JPH06218331A - Method and device for measurement of sieving - Google Patents

Abstract

PURPOSE:To make it possible to measure the weight of each sieve directly and efficiently with high precision by lifting up all sieves above a sieve to be measured, then separating the former from the latter, and hoisting up the sieve to be measured and supporting it to measure its weight. CONSTITUTION:Sieves 8a to 8e are stacked up, then powder is loaded in a top sieve, and these sieves 8a to 8e are shaken to sieve the powder. After that, the weight of the sieved powder is determined by the size of grain by measuring the weight of each sieve 8a to 8e sequentially. Then when measuring the weight of each sieve 8a to 8e, an object to be measured, e.g. the sieves 8b to 8e stacked above the sieve 8a are slightly heaved up collectively and supported as they are to their lifted position. At the same time, the sieve to be measured 8a is lifted separated from the sieves above and below the sieve 8a, and is measured in such a state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for sieving various powders and measuring the weight by particle size.

[0002]

2. Description of the Related Art Sand as a fine aggregate, which is a material for concrete, is subjected to a sieving test based on the "aggregate sieving test method" specified in JIS A 1102 to calculate the coarse grain ratio. There is a need to.

The test method specified in JIS uses 8 to 10 types of standard sieves with different openings,
The sieves with the larger openings are stacked on top of each other and mounted on a sieve shaker, and a certain amount of sample is put into the uppermost sieve. Then, when the shaker is activated, small particles with a small particle size are successively dropped to the lower sieve and sieved according to the particle size.After sufficient sieving, the weight of the sample remaining on each sieve is measured. Then, the coarse grain ratio is calculated from the measured value.

In this case, it is specified that the sieving work prior to the measurement is performed "until 1% or more of the amount of the sample remaining in each sieve in 1 minute does not pass through the sieve". In other words, it is judged that sufficient sieving was performed when the amount of passing through the sieve by shaking for 1 minute was less than 1% of the sample remaining in each sieve.

Therefore, in general, the sieving is generally 1
After doing this for about a minute, all the sieves are weighed, and the amount of sieve passing per minute is calculated by comparing with the previous measured value, and it is judged each time whether it meets the above conditions. However, such work is usually repeated many times, and there has been a demand for an effective improvement measure capable of efficiently performing such a remarkably troublesome work.

For example, as a device for automatically sieving a minute amount of powder of a drug or the like and weighing according to particle size, a balance for weighing a plurality of sieves in a stacked state and a plurality of sieves stacked in a stacked state are used. A sieving measuring instrument equipped with a shaking machine that applies vibration by sound waves to perform sieving and a sieving machine equipped with a robot hand for transferring the sieve between the balance and the shaking machine and lifting a predetermined number of sieves has been put into practical use. There is.

In the measuring instrument, when a plurality of sieves are stacked and set on the balance, the robot hand repeatedly performs the weighing while lifting and separating the sieves one by one from the top, and each sieve is judged from the difference of each measured value. Weigh the tare. Then, the medicine is put into the uppermost stage of the stacked plural sieves, the robot hand grasps all of the sieves and transfers them to a shaker, and sonic vibration is applied to each sieve by the shaker to perform sieving. After that, the robot hand grasps all the sieves and returns them to the balance, and again the robot hand lifts each sieve one by one and repeats the measurement while separating and obtains the weight of each sieve from the difference of each measured value. The data for each particle size of the drug is calculated from the above data and the tare weight previously obtained.

[0008]

The measuring instrument as described above realizes automation of sieving and weighing operations. However, since the shaker in the measuring instrument uses sound waves, it is not expensive. Inevitably, and because a large number of stacked sieves are transferred by the robot hand between the balance and the shaker, a high-performance and expensive robot hand capable of performing complicated operations is essential. In addition, since the work is performed while transferring the sieve by the robot hand, it requires a working time for that. Therefore, even if such a measuring instrument is suitable for sieving medicines and the like, it can be used as a fine aggregate. It is not always effective in terms of cost and work efficiency to adopt it when sieving sand and measuring it.

