JP5908381B2 - Image capturing device for particle size distribution measurement - Google Patents

Description

  The present invention relates to an image capturing apparatus used for particle size distribution measurement for measuring the particle size distribution of a material.

A batcher plant, a CSG (Cemented Sand and Gravel) mixing plant, or the like is used in the process of manufacturing concrete in the construction of a dam or the like.
In these plants, it is necessary to grasp the particle size distribution of materials for the quality control of concrete. In view of this, it has been proposed to photograph a material moving on a conveyance line and measure the particle size distribution of the material based on the photographing result (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2003-083868

  However, in the technique described in Patent Document 1, when the materials conveyed on the belt are overlapped, the aggregate is buried in the earth and is not photographed, and the particle size distribution cannot be measured accurately. There's a problem.

  Accordingly, an object of the present invention is to provide an image capturing apparatus that can solve the above-described problems and can improve the accuracy of measurement of the particle size distribution of the material.

In order to solve the above-mentioned problems, the present invention is an image capturing device for measuring a particle size distribution, and includes an inclined plate having a surface on which material flows down from an upstream side toward a downstream side, and a downstream side of the inclined plate. A downstream direction conversion unit, a screen provided on the downstream side of the downstream direction conversion unit, an illuminating unit that illuminates the screen, and an imaging unit that captures a material passing through the space on the front side of the screen from a horizontal direction. It is equipped with. The flow direction changing portion has two vertical plates, front and rear, and the material flowing down from the inclined plate toward the front passes between the two vertical plates. The screen is offset to the rear side with respect to the flow direction changing portion, and at least one of the vertical plates is formed with a plurality of protrusions protruding toward the other vertical plate.

In this configuration, the material can be diffused by flowing down the material along the surface of the inclined plate. Furthermore, since the material that has passed through the flow direction changing portion passes through a position away from the screen, the surface of the screen can be prevented from being soiled by the material. As a result, when the photographing unit photographs the material, the material does not overlap and the screen dirt is not photographed, so that the material on the image can be accurately recognized.
Moreover, the material that has flowed down from the inclined plate flows down in a straight line vertically downward by passing through the flow direction changing portion. Thereby, since the material flows down along a plane parallel to the imaging surface of the imaging element of the imaging unit, the size of the material can be accurately measured on the image.
Moreover, the screen is brightened by illuminating the screen with the illumination unit, and the material is photographed as a black shadow. Thereby, even when the material has a pattern, the outer shape of the material can be clearly recognized on the image.
Therefore, in the image photographing device of the present invention, the accuracy of the particle size distribution measurement performed based on the material image can be improved.
Moreover, compared with the conventional equipment configuration using the coarse and fine grain separation device, the equipment configuration of the particle size distribution measuring system can be reduced in size by providing the flow direction conversion unit.

Further, at least one of the vertical plates, a plurality of projections projecting toward the other of said vertical plate is formed, that material is in contact with the protrusions, fine material adhered to the coarse product materials Can be separated from the coarse particles before the material is photographed, and the material can be rectified.

  In the image capturing apparatus for measuring the particle size distribution described above, when the illumination unit is arranged on the rear side of the material passing through the space on the front side of the screen, the screen becomes brighter, so the outer shape of the material becomes clearer Can be recognized.

  In the image capturing apparatus for particle size distribution measurement described above, when a plurality of protrusions are formed on the surface of the inclined plate, the material flowing down the surface of the inclined plate can be effectively diffused and the material can be rectified. it can.

  In the image capturing device of the present invention, the accuracy of the particle size distribution measurement performed based on the material image can be improved.

It is a block diagram which shows the particle size distribution measurement system of this embodiment. It is a perspective view which shows the inclination board of this embodiment, a flow direction conversion part, and a screen.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In the present embodiment, a case will be described in which the image capturing device of the present invention is applied to a particle size distribution measuring system for measuring the particle size distribution of a material in a concrete manufacturing process.

