JP2003065937A - Particle size distribution measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a particle size distribution measuring instrument that is provided with a mechanism of successively supplying a plurality of kinds of samples to a particle size distribution measuring area and can automatically continuously measure the particle size distributions and the particle shape data of the samples. SOLUTION: This particle size distribution measuring instrument has a hopper 4 which has a sample throw-in hole and can supply stored samples; a sample throwing-in means 3 which selects one sample container 5 out of a plurality of sample containers 5, transports the selected container 5 to the vicinity of the throw-in port, and throws the sample contained in the container 5 into the hopper 4 through the throw-in port; and a transporting means 6 which supplies the sample supplied from the hopper 4 to the particle size distribution measuring area by transporting the sample. This measuring instrument also has a throwing-in control means 2 which controls the throwing-in means 3, a transportation control means 2 which controls the transporting means 6, and particle size distribution measuring means 2, 7, an 8 which measure the particle size distribution of the sample supplied to the measuring area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle size distribution measuring device for measuring the particle size distribution and particle shape data of various powder samples in the field of powder industry and the like. The present invention relates to a particle size distribution measuring device capable of supplying and automatically measuring particle size distribution and particle shape data.

[0002]

2. Description of the Related Art In the powder industry, a method of measuring the particle size (particle size distribution) of a powder sample with a particle size analyzer is widely used as a means for confirming the properties and quality of a powder product during development and production. It's being used. For this particle size distribution measurement, an image analysis method in which a falling sample particle group is photographed by a CCD camera or the like to measure the particle size distribution by image analysis and a statistical method, or a powder sample is irradiated with parallel light rays such as laser light There is a laser scattering / diffraction method in which a particle size distribution is calculated by measuring / analyzing a pattern of light diffracted and scattered by particles.

When a plurality of types of powder samples are measured, an operator puts the sample into a hopper for supplying the sample to perform the measurement, and when the measurement is completed, another sample is put into the hopper to perform the measurement. This operation is repeated for all the samples. Further, after the measurement of one type of sample is completed and before another sample is loaded into the hopper, the sample attached to the hopper and the sample transport path must be completely removed. If this removal operation is forgotten or is incomplete, different samples will be mixed in and an error will occur in the measurement result.

[0004]

As described above, in the conventional particle size distribution measuring apparatus, the work for measuring a plurality of types of powder samples is manual, which is complicated and requires a long time. It was For example, when introducing the measurement sample into the hopper, it is necessary to take care not to scatter the sample outside the hopper. If the sample is scattered outside the hopper, it must be completely removed. Further, the work of removing the measured sample at the time of switching the measurement sample is also a complicated and time-consuming work, and the presence or absence of this removal work and the quality thereof have a great influence on the measurement result.

Therefore, the present invention is equipped with a mechanism for sequentially supplying a plurality of types of samples to a measurement region, and is capable of automatically and continuously measuring the particle size distribution and particle shape data of a plurality of types of samples. The purpose is to provide a device.

[0006]

In order to achieve the above object, the particle size distribution measuring apparatus of the present invention comprises a sample charging port,
A hopper capable of supplying the sample stored therein and one sample container from a plurality of sample containers are selected and transported to the vicinity of the sample input port, and the sample in the sample container is transferred from the sample input port into the hopper. Sample feeding means for feeding the sample, a transporting means for transporting the sample supplied from the hopper to the measurement area of the particle size distribution, a loading control means for controlling the sample loading means, and a controlling the transporting means. It has a conveyance control means and a particle size distribution measuring means for measuring the particle size distribution of the sample in the measurement area.

In the above particle size distribution measuring device,
The sample loading means has a gripping part for gripping the sample container, a moving part for moving the gripping part in three directions orthogonal to each other, and a rotating part for rotating the gripping part around a horizontal rotation axis. It is preferably one.

Further, in the above particle size distribution measuring device,
The loading control means simultaneously controls the driving of the moving part and the rotating part of the sample loading means, and controls the loading of the sample in the sample container from the lowest position to the sample loading port. It is preferable to do it.

In the above particle size distribution measuring device,
The hopper is provided so as to be movable in the vertical direction,
It is preferable that the transfer control means controls the supply amount of the sample to the measurement region by controlling the drive of the transfer means and the vertical position control of the hopper.

In the above particle size distribution measuring device,
It is preferable that the transport control means increases the transport capability of the transport means when the measurement of one type of sample is completed and forcibly discharges the sample remaining in the transport means.

