JPS62238421A - Apparatus for detecting weight of particulate material - Google Patents

Abstract

PURPOSE:To perform correct stock control by making it possible to detect the wt. of a piled-up particulate material with high accuracy, by acting the pressure from the particulate material on a pressure detector and operating the total wt. of the particulate material on the basis of detected pressure. CONSTITUTION:The areas of the regions 21-2n of the ground 1 are preliminarily stored in the operational controller 5a of an operation part 5. The pressure of each region 2i detected by each of the pressure sensors 31-3n arranged corresponding to the regions 21-2n is introduced and the pressure introduced with respect to each region is multiplied by the stored area of said region and all of products obtained are added. The value obtained by multiplying the added value by a predetermined constant becomes the total wt. of a piled-up particulate material 4 and this wt. is displayed on a display device 5b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a weight detection device for powder and granular material that detects the weight of a pile of powder and granular material, such as coal, cement, grain, and the like.

[Conventional technology]

When storing a large amount of powder or granules, these powders or granules are often stored in piles outdoors or in a warehouse.

For example, in the steel industry, raw materials such as iron ore, coal,
Limestone and the like are transported in the form of powder and granules by transportation means such as ships, and then unloaded and stored in piles directly on the ground of stockyards, and are transferred from this pile to blast furnaces etc. by conveyors etc. as necessary. This storage method is applicable not only to the steel industry, but also to the storage of chemical materials and products in the chemical industry.
It is also used in many areas such as grain storage in the food industry.

Incidentally, it is necessary to manage the inventory of such piled-up powder and granular materials in exactly the same way as with ordinary articles.

The conventional inventory management described above, that is, grasping the current weight of the piled granules, is based on the difference between the weight of the granules brought in to be piled up and the weight of the granules carried out from the stored pile. This was done by calculating . For example, if we consider iron ore carried by a ship to be transferred to a stockyard using a crane and piled up in a pile, and then transported from this pile to a hopper by conveyor as necessary, the height of the ship's water line or the need for the crane to be Find out the weight of the piled iron ore using the weight measuring means installed on the conveyor, know the weight carried out by the weight measuring means provided on the conveyor, and subtract the latter weight from the former weight to determine the weight of the iron ore currently piled up. A method was used to determine the weight of the

In addition to such a method, a method of actually visually observing a pile of powder and granules and guessing the approximate weight by intuition has also been implemented.

[Problem that the invention seeks to solve]

By the way, measurement using the above-mentioned weight measuring means cannot avoid a considerable degree of error, and therefore it is impossible to carry out accurate inventory management. In other words, even if the measurement error caused by these weight measuring means is on the order of a few percent, each time the powder or granular material is carried in and out, the error will be accumulated each time, and as a result, in terms of inventory management, the amount of Even though there should be a pile of powder and granules,
In some cases, there is no granular material at the site, or conversely, even though the granular material is listed as O in terms of inventory management, in reality, the granular material is piled up.

As described above, it is extremely difficult to grasp the current total weight of the piled up powder and granular materials using the above-mentioned weight measuring means, and even more so, the error in visual estimation is too large to be used as data for inventory management. could not.

The present invention has been made in view of the above circumstances, and its purpose is to solve the above-mentioned conventional problems, to be able to detect the weight of piled up powder and granular materials with high accuracy, and to detect the correct weight. An object of the present invention is to provide a weight detection device for powder and granular materials that can perform inventory management.

[Means for solving problems]

In order to achieve the above object, the present invention arranges one or more pressure detectors at predetermined positions on a surface on which powder and granules are piled up so that the pressure from the powder and granules acts, The present invention is characterized in that the total weight of the powder or granular material is calculated by the calculation unit based on the pressure detected by the detector.