Further, in the above-mentioned measuring device, from the state where all the sieves are piled up, each sieve is lifted one by one by the robot hand and repeatedly weighed while being separated, and the weight of each sieve is obtained from the difference of each measured value. Therefore, the balance must be capable of measuring a wide range from all sieves to one sieve, and such a balance does not always provide sufficient weighing accuracy.

The present invention has been made in view of the above circumstances, and an effective method and an apparatus therefor capable of efficiently and accurately sieving powder such as sand used as fine aggregates and performing weight measurement according to particle size. Is intended to provide.

[0011]

According to a first aspect of the present invention, a plurality of sieves having different openings are piled up and down with the larger openings being placed on top of each other, and the powder is put into the uppermost sieve. Then, the sieves are shaken to drop the ones with a small particle size to the lower sieve one by one, and after sieving, the weight of each sieve is sequentially measured individually to obtain the weight of the powder by particle size. And by lifting and supporting the sieve directly above the sieve to be measured, all the sieves above the sieve to be measured are lifted together to separate them from the sieve to be measured, and then the sieve to be measured. Is individually lifted and supported to separate it from the upper and lower sieves and measure its weight.

The invention described in claim 2 is the same as claim 1.
An apparatus for carrying out the above method described in 1), wherein a plurality of sieves mounted in a vertically stacked state are shaken so that the powder put into the uppermost sieve is sieved. A shaker and a support arm that can be raised and lowered on the side of the shaker and is extendable on the shaker side and that lifts and supports the sieve directly above the sieve to be weighed at its tip end, It is provided below the support arm so that it can be lifted up and down and can be expanded and contracted on the shaker side to lift and support the sieve to be weighed at its tip and to measure the weight of the sieve by the load cell incorporated in the tip. And a control device for controlling the operation of the support arm and the measurement arm and managing the measurement data. It is intended.

[0013]

In the method of the present invention, a plurality of sieves are stacked, the powder is put into the uppermost sieve, the sieves are shaken to screen the powder, and then the weight of each sieve is measured individually. Determine the weight of the powder that has been screened and sorted by particle size. When measuring the weight of individual sieves, the sieves stacked above the sieve to be measured are collectively lifted slightly and supported at that position, and the sieve to be measured is slightly lifted and supported. By doing so, the sieve to be measured is completely separated from the upper and lower sieves, and the measurement is performed in that state.

In the apparatus of the present invention, the weight of each sieve is measured after the stacked sieves are shaken by a shaker. At that time, the support arm is raised to raise the weight of the sieve to be measured. The upper sieves are collectively lifted and supported, and the sieve to be measured is lifted and supported by raising the measuring arm, and the load cell installed at the tip of the measuring arm performs weighing. The operation of the support arm and the measurement arm is controlled by the control device, and the measurement data is managed by the control device and appropriately processed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of a sieving measurement device according to the present invention. This device is to obtain the coarse particle ratio of sand as fine aggregate which is a material for concrete,
A sieving test for sieving a sample according to particle size in five steps to obtain a weight for each particle size, comprising a shaker 1, a supporting arm 2, a measuring arm 3, and a controller 4. Has been done.

The shaker 1 comprises a shaking table 5 and a main body portion 6 having a vibrating mechanism for vibrating the shaking table 5 vertically and horizontally.
Sieve 8 (8a-on the shaking table 5 through the saucer 7)
8e) is stacked and mounted in five stages.

The sieve 8 is for sieving the sample according to the particle size, and as shown in FIG.
The upper part of the lower part of the body 9 is inserted into the upper part of the body 9 of the lower sieve 8 in such a manner that the larger the mesh size (the coarser the size of the wire mesh 10) is, the more the upper and lower parts are stacked. It is a thing. Then, the stacked sieves 8 are mounted on the shaking table 5, and a certain amount of the sample is put into the uppermost sieve 8e and the shaking table 5 is vibrated. Sifting is done by falling on the lower sieve 8.