In the above particle size distribution measuring device,
It is preferable that the particle size distribution measuring means detects the image data of the sample in the measurement region by an image sensor and measures the particle size distribution of the sample by the image data.

Further, in the above particle size distribution measuring device,
It is preferable that the transport control unit controls the supply amount of the sample to the measurement region based on the image data detected by the image sensor.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a particle size distribution measuring device 1 of the present invention. Particle size distribution measuring device 1
Is composed of the measuring device body 10 and the computer 2. The computer 2 performs various data processing related to measurement and controls each part of the measuring device body 10. As the computer 2, a general-purpose personal computer (so-called personal computer) or the like can be used.

The computer 2 has a display section 21 for displaying characters and figures, an input section 22 for an operator to input data, and a printer 23 for printing characters and figures.
Are connected. The display unit 21 is a CRT,
A liquid crystal display, an EL display panel or the like can be used, and a keyboard, mouse, tablet or the like can be used as the input unit 22.

The image signal from the CCD camera 7 is input to the computer 2 via the image processing board 24. The lens 71 of the CCD camera 7 is preferably a telecentric lens or the like in which the image size does not change even if the distance from the particles to be photographed to the lens 71 changes. The image processing board 24 holds image data at the time of image capturing and performs contour line extraction of particle images and various other image processing. The computer 2 further processes the image-processed image signal to analyze the particle size and particle shape of the sample by an image analysis method.

That is, the particle size of each particle is calculated, the volume of the particle is calculated from the particle size data, the amount of particles in each predetermined particle size category is calculated, and the particle size distribution is calculated from these results. To do. In addition, various parameters relating to the particle shape, such as the ratio of the major axis to the minor axis of the particle, can be calculated from the particle image. The calculated particle size distribution and various parameters can be displayed on the display unit 21 or printed by the printer 23.

The light source 8 is the sample 5 with respect to the CCD camera 7.
It is placed at a position opposite to each other with 1 in between. The CCD camera 7 captures an image in the measurement area 72 by using transmitted light as a projection image of sample particles. Here, the light source 8 is of a transmitted light type, but the light source may be placed on the same side as the CCD camera 7 with respect to the sample 51, and image pickup may be performed by reflected light. Further, the light emitted from the light source 8 can be photographed with either stationary light or strobe light. The light source 8 can be turned on / off and the amount of light emission can be controlled by controlling the light source power source 81 by the computer 2.

The sample 51 for measuring the particle size distribution is supplied from the hopper 4 to the vibrating feeder 6, and is conveyed to the left end of the vibrating feeder 6 which is vibrated by the vibrating device 61. The sample 51 reaching the left end of the vibrating feeder 6 drops and moves from the left end of the vibrating feeder 6 toward the measurement area 72. The drop movement may be a drop movement by free fall or a drop movement to which an external force such as an air flow is added. An image of the sample 51 in the measurement area 72 is photographed by the CCD camera 7, and the image signal is subjected to the grain analysis of the image analysis method as described above.

The frequency and amplitude of the vibration generated by the vibrating device 61 can be controlled by the computer 2. Also,
The hopper 4 can adjust the vertical position by the vertical position adjusting mechanism 42. The vertical position of the hopper 4 can also be controlled by the computer 2. Therefore, the conveyance capability of the vibration feeder 6 can be adjusted by controlling the vibrating device 61, and the sample supply amount from the hopper 4 can be adjusted by controlling the vertical position of the hopper 4.

Thus, the computer 2 can control so that the sample supply amount from the vibration feeder 6 to the measurement area 72 becomes an optimum value. To do this, the sample concentration and the like are automatically obtained from the photographed image of the measurement region 72, and the conveyance capacity of the vibration feeder 6 and the vertical position of the hopper 4 are controlled so that the sample concentration in the measurement region 72 becomes the optimum value. Good. By doing so, it is possible to perform control so as to maintain the sample concentration at an optimum value without separately providing a sensor or the like for detecting the sample concentration.

The sample 51 whose particle size distribution has been measured falls on the measured container 9 and is accumulated. The measured sample in the measured container 9 is processed such as carried out and discarded after an appropriate period. A belt conveyor or the like may be provided in place of the measured container 9 to automatically carry out the measured sample to the outside of the measuring device body 10.

On the upper part of the measuring device body 10, a sample loading device 3 for automatically supplying a sample is provided. The upper region of the measuring device body 10 is completely separated from the lower region where the measurement is performed by a partition plate 11. FIG. 2 is a plan view of the upper region of the measuring device body 10 as seen from above. Next, the configuration of the sample introduction device 3 will be described with reference to FIGS. 1 and 2.