[Effect]

The pressure of the granular material detected by the pressure detector is input to the calculation section. The calculation unit calculates the total weight of the pile based on the input pressure. The calculation in the calculation unit is performed depending on the combination of the type of powder and granules, the shape of the pile of powder and granules, the arrangement of the pressure detector on the surface on which the powder and granules are piled up, etc.
This is performed according to a predetermined calculation method.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a perspective view of a powder weight detection device according to a first embodiment of the present invention. In the figure, 1 indicates the surface on which the powder and granules are piled up. Surface 1 is a concrete floor surface or ground surface in the field or in a warehouse. In the following explanation, these will be represented by the ground. 2I to 2o surrounded by broken lines are assumed areas that divide the entire portion of the ground 1 where the powder and granular materials are to be piled up. The divisions for forming these regions are arbitrary, and therefore each region 2. ~2. ．． each has an arbitrary area. 3. ~37 are each area 2. ~2. ．． One pressure sensor is placed in each area. These pressure sensors3. ~3
As long as it has a high rating, it can be any type of material, but it is preferable to use the
Preferably, the pressure sensor proposed by No. 940 is used.

4 shows powder and granules piled up in an arbitrary shape on the ground 1.

5 is each pressure sensor 3. ~3. ．． This is an arithmetic unit connected to. The calculation unit 5 includes a control/calculation unit 5a configured using a microcomputer and a display 5b.

Next, the operation of this embodiment will be explained with reference to FIG. FIG. 2 is a sectional view taken along line nm shown in FIG.

In FIG. 2, the same parts as those shown in FIG. 1 are given the same reference numerals. Now, consider the columnar part 5 shown by the broken line above the pressure sensor 3 disposed in the center of the granular material 4.

Considering that the powder exists only in this columnar part 5, the pressure sensor 3. The pressure acting on is a certain value P that is proportional to the weight of the powder. becomes. However, as a result of various experiments, the present inventors have found that when the granular material 4 is piled up, the pressure acting on the pressure sensor 3k is the pressure P when the granular material exists only in the columnar part 5. , does not necessarily match,
It was found that other pressures were exhibited. The details will be described later in the explanation of the fourth embodiment of the present invention, but this phenomenon occurs because the powder or granules are in a state where they are leaning on the surrounding powder or granules as shown by the arrow p, or vice versa. considered to be a thing.

From the above, for example, when considering the weight of the powder in the columnar part above area 2, if it is not a powder but a fluid, the weight will be determined by the value detected by the pressure sensor 3 in area 2. area A
However, in the case of piled-up powder and granular material, the value P5, which is the product of the detected pressure Pk of the pressure sensor 3 by the area Ak of the two areas, is not necessarily the value above the area 2. It can be seen that this does not indicate the weight of the powder in the columnar part.

However, as a result of further experiments and studies, the inventors found that in a pile of powder and granules, the product of the detection value of the pressure sensor and the area of the area is the powder at the top of the area. It has been found that even if the weight is not indicated, the product of the detected pressure value and the area for each region is the total weight of the piled up powder and granules. This means that the pressure increases and decreases in the twisted and untwisted parts of the granular material cancel each other out, and as a result, when the products are added together, the true value of the granular material on each area is It is thought that the error in weight is also due to sentence cancellation.

In accordance with the results of the experiments and studies described above, in this embodiment, each area 21 to
2) is stored in advance, and each pressure sensor 3I-3 is
Introduce the pressure in each region detected by 7. Then, for each region, multiply the introduced pressure by the stored area of that region and add all the resulting products.

The value obtained by multiplying this added value by a predetermined constant becomes the total weight of the piled powder and granular material. This weight is displayed on the display 5b.

In this way, in this example, the entire area where the powder and granular material is to be piled up is divided into arbitrary areas, a pressure sensor is provided for each area, and the calculation unit calculates the product of the detected value of the pressure sensor and the area of the area. is added for each region and multiplied by a predetermined coefficient, so the total weight of the piled up powder and granular material can be detected accurately at all times, and this can be determined based on the condition of the piled up material. It is possible even in the state. The smaller the area of each region, the higher the detection accuracy can be.
Calculation becomes easier if the area of each region is set equal.

By the way, in the first embodiment described above, a means was proposed which can detect the total weight of any pile of powder or granules, regardless of the shape of the pile. In contrast, the means proposed in the second to fifth embodiments described below are as follows:
This is a weight detection means when the shape of a pile of powder or granular material is a specific shape.