In FIG. 1, reference numeral 11 is a lid that covers the uppermost sieve 8e, 12 is a column for supporting the lid 11 via the mounting metal fitting 13, and 14 is both columns of the mounting metal fitting 13 at both ends. It is a fixing screw for fixing by screwing against the sample, and the sample is placed on the uppermost sieve 8e.
When the sieving process is performed, the fixing screws 14 and 14 are loosened and the lid 11 is pulled up. When sieving is performed, the lid 11 is covered to prevent the sample from splashing out, and the lid 11 shakes the entire sieving table 5. It is pressed against the to prevent it from falling. Further, on each of the sieves 8, engagement pieces 15 with which the tip portions of a support arm 2 and a measurement arm 3 which will be described later are engaged are attached so as to project to both sides.

Two columns 21 are provided on the side of the shaker 1.
Are provided upright and supported by the columns 21 so that the support arm 2 can be moved up and down. That is, as shown in FIGS. 2 and 3, a base 22 which is guided by the two columns 21 and which can be raised and lowered is provided.
A servo motor 23 is mounted on the shaft of the servo motor 23, and a pinion 24 attached to the shaft of the servo motor 23 meshes with a rack 25 formed on one side of the support column 21. By rotating the pinion 24 and the rack 25, the base 22
Is designed to go up and down. Reference numeral 26 is an encoder for detecting the operation amount of the servo motor 23 so as to position the base 22.

The support arm 2 has a base 22.
Are mounted substantially horizontally on both sides of the machine, with their tips facing the shaker 1 side. As the supporting arms 2, those having a rod 27 which can expand and contract, such as an air cylinder or a hydraulic cylinder, are adopted, and a support for supporting the above-mentioned engaging piece 15 for lifting the sieve 8 is provided at the tip of these rods 27. A member 28 is attached.

The above-mentioned measuring arm 3, which is movable up and down like the support arm 2 and is extendable and retractable toward the shaker 1 side of the rod 31, is attached to the base 32 of the support arm 2 of the support arm 2. It is provided below. Like the support arm 2, the measuring arm 3 is also moved up and down by rotating the pinion 33 meshing with the rack 25 by a servo motor 34, and is provided with an encoder 35 for positioning the pinion 33. This measuring arm 3 rod 3
A support member 36 that supports the engaging piece 15 of the sieve 8 is attached to the tip end of the No. 1, and a load cell 37 to which the load of the sieve 8 is applied when the sieve 8 is lifted is attached to the support member 36. The load cell 37 measures the weight of the sieve 8.

The shaker 1, the support arm 2, and the measuring arm 3 are configured to operate under the control of the control device 4 through a cable and a preset program. In addition, the weighing data by the load cell 37 is input to the control device 4 through a cable, and the control device 4 stores the input data and appropriately processes them, and calculates and displays desired data to display or print out. It is said that.

The work procedure of the sieving test by the apparatus having the above-mentioned structure will be described with reference to FIGS. 5 and 6.

First, as shown in FIG. 2, both the supporting arm 2 and the measuring arm 3 are made to stand by at a predetermined position in a retracted state, and in that state, the sieves 8 are stacked and shaken on the shaking table 5. After mounting, a specified amount of sample is put into the uppermost sieve 8e, and the lid 11 is put on and fixed. Lid 11
The fixing screw 14 for fixing the can be tightly tightened to the column 12, but if there is no fear that the lid 11 will fall out due to its own weight and there is no concern that the sieve 8 will fall, It is preferable that the lid 11 is loosely tightened so that the lid 11 can be naturally lifted together with the sieve 8 when the sieve 8 is lifted. In addition, the tare weight of each sieve 8 is obtained in advance by an appropriate measuring device (or by this device).

When the shaker 1 is operated, small particles in the sample gradually fall from the uppermost sieve 8e to the lower sieve 8 and are sieved, so that a predetermined time is set in advance. After the lapse of time, the shaker 1 is stopped and each sieve 8 is individually weighed. The order of the measurement is arbitrary, but the case of performing the measurement from the lowest step will be described.