  As shown in FIG. 1, the particle size distribution measuring system 1 is based on a belt conveyor 10 that conveys a material 3, an image photographing device 2 that photographs the material 3, and an image of the material 3 obtained from the image photographing device 2. A calculation unit 60 that calculates the particle size distribution of the material 3 and a hopper 80 in which the material 3 that has passed through the image capturing device 2 is accommodated.

  The image capturing device 2 is provided on the downstream side of the inclined plate 20 provided on the downstream side of the belt conveyor 10, the flow direction conversion unit 70 provided on the downstream side of the inclined plate 20, and the flow direction conversion unit 70. A screen 30, an illumination unit 40 that illuminates the screen 30, and a photographing unit 50 that photographs the material 3 that passes through the space on the front side of the screen 30 are provided.

The belt conveyor 10 is for supplying the granular material 3 containing a coarse particle material (such as aggregate) and a fine particle material (such as earth and sand) to an inclined plate 20 described later.
The belt conveyor 10 includes upstream and downstream pulleys 11, an endless belt 12 wound around both pulleys 11, and a motor (not shown) that rotates the upstream pulley 11.

The inclined plate 20 is a flat plate and has a surface 20a on which the material 3 flows down from the upstream side (rear side) to the downstream side (front side). The inclined plate 20 includes a pair of side walls 21 and 21 erected on both edges in the width direction of the surface 20a, and a plurality of protrusions 22 formed on the surface 20a (see FIG. 2).
The upstream edge of the inclined plate 20 is disposed below the downstream end of the endless belt 12. The inclined plate 20 is inclined so that the surface 20a is lowered from the upstream side toward the downstream side, and the material 3 discharged from the endless belt 12 flows down along the surface 20a to the front side.

  As shown in FIG. 2, the pair of side walls 21 are walls erected at both edges in the width direction of the surface 20 a of the inclined plate 20, and prevent the material flowing down on the surface 20 a from spilling sideways. . Further, the downstream end portions of the pair of side walls 21 protrude downstream from the downstream edge portion of the inclined plate 20.

The protrusion 22 is a triangular pyramid (Δ) protrusion that is detachably provided on the surface 20 a of the inclined plate 20, and has a posture in which one vertex of the bottom surface of the triangular pyramid faces the upstream side, and the vertical direction of the surface 20 a. Are arranged in stages (in this embodiment, four stages).
The plurality of protrusions 22 widely and thinly disperse the material flowing down on the surface 20a and rectify the material. The interval between the protrusions 22 is set so that the material passes between the protrusions 22 without clogging.

The flow-down direction conversion unit 70 is disposed on the downstream side of the inclined plate 20 and has two front and rear vertical plates 71 and 72 attached to an edge on the downstream side (front side) of the inclined plate 20.
The vertical plates 71 and 72 are flat plates formed with the same width as the width of the downstream (front) edge of the surface 20a, and are arranged such that the normal direction of the front and rear surfaces is the horizontal direction. The upper edge of the rear vertical plate 72 is attached to the downstream (front) edge of the surface 20 a by a hinge (not shown), and the upper edge of the front vertical plate 71 is downstream of the side walls 21. It is attached to the edge of the side (front side) by a hinge 71c.

As shown in FIG. 1, the two vertical plates 71, 72 are arranged in parallel in the front-rear direction, and the material 3 flowing down from the inclined plate 20 toward the front side of the vertical plates 71, 72 Flows in between. The front vertical plate 71 is extended above the upper end edge of the rear vertical plate 72 so that the material 3 flowing down from the inclined plate 20 does not jump out to the front side.
The distance between the two vertical plates 71 and 72 is not limited, but both the vertical plates 71 and 72 may flow smoothly between the two vertical plates 71 and 72 so that the material 3 flowing between the two vertical plates 71 and 72 flows smoothly. An interval of 71, 72 is set.