FIG. 3 is a perspective view of a powder weight detection device according to a second embodiment of the present invention. Generally, one method that is often used when piling up powder and granular materials is to drop the powder and granular materials directly below from a certain high position. The shape of the pile of powder and granular material obtained by this method is conical. The weight detecting device of this embodiment is used when piling up powder and granules in a conical shape as described above.

In the figure, 1 indicates the ground, and D indicates the falling point of the powder.

If the powder or granular material continues to fall straight down from the point of fall,
The shape of the powder piled up on the ground 1 is as shown in the figure.
It has a conical shape with its axis centered on the perpendicular line drawn down from the point of fall, indicated by a dashed line. The powder and granules piled up in a conical shape as described above are indicated by the reference numeral 4A. 2A, ~2A, 1 surrounded by dashed lines
is the assumed area on the ground 1. These regions 2A, -2A are divided concentrically with respect to the conical axis of the powder and granular material 4A, and have a ring shape. 3A, ~3A7
is a pressure sensor placed in each of the areas 2A1 to 2Afi. 5 is the same arithmetic unit as shown in FIG.

Next, the operation of this embodiment will be explained. Now, looking at the area 2Al+, this area has a ring shape centered on the conical axis. Therefore, if the width of the ring is considerably small, it can be considered that the pressure exerted by the granular material 4A is approximately equal at any location in this region 2Ak. Therefore, one pressure sensor 3A is arranged at an arbitrary location in the area 2Ab, and the detected pressure P 3
Ak and area A of area 2Ak! A1), the product (P3Ak-A2Ak) corresponds to the product of the pressure and area of each region in the first embodiment. Therefore, for the reason stated in the first embodiment, in this embodiment as well, each area 2 A + to
By multiplying the area by the pressure obtained by the pressure sensors 3A and 3A for every 2A, adding these products together, and multiplying this by a predetermined coefficient, the total weight of the powder and granular material 4A can be calculated. can be obtained.

The above explanation is for detecting the total weight of the piled up powder and granular material 4A when the powder and granular material is dropped from the WD onto the horizontal ground 1. This detection means essentially remains unchanged even if the ground is sloped. Below, a means for detecting the weight of powder and granular material piled up on a sloped ground will be explained.

FIG. 4(a) is a perspective view of powder and granules piled up on a slope;
FIG. 4(b) is a diagram of the state shown in FIG. 4(a).

In each figure, 1' indicates a ground surface having an inclination of angle ψ, and 4A' indicates a pile of granular material, which has a distorted cone shape.

In the figure, only pressure sensor 3Ak is shown, and illustration of the calculation section is also omitted.

Here, the pressure detected by the pressure sensor 3Ak is P3
Ak, assuming that the coefficient of friction between the powder and the ground 1' is 0,
The pressure caused by the granular material is the combined pressure of both PsAh”
(=P:+As+1+ko''). Also, on the sloped ground 1', there is a region exhibiting a pressure almost equal to the pressure P3Ak (the region to which the pressure sensor 3A belongs).
If the area of is ・A, then its projected area on the horizontal plane A
, ' becomes A6 ・cos ψ. Therefore, the product of area and pressure in the area of the horizontal plane corresponding to the area is Am
'·P, □ ' is expressed by the following equation.

Ak ′°P, ^w ′ =Ak′CO3ψ“P 3
Ak1+ko”・・・・・・(1) In equation (1), the value A +=, k o is known, and the value P
Since 3Ak is the detected value of pressure sensor 3A, in the end,
By calculating the product obtained by the above formula for each region, finding the sum of these products and multiplying by a predetermined coefficient, it is possible to know the total weight of the powder and granular material 4A' piled up on the sloping ground 1'. can.

The method for detecting the total weight of powder and granules piled up on a slope as described above can be applied to the first embodiment described above, and also to the other embodiments described below. Applicable.

As described above, in this example, when powder and granules are piled up in a conical shape, a ring-shaped area is assumed to be centered around the axis of the cone, a pressure sensor is provided for each area, and the calculation unit The product of the detected value of the pressure sensor and the area of that region is added for each region, and this is multiplied by a predetermined coefficient, so the total weight of the piled up powder and granules can be detected accurately at all times. be able to. Then, the smaller the width of the ring in each area, the higher the detection accuracy can be. Furthermore, compared to the previous embodiment, the number of pressure sensors can be dramatically reduced, and the device can be constructed at low cost.

