size distribution measurement is collected, and the collected granular material is placed on the mounting surface 20 of the container 12G (steps S100, S102). In this embodiment, the granular material is placed in the center of the inclined placement surface 38 and around its periphery. Then, the shaker 14A starts to vibrate the inclined placement surface 38 (step S104). Due to the vibration of the inclined supporting surface 38, the granular material placed on the inclined supporting surface 38 is dispersed onto each of the four independent inclined supporting surfaces 56, and as each of the granular materials 2 that make up the granular material moves along the slope of the four independent inclined supporting surfaces 56, each of the granular materials 2 becomes separated and dispersed. That is, the granular materials 2 are held on the four independent inclined placement surfaces 56 at a distance from each other without overlapping or contacting each other.

[0050] When a predetermined vibration time has elapsed and the vibration by the shaker 14A has stopped, the imaging device 16A16A captures an image of the entire mounting surface 20 to obtain image data (step S106). That is, image data capturing an image of the entire area of ​​the four independent inclined placement surfaces 56 is acquired.

[0051] Thereafter, the image processing unit 18B calculates the area equivalent diameter of each granular material 2 as the particle size D, and the particle size distribution calculation unit 18C calculates a particle size accumulation curve corresponding to each of the four independent inclined supporting surfaces 56, and calculates the average value of the particle size accumulation curves corresponding to all of the independent inclined supporting surfaces 56 (steps S108 to S122). Then, the calculated particle size accumulation curve is output from output unit 18D, and the calculated particle size accumulation curve is transmitted from communication unit 18E to another terminal via network 36 (steps S124, S126). This completes the series of operations.

[0052] As mentioned above, the granular material is composed of a mixture of granular materials 2 with different physical properties, and it is believed that the ease with which the granular materials 2 disperse when moving along the inclined supporting surface 38 is affected by the differences in the physical properties of each granular material 2. Additionally, the ease of dispersion of the granular material 2 when moving on the inclined placement surface 38 is also considered to be affected by the combination of the physical properties of each granular material 2 and the friction coefficient of the inclined placement surface 38 . According to the seventh embodiment, the inclined placement surface 38 onto which the granular material 2 is introduced is formed of a plurality of independent inclined placement surfaces 56 each having a different coefficient of friction with respect to the granular material 2 . At this time, since the friction coefficient μ of each independent inclined mounting surface 56 is different, the conditions under which the granular material 2 rolls and moves are different for each independent inclined mounting surface 56 . Therefore, since the granular material 2 can be dispersed using independent inclined supporting surfaces 56 with different friction coefficients, it is advantageous in promoting the dispersion of the granular material 2 regardless of the physical properties of the granular material 2, and further, since image data when the granular material 2 is dispersed using multiple independent inclined supporting surfaces 56 can be obtained in a single operation, it is advantageous in improving the efficiency of the operation. Therefore, the particle size D of each granular material 2 can be accurately measured, which is advantageous for accurately calculating the particle size accumulation curve of the granular material 2, and is advantageous for efficiently and accurately evaluating the granular material. [Explanation of symbols]

[0053] 2 Granular material 10. Particle size distribution measuring device 12A-12G container 14 Vibration section 14A Shaker 1402 Main body 1404 Vibration Table 1406 Operation section 16 Imaging unit 16A Imaging device 18 Computers 18A input section 18B Image processing section 18C Particle size distribution calculation section 18D Output section 18E Communication Department 20 Placement surface section 21 Bottom wall 22 Side wall 26 Foundation 28 Stand 30 Input Devices 3002 Keyboard 3004 Mouse 32 Output Device 3202 Display 3204 Printer 34 External storage device 36 Network 38 Inclined mounting surface 40 Loading plate 4002 Support shaft 4004 Bearings 4006 Guide shaft 4008 Guide member 4010 Guide groove 42 Upper fixing part 4202 Female thread 4204 Cap screw 44 Lower fixing part 4402 Female thread 4404 Cap screw 46 Curved surface 48 Cone Surface 50 Independent tilting surface 52 plane 54 divided inclined mounting surface 56 Independent tilting surface C1, C2 particle size accumulation curve

Claims

1. A loading surface portion onto which a granular material having a mixture of granular materials of different particle sizes is loaded; a vibration unit that applies vibration to the placement surface to disperse the granular material on the placement surface; an imaging unit that captures an image of the granular material dispersed on the placement surface and generates image data; an image processing unit that calculates the particle size of the granular material based on the image data; a particle size distribution calculation unit that calculates a particle size accumulation curve showing a distribution of particle sizes of the granular material in the granular material based on the particle sizes of the granular material calculated by the image processing unit, The mounting surface portion is configured as an inclined mounting surface inclined with respect to a horizontal plane, The inclined placement surface is formed of a material having a large coefficient of friction with respect to the granular material. A particle size distribution measuring device characterized by:

2. The center of the placement surface is located at the highest position, The inclined support surface is formed in a pyramidal shape with a plurality of independent inclined support surfaces having different inclination angles with respect to a horizontal plane arranged around the central portion, The particle size distribution calculation unit calculates the particle size accumulation curve by calculating an average value of the particle size accumulation curves calculated for each of the independent inclined mounting surfaces.

2. The particle size distribution measuring device according to claim 1.

3. A plurality of divided inclined mounting surfaces having different inclination angles with respect to a horizontal plane are connected from a portion located at an upper end to a portion located at a lower end of the inclined mounting surface or the independent inclined mounting surface, The particle size distribution calculation unit calculates the particle size accumulation curve by calculating an average value of the particle size accumulation curves calculated for each of the divided inclined mounting surfaces.

3. The particle size distribution measuring device according to claim 1 or 2.

4. The center of the placement surface is located at the highest position, The inclined support surface is formed in a pyramidal shape with a plurality of independent inclined support surfaces arranged around the central portion, each of which has the same inclination angle with respect to a horizontal plane and has a different friction coefficient with respect to the granular material; The particle size distribution calculation unit calculates the particle size accumulation curve by calculating an average value of the particle size accumulation curves calculated for each of the independent inclined mounting surfaces.

2. The particle size distribution measuring device according to claim 1.

5. The mounting surface portion has an upwardly convex dome shape, The inclined placement surface is formed as a curved inclined placement surface facing upward of the placement surface portion.

2. The particle size distribution measuring device according to claim 1.

6. The mounting surface portion has an upwardly convex cone shape, The inclined mounting surface is formed as a conical surface forming an outer circumferential surface of the mounting surface portion.

2. The particle size distribution measuring device according to claim 1.

7. applying vibration to a loading surface portion onto which a granular material having a mixture of granular materials of different particle sizes is loaded, dispersing the granular materials on the loading surface portion; An imaging unit captures an image of the granular material dispersed on the placement surface to generate image data; Calculating the particle size of the granular material based on the image data; A particle size distribution measurement method for calculating a particle size accumulation curve showing a distribution of particle sizes of granular materials in the granular material based on the calculated particle sizes of the granular materials, With the placement surface portion tilted relative to a horizontal plane, the placement surface portion is vibrated to disperse the granular material on the placement surface portion, and then with the placement surface portion swung to position it on a horizontal plane, the image capture unit captures an image of the granular material with its optical axis perpendicular to the placement surface portion, thereby generating the image data. A particle size distribution measuring method comprising:

Images