On the partition plate 11, a plurality of sample containers 5 each containing a different sample are placed. The sample loading device 3 may select one sample container 5 from the plurality of sample containers 5 and hold it, convey it to the position of the hopper 4, and load the sample in the sample container 5 into the hopper 4. it can. The upper surface of the hopper 4 is open as a sample inlet 41. In this way, by sequentially loading different types of samples in the plurality of sample containers 5 into the sample loading port 41, it is possible to automatically and continuously measure multiple types of samples. In the example shown in FIGS. 1 and 2, eight kinds of samples can be continuously measured. The sample injection device 3
Are controlled by the computer 2.

Guide rails 31 and 31 are provided on the partition plate 11 in the X-axis direction, which is the left-right direction in FIGS. An X-axis moving body 32 is provided on the guide rail 31 so as to be movable in the X-axis direction. X-axis moving body 32
A columnar guide member 33 is erected on the top in the vertical direction. The columnar guide member 33 is provided with a Y-axis moving body 34 that is movable in the vertical direction, that is, the Y-axis direction. The Y-axis moving body 34 is provided with a Z-axis moving body 35 that is movable in the front-rear direction, that is, the Z-axis direction.

A grip portion 36 is provided adjacent to the Z-axis moving body 35. The grip portion 36 is provided with two fingers 37 that can be opened and closed, and the fingers 37 can be driven to grip the sample container 5. Further, the grip portion 36 can be rotated around a rotation axis parallel to the X axis, and can be rotated and stopped at an arbitrary angular position around this rotation axis. The control of the rotation direction of the grip 36 will be referred to as θ-axis control. That is, the gripper 36 can be moved and controlled in the X, Y, and Z axis directions that are the three orthogonal axis directions, and can also be rotationally controlled in the θ axis direction about the rotation axis parallel to the X axis.

The moving mechanism in the X-, Y-, and Z-axis directions and the turning mechanism in the θ-axis direction of the grip portion 36 are composed of a motor, a feed screw mechanism, and the like, which are not shown. For example, a motor for rotating the grip 36 is provided in the Z-axis moving body 35. These X, Y of the gripper 36,
The movement mechanism in the Z-axis direction, the rotation mechanism in the θ-axis direction, and the opening / closing drive mechanism of the fingers 37 are all controlled by the computer 2.

Next, the operation of the particle size distribution measuring device 1 will be described. First, a plurality of sample containers 5 containing powder samples to be measured are placed at predetermined positions on the partition plate 11. And
When the continuous measurement is instructed from the computer 2, the sample loading device 3 holds the sample container 5 in the specified order and holds the hopper 4
The sample in the sample container 5 is transported to the position
Throw in 1. The empty sample container 5 after the sample is loaded is
Return to the original mounting position. The position of the sample container 5 when gripped by the sample loading device 3 can be determined from an image obtained by a television camera or the like (not shown).

When the sample is loaded, the hopper 4 is at the lowest position, that is, the lowest part of the hopper 4 is at the vibration feeder 6.
Has been lowered to a position where it comes into contact with the transport surface of. In this state, even if the powder sample is put into the hopper 4, the powder sample does not spread on the conveying surface of the vibrating feeder 6. When the sample loading by the sample loading device 3 is completed, the hopper 4 is raised to a predetermined position, the vibration feeder 6 is driven, and the loaded sample 51 is supplied to the measurement area 72. Then, an image of the sample 51 is taken by the CCD camera 7, and the particle size distribution and the like as described above are measured by this image signal.
Further, during the measurement, the carrying capacity of the vibrating feeder 6 and the vertical position of the hopper 4 are controlled so that the sample concentration in the measurement area 72 becomes an optimum value.

When the measurement of one sample is completed, air is ejected from the air ejector (not shown) toward the wall surface of the hopper 4 to forcibly discharge the residual sample, and the conveyance capacity of the vibration feeder 6 is close to the maximum value. The sample remaining on the transport surface is forcibly discharged. In this way, by forcibly discharging and removing the sample remaining in each part at the end of the measurement, it is possible to prevent the measured sample from mixing with the next sample and causing an error in the measurement result.

When the removal of the residual sample is completed, the sample loading device 3 holds the next sample container 5 and conveys it to the position of the hopper 4, and loads the next sample into the sample loading port 41. And
Measure the particle size distribution of the next sample. In this way, the samples in the sample container 5 can be put into the hopper 4 in a predetermined order to continuously measure the particle size distribution and the like. When the measurement of the samples in all the sample containers 5 is completed, the residual sample is removed and then a series of continuous measurement operations is completed. The progress of the measurement work can be confirmed by displaying an image of the sample container 5 on the display unit 21 by a television camera (not shown) or the like.