First, as shown in FIG. 1, the measuring arm 3 is arranged at the position of the lowermost sieve 8a to be weighed, and the supporting arm 2 is placed directly above the sieve 8b.
, And the respective rods 31, 27 are extended until their supporting members 36, 28 are located below the engaging pieces 15, 15 of the sieves 8a, 8b, respectively. Then, first, by operating the servo motor 23 to raise the support arm 2, as shown in FIG. 5, all of the sieves 8b to 8e above the lowermost sieve 8a to be measured are collectively lifted and supported as they are. Then, the sieves 8b to 8e are separated from the lowermost sieve 8a to be measured. On this occasion,
When the fixing screw 14 of the lid 11 is only loosely tightened, the lid 11 is also lifted together, but when the fixing screw 14 is tightly tightened, the work of loosening it beforehand is performed.

Next, as shown in FIG. 6, the measuring arm 3 is lifted to lift the sieve 8a to be weighed and separated from the pan 7. At this time, the lifting stroke of the measuring arm 3 is set so that the sieve 8a is completely lifted from the pan 7, and the sieve 8a to be measured that is lifted in such a manner does not come into contact with the sieve 8b immediately above it. Then, the rising stroke of the support arm 2 is set.
As a result, only the weight of the sieve 8a containing the sample inside is applied as a load to the measurement arm 3, the load is detected by the load cell 37, and the data is input to the control device 4 and stored.

Since the weighing of the lowermost sieve 8a has been completed, the measuring arm 3 is lowered to put the sieve 8a into the pan 7
After lowering, the support arm 2 is lowered and each sieve 8
b-8e are lowered onto the sieve 8a, and the rods 27 and 31 of the arms 2 and 3 are retracted. And each arm 2, 3
Is raised by one stage, and thereafter, the measurement is performed by using the second-stage sieve 8b from the bottom as a measurement target by the same procedure as above. In other words, the upper 3 stages of sieve 8c ~
8e are collectively lifted by the support arm 2 and then the sieve 8b to be measured is lifted by the measuring arm 3 to be separated from the lowermost sieve 8a.
7 weighs. The above procedure is sequentially repeated to the uppermost sieve 8e, and all the sieves 8a to 8e
The measurement data of is stored in the control device 4. Needless to say, when the uppermost sieve 8e is weighed, the sieve 8e only needs to be lifted by the measuring arm 3 and the support arm 2 may be retracted upward.

Next, the shaker 1 is operated and further sieving is performed for about 1 minute, and then each sieve 8 is weighed again in the same manner as described above. Then, the control device 4 compares the data obtained this time with the data obtained previously to determine whether or not sufficient sieving is performed according to JIS.
Judgment based on the provisions of. That is, it is judged by comparing the data before and after whether the amount of passing through the sieve due to the shaking for about 1 minute is less than 1% of the sample remaining in each sieve 8. If the condition is not satisfied, sieving and weighing are further repeated for about 1 minute until the condition is satisfied, and at the time when the condition is satisfied, "1% or more of the amount of the sample remaining in each sieve in 1 minute is Complete the sieving work that is stipulated as "do not pass through the sieve."

The series of operations described above can be carried out completely automatically in accordance with a program preset in the control device 4 as described above. Then, the control device 4 subtracts the tare weight of each sieve 8 obtained in advance from the weighing data finally obtained as described above to obtain the weight of each sample according to the particle size, and processes the data. Then, desired data such as a ratio (% by weight) of each particle size to all samples and a coarse particle ratio are obtained by calculation, and displayed or printed out as necessary.

As described above, according to the above apparatus, the sieving test work, which has conventionally been performed by relying on the manual work of the worker, can be fully automated, thereby sufficiently improving work efficiency and saving labor. be able to. The supporting arm 2 and the measuring arm 3 in the above device may be any one as long as each sieve 8 can be slightly lifted and supported as it is at the time of weighing, and the shaker 1 and the sieve 8 in this device are It can be diverted from those that have been widely adopted. Therefore, this device requires a high-performance robot hand to perform the operation of transferring the sieve between the shaker and the weighing machine, and further, a special shaker by sonic vibration and a special sieve therefor are required. This is a significant cost advantage over the conventional measuring instruments that need to be used. In addition, this device directly measures each of the sieves 8 to be measured, and since the load cell 37 is not subject to vibration, it is possible to use the highly sensitive and highly accurate load cell 37. Therefore, it is possible to sufficiently improve the measurement accuracy, and moreover, it is possible to reliably determine whether or not the sieving prior to weighing is sufficiently performed. Is particularly suitable for conducting a sand sieving test as.