  A plurality of protrusions 71 b and 72 b are formed on the rear surface 71 a of the front vertical plate 71 and the front surface 72 a of the rear vertical plate 72. The protrusions 71b and 72b are rod-shaped members having a circular cross section that protrude in the horizontal direction on the rear surface 71a and the front surface 72a. On the rear surface 71a and the front surface 72a, a plurality of protrusions 71b and 72b are arranged at intervals in the vertical direction and the width direction.

  The material 3 that has flowed in between the two vertical plates 71 and 72 passes between the two vertical plates 71 and 72. At this time, the material 3 comes into contact with the rear surface 71a of the front vertical plate 71 and the front surface 72a of the rear vertical plate 72, and the movement of the material 3 in the front-rear direction is restricted. The component disappears and the flow direction of the material 3 becomes vertically downward. As a result, the material 3 that has passed through the flow-down direction conversion unit 70 flows down in a straight orbit (railway) vertically downward.

  In addition, in the case of the material 3 such as earth and sand having a high water content, a plurality of fine particles are attached to the coarse particles and become a dumpling. When such a material 3 is passed between the two vertical plates 71 and 72, the material 3 comes into contact with the plurality of protrusions 71b and 72b, whereby the coarse particles and the fine particles can be separated. it can.

As shown in FIG. 1, the screen 30 is a flat plate provided on the downstream side of the flow direction changing unit 70 (see FIG. 2). The screen 30 is arranged in parallel to both the vertical plates 71 and 72. Further, the screen 30 is offset to the rear side with respect to the rear vertical plate 72, and a gap in the front-rear direction is formed between the rear vertical plate 72 and the screen 30.
In addition, the screen 30 is arrange | positioned in the position away from the track | orbit (railway) of the material 3 so that the material 3 which flowed down between both the vertical plates 71 and 72 may not contact the surface 30a of the screen 30. FIG.

  The illumination unit 40 is a light source (light) that illuminates the surface 30 a of the screen 30, and is configured to irradiate the surface 30 a with light from a gap formed between the rear vertical plate 72 and the screen 30. . That is, the illumination unit 40 is disposed on the rear side of the material 3 that passes through the space on the front side of the screen 30.

  The hopper 80 accommodates the material 3 that has passed through the space on the front side of the screen 30. The upper opening portion of the hopper 80 is disposed below the downstream end portion of the screen 30.

  The photographing unit 50 is a camera that photographs the material 3 passing through the space on the front side of the screen 30 from the front side and outputs the photographing result to the calculating unit 60 described later. The photographing unit 50 is set to photograph the material 3 flowing down vertically from the horizontal direction. That is, the imaging surface of the imaging device of the imaging unit 50 is disposed on a plane parallel to the vertical direction. Note that the photographing unit 50 is preferably a video camera or a digital camera that can acquire a digital image.

  The calculation unit 60 is a computer including an input unit, an output unit, a CPU, a ROM, a RAM, and the like, acquires an image of the photographing unit 50, and calculates a particle size distribution of the material 3 based on the image.

Here, the calculation method of the particle size distribution by the calculation unit 60 will be described.
The imaging unit 50 shown in FIG. 1 captures the material 3 flowing from the upstream side toward the downstream side with the surface 30a of the screen 30 as the background. At this time, since the surface 30a of the screen 30 is illuminated by the illumination unit 40 on the rear side of the material 3 that passes through the space in front of the screen 30, only the surface 30a of the screen 30 becomes bright, and the material 3 has a black shadow. Taken as. Then, the calculation unit 60 binarizes the photographing result to calculate the size of the material 3.

In the particle size distribution measuring system 1 as described above, as shown in FIG. 1, the material 3 can be diffused by flowing down the material 3 along the surface 20 a of the inclined plate 20.
Furthermore, since the material 3 that has passed through the flow direction changing portion 70 passes through a position away from the screen 30, the surface 30a of the screen 30 can be prevented from being soiled by the material 3.
Thus, when the photographing unit 50 photographs the material 3, the material 3 does not overlap and the screen 30 is not photographed, so that the material 3 on the image can be accurately recognized.