FIG. 3 is a diagram showing details of the sample loading operation of the sample loading device 3. The sample loading device 3 conveys the sample container 5 gripped by the grip portion 36 to a position near the sample input port 41 of the hopper 4, and then the grip portion 36 is rotated in the θ-axis direction to incline the sample container 5. A sample is loaded into the sample loading port 41. At that time, if the sample container 5 is tilted at a distant position above the sample input port 41, part of the sample in the sample container 5 may fall outside the sample input port 41 and be scattered.

In order to prevent such scattering of the sample to the outside of the sample inlet 41, the sample inlet 3 of the present invention is used.
In the case where the sample container 5 does not come into contact with the hopper 4, the sample container 5 is tilted and the sample is loaded while keeping the sample container 5 as low as possible. Further, the sample loading position is made as close as possible to the central axis C of the sample loading port 41.

When the sample container 5 is tilted to start the sample loading, as shown in FIG. 3, the sample container 5 does not come into contact with the hopper 4, and the sample loaded is not scattered outside the sample loading port 41. Then, the sample container 5 is located at the lowest position. Then, as indicated by reference numerals 5a, 5b, 5c, and 5d, the sample is loaded while gradually increasing the rotation angle of the sample container. At this time, the gripper 36 is moved in the Y-axis direction and the Z-axis direction in synchronization with the rotation of the gripper 36 in the θ-axis direction,
The sample container 5 is kept as low as possible, and the sample input position is kept near the central axis C of the sample input port 41.

As described above, when the sample is loaded, the θ of the grip portion 36 is
By simultaneously controlling the rotation in the axial direction and the movement in the Y-axis direction and the Z-axis direction, while keeping the sample container 5 as close to the sample inlet 41 as possible as low as possible, the sample is placed near the center of the sample inlet 41. It becomes possible to throw in. Thereby, it is possible to prevent the sample from falling out of the sample inlet 41 and being scattered.

As described above, the sample introduction device allows the samples in the sample container to be introduced into the hopper in a predetermined order to continuously measure the particle size distribution and the like. Since the loading operation of the sample into the hopper can be programmed to minimize the scattering of the sample, accurate measurement can be automatically performed without being affected by the skill level of the operator. . Further, since the residual sample removing operation after the measurement is automatically performed, it is possible to prevent an error in the measurement result due to the mixing of different samples.

In the above embodiments, a CCD camera (area sensor) is used as an image sensor in the image analysis method, but a MOS type area sensor or a line sensor type photographing device may be used. It can also be used. When a line sensor is used, a two-dimensional image of the entire particle can be obtained by continuously and repeatedly acquiring a one-dimensional image corresponding to the falling movement of sample particles. Further, not only one image sensor such as a CCD camera but also a plurality of image sensors can be provided.

Further, the particle size distribution measuring means is not limited to the image analysis method shown in the above-mentioned embodiment, but a known laser scattering / diffraction method or other means may be used. . Further, although only one computer, display device, printer and the like are installed, a plurality of devices may be installed. Further, although the sample introduction device and the vibration feeder are controlled by the same control means (computer 2), these controls may be performed by different control means.

Further, as the conveying means, any conveying device such as a belt conveyor can be used in addition to the vibrating feeder. Further, when removing the sample remaining on the hopper or the transport surface, it is also effective to use an ionizer or the like together to remove static electricity to facilitate removal of the residual sample.

[0039]

Since the present invention is constructed as described above, it has the following effects.

Since a plurality of kinds of samples are sequentially charged into the hopper by the sample charging means to measure the particle size distribution and the like, it is possible to continuously and automatically measure the plurality of kinds of samples. Therefore, no labor is required for measuring a plurality of types of samples, and the measurement itself can be completed in a short time.

The sample loading means includes a gripping part for gripping the sample container, and a moving part for moving the gripping part in three orthogonal directions.
Since the grip has a rotating part that rotates the grip about a horizontal rotation axis, the grip has a large degree of freedom of movement,
A wide range of sample containers can be accommodated.

Since the loading control means controls the driving of the moving part and the rotating part at the same time so as to load the sample in the sample container from the lowest position to the sample loading port, scattering of the sample is performed. Can be minimized to reduce the possibility of mixing different kinds of samples and improve the measurement accuracy.