It should be noted that the present invention is not limited to the above-described embodiment, and the configuration of each part, such as the form of the support arm 2 and the measurement arm 3, the mechanism for moving them up and down, and the mechanism for expanding and contracting them, are appropriately designed. Changes can be made. In addition, although five sieves are used in order to screen the sand as the fine aggregate in five stages in the above-mentioned examples, the present invention can be adopted not only for sand but also for other powders. It goes without saying that the number may be increased or decreased as necessary.

[0033]

As described in detail above, the invention according to claim 1
The method of the invention of (1) separates all the sieves above the sieve to be measured from the sieve to be measured by lifting and supporting the sieve directly above the sieve to be measured, and then lifting the sieve to be measured alone. Since the weight is measured separately from the upper and lower sieves by supporting it, the sieve to be measured can be easily and reliably separated from other sieves, and therefore the weight of each sieve can be directly and highly It is possible to weigh accurately and efficiently.

In the apparatus according to the second aspect of the present invention, a supporting arm and a measuring arm are provided on the side of the shaker so as to be movable up and down and extend and contract, and the supporting arm and the measuring arm serve as a sieve for measuring the object to be measured. After separating from the sieving machine and shaker, weigh individually and directly by the load cell incorporated in the measuring arm, and
Since it was equipped with a control device for controlling the operation of the support arm and the measurement arm and managing the measurement data, it was possible to realize a complete automation of a series of operations, and the configuration was simple and inexpensive, and it was excellent. It is possible to obtain the measurement accuracy, and it is suitable to be adopted for carrying out the above method.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a sieving measurement apparatus that is an embodiment of the present invention.

FIG. 2 is a plan view of the device.

FIG. 3 is a rear view of the same device.

FIG. 4 is a partially enlarged cross-sectional view of a sieve used in the same device.

FIG. 5 is a diagram for explaining a work procedure of a sieving test by the apparatus.

FIG. 6 is a diagram for similarly explaining a work procedure.

[Explanation of symbols]

 1 Shaker 2 Support arm 3 Measuring arm 4 Control device 8 (8a-8e) Sieve 37 Load cell.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Kimura, Inventor Takashi Kimura, 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toji Technical Center (72) Inventor Tamura Shin Showa, Kanazawa-ku, Yokohama 3174-cho Ishikawajima Construction Machinery Co., Ltd.

Claims (2)

[Claims] 1. A small grain size is obtained by stacking a plurality of sieves having different mesh openings one on top of the other with the meshes having a larger mesh size upwards, throwing the powder into the uppermost sieve and shaking the sieves. It is a method to determine the weight of each particle size by sequentially measuring the weight of each sieve after sieving by sequentially dropping the items on the lower sieve.
By lifting and supporting the sieve directly above the sieve to be measured, all the sieves above the sieve to be measured are lifted together and separated from the sieve to be measured, and then the sieve to be measured is lifted alone. A sieving measurement method characterized in that the weight is measured by separating it from the upper and lower sieves by supporting it. 2. An apparatus for carrying out the method according to claim 1, wherein the powder put into the uppermost sieve by shaking a plurality of sieves mounted in a vertically stacked state. A shaker for sieving the body, and a shaker that can move up and down on the side of the shaker and is expandable and contractable on the shaker side, and the tip of the shaker lifts and supports the sieve directly above the sieve to be weighed. And a support arm for lowering the support arm, which is vertically movable below the support arm and is expandable and contractable on the shaker side. The tip of the support arm lifts and supports the sieve to be weighed, and the load cell is installed at the tip. A measurement arm for measuring the weight of the sieve, and a control device for controlling the operation of the support arm and the measurement arm and managing the measurement data. A sieving measuring device characterized in that