In addition, the material 3 that has flowed down from the inclined plate 20 flows into the flow-down direction conversion unit 70 in a state having a horizontal direction velocity component, but by passing through the flow-down direction conversion unit 70, the horizontal speed component is changed. It disappears and flows down straight down. As a result, the material 3 that has passed through the flow-down direction conversion unit 70 flows down along a plane parallel to the imaging surface of the imaging device of the imaging unit 50.
If the material 3 passing through the front side of the screen 30 includes a velocity component in the horizontal direction, the falling trajectory of the material 3 becomes a parabola, and the distance from the imaging surface to each material 3 in the imaging region is the upper side of the imaging region. Therefore, the calculation unit 60 has a difference in spatial resolution. On the other hand, in the image photographing device 2 of the present embodiment, the distance from the imaging surface to each material 3 in the photographing region is constant, so that the size of the material 3 can be accurately measured on the image. .

  Further, by illuminating the screen 30 on the rear side of the material 3 passing through the space on the front side of the screen 30, the screen 30 becomes bright and the material 3 is photographed as a black shadow. Thereby, even when the material 3 has a pattern, the outer shape of the material 3 can be clearly recognized on the image.

Therefore, in the particle size distribution measuring system 1 using the image capturing device 2 of the present embodiment, the particle size distribution can be accurately measured based on the image of the material 3.

  In addition, the equipment configuration of the particle size distribution measuring system 1 can be reduced in size by providing the flow direction conversion unit 70 as compared with the conventional equipment configuration using the coarse and fine grain separation device.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
For example, the shape of the protrusion 22 of the inclined plate 20 is not limited to the triangular pyramid type (Δ type) described above, but the fin type (I type), the pin type (◯ type), and the bent portion of the folding plate are directed upward. A mold (saddle mold) or the like can be used. Furthermore, you may combine these some processus | protrusions.

  Further, the shape of the protrusions 71b and 72b of the vertical plates 71 and 72 is not limited to the above-described rod-shaped member (pin type) having a circular cross section, and a conical shape or a plate shape can be used. Furthermore, you may combine these some processus | protrusions.

  Further, the inclination angle of the inclined plate 20 and the height and direction of the protrusion 22 are appropriately set according to the size of the material 3 and the like.

DESCRIPTION OF SYMBOLS 1 Particle size distribution measurement system 2 Image pick-up device 3 Material 10 Belt conveyor 11 Pulley 12 Endless belt 20 Inclined plate 20a Surface 21 Side wall 22 Protrusion 30 Screen 30a Surface 40 Illumination part 50 Imaging part 60 Calculation part 70 Downflow direction conversion part 71 Front vertical Plate 71a Rear surface 71b Projection 72 Rear vertical plate 72a Front surface 72b Projection 80 Hopper

Claims (3)

An inclined plate having a surface from which the material flows down from the upstream side toward the downstream side;
A flow direction changing portion provided on the downstream side of the inclined plate;
A screen provided on the downstream side of the flow direction changing portion;
An illumination unit for illuminating the screen;
A photographing unit that photographs the material passing through the space on the front side of the screen from the horizontal direction,
The flow direction changing portion has two vertical plates, front and rear, and the material flowing down from the inclined plate toward the front passes between the vertical plates,
The screen is offset to the rear side with respect to the flow direction changing portion ,
An image photographing apparatus for particle size distribution measurement , wherein at least one of the vertical plates is formed with a plurality of protrusions that protrude toward the other vertical plate . The image illuminating device for particle size distribution measurement according to claim 1, wherein the illumination unit is arranged on the rear side of the material passing through the space on the front side of the screen. Wherein the surface of the inclined plate, the image capturing apparatus for particle size distribution measurement according to claim 1 or claim 2, wherein a plurality of protrusions are formed.

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