Since the supply amount of the sample to the measurement region is controlled by the vertical position control of the hopper and the drive control of the transport control means, the sample concentration in the measurement region can be maintained at the optimum value. The measurement accuracy can be improved.

Since the transport control means increases the transport capacity of the transport means at the end of the measurement to forcibly discharge the remaining sample, it is possible to prevent the occurrence of a measurement error due to mixing of different samples.

Since the particle size distribution measuring means is of the image analysis type, not only the particle size distribution of the sample but also the shape of the sample particles can be measured. Therefore, it is possible to calculate parameters relating to the shape, such as the ratio of the major axis to the minor axis of the particles, and it is also possible to accurately obtain various indexes and the like calculated from the particle size distribution.

Since the transport control means controls the supply amount of the sample to the measurement area based on the image data detected by the image sensor, the measurement can be performed without installing a special detection means for detecting the sample concentration. The sample concentration in the region can be maintained at the optimum value, and the measurement accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a particle size distribution measuring device of the present invention.

FIG. 2 is a plan view of the upper region of the measuring device body as seen from above.

FIG. 3 is a diagram showing details of a sample loading operation of the sample loading device.

[Explanation of symbols] 1. Particle size distribution measuring device 2 ... Computer 3 ... Sample loading device 4 ... Hopper 5 ... Sample container 6 ... Vibration feeder 7 ... CCD camera 8 ... Light source 9 ... Measured container 10 ... Measuring device body 11 ... Partition board 21 ... Display 22 ... Input section 23 ... Printer 24 ... Image processing board 31 ... Guide rail 32 ... X-axis moving body 33 ... Columnar guide member 34 ... Y-axis moving body 35 ... Z-axis moving body 36 ... Grip 37 ... Finger 41 ... Sample inlet 42 ... Vertical position adjustment mechanism 51 ... Sample 61 ... Excitation device 71 ... Lens 72 ... Measuring area 81 ... Power source for light source

Claims (7)

[Claims] 1. A hopper (4) having a sample inlet (41) capable of supplying a sample (51) stored therein, and one sample container (5) selected from a plurality of sample containers (5). The sample (51) in the sample container (5), and the sample (51) in the sample container (5) is conveyed to the vicinity of the sample input port (41).
Sample loading means (3) for loading the above into the hopper (4)
And a feeding means (6) for feeding the sample (51) fed from the hopper (4) and feeding it to the measurement region (72) of particle size distribution, and a loading control for controlling the sample loading means (3). Means (2)
A transport control means (2) for controlling the transport means (6), and a particle size distribution measurement means (2, 7, 8, 24) for measuring the particle size distribution of the sample (51) in the measurement area (72). ) And a particle size distribution measuring device having. 2. The particle size distribution measuring apparatus according to claim 1, wherein the sample introducing means (3) includes a gripping part (36) for gripping the sample container (5), and the gripping part (36). A particle size distribution measuring apparatus comprising: a moving part (31 to 34) for moving in three directions orthogonal to each other, and a rotating part (35) for rotating the gripping part (36) around a rotation axis in the horizontal direction. 3. The particle size distribution measuring apparatus according to claim 2, wherein the feeding control means (2) comprises the moving portion (31 to 34) and the rotating portion (35) of the sample feeding means (3). ) Are simultaneously controlled to move the sample (51) in the sample container (5) from the lowest position to the sample inlet (4).
A particle size distribution measuring device for controlling so as to be put into 1). 4. The particle size distribution measuring apparatus according to claim 1, wherein the hopper (4) is provided so as to be vertically movable, and the transfer control means (2) is provided. ) By the drive control of the transfer means (6) and the vertical position control of the hopper (4),
A particle size distribution measuring device for controlling the supply amount of the sample (51) to the measurement region (72). 5. The particle size distribution measuring apparatus according to any one of claims 1 to 4, wherein the transport control means (2) comprises the transport means (when the measurement of one type of sample is completed. A particle size distribution measuring apparatus for increasing the carrying capacity of 6) and forcibly discharging the sample remaining in the carrying means (6). 6. The particle size distribution measuring device according to claim 1, wherein the particle size distribution measuring means (2, 7, 8, 24) is in the measuring area (72). A particle size distribution measuring device for detecting image data of the sample (51) by an image sensor (7) and measuring a particle size distribution of the sample (51) by the image data. 7. The particle size distribution measuring apparatus according to claim 6, wherein the conveyance control means (2) uses the image data detected by the image sensor (7) to measure the measurement area (72).
A particle size distribution measuring device for controlling the supply amount of the sample (51) to the sample.