FIG. 5 is a perspective view of a powder weight detection device according to a third embodiment of the present invention. Earlier, as one of the methods for piling up powder and granules, we described a method in which the powder and granules are dropped from a predetermined height and piled up in a conical shape, but there are other methods as well, such as: There is. That is, as shown in Fig. 5, the powder is dropped from a high position D', and when the powder reaches a predetermined height, the position D' is sequentially moved in parallel in the direction of the arrow. . According to this heaping method, the shape of the piled powder and granular material (indicated by reference numeral 4B) is such that the center part is a rectangular triangular prism shape, and both ends thereof are semiconical shapes. The weight detection device of this embodiment detects the weight of the powder particles piled up in this manner. The means for detecting the weight of the powder in the semi-conical portion is the same as that described in the second embodiment, and in the description of this embodiment, the detection of the weight of the powder in the triangular prism portion will be described.

In the figure, 2B, ~2B, surrounded by broken lines are the areas assumed on the ground 1 where the powder and granular materials 4B are piled up, 3B+*, 3B
z~3B, l is each area 2Bt~2B.

Pressure sensors 3Bz to 3B17 are placed on the ground 1 corresponding to the upper ridgeline of the triangular prism. Looking at the above-mentioned triangular prism part, the reason why the pressure exerted by the granular material 4B on the bottom surface is almost equal is as follows.
It is clear that this is a longitudinal surface along the ridgeline of the triangular prism. Therefore, in the case of this embodiment, areas 2Bt to 2B
, the end is assumed to be an elongated strip-shaped region in the length direction.

On the other hand, one pressure sensor 3B+m to 3B, 1 is arranged in each of these regions 2B1 to 2B, but the arrangement position is close to the starting position of the pile of powder and granular material 4B and close to the starting position of the powder and granular material 4B. A position far from the extraction position is selected. or,
Pressure sensors 3Bz to 3B+, are located at positions corresponding to the upper ridgeline of the triangular prism (area 2B).

(inside) are arranged at equal intervals along the ridgeline.

Among these pressure sensors 3B, . . . -3Bl, the pressure sensor 3B+ is located on the same line as the pressure sensors 3B2 to 3B, . Note that no pressure sensor is arranged on the other side of the bottom surface of the triangular prism, which is considered to be symmetrical with the one side. Further, in FIG. 5, illustration of the calculation section is omitted.

Next, the operation of this embodiment will be explained. As in the previous embodiment, in this embodiment as well, each area 2 B +
2B, calculate the product of the area of the part where the powder exists and the pressure, add these products, multiply this by a predetermined coefficient, and double the obtained value. As a result, the total weight of the granular material 4B in the triangular prism portion is calculated. By adding the weight of the semi-conical portion to this value, the total weight of the piled up granular material 4B can be obtained.

In the above calculation, in order to know the area of the part where the granular material exists in each region 2B, to 2B+, it is necessary to know the length of the part where the granular material exists in the longitudinal direction of the triangular prism of those regions. Pressure sensors 3B1) to 3B5 are used to determine the above length.

That is, considering the area 2B, the width d of the area 2B.

is known, and the dimension d2 between the midpoints of adjacent pressure sensors 3BII to 3B+- is also known. Therefore, if it is known how many pressure sensors among the pressure sensors 3Bz to 3BIfi are detecting pressure,
The area of the region 28 is the product of the known values d, d, and the number of detected objects.

The effects of this embodiment are also exactly the same as those of the second embodiment.

FIG. 6 is a perspective view of a powder weight detection device according to a fourth embodiment of the present invention. In the figure, 4A is the powder piled up in a conical shape as in the second embodiment, and 3A is the point where the perpendicular drawn from the apex of the cone intersects with the ground 1 (the center of the conical circle). pressure sensor located at position 5'
is an arithmetic unit, 5a'' is its arithmetic/controller, and 5b'' is a display.

Next, the principle of the particle weight detection means of this embodiment will be explained. Now, R: Radius of the base of the cone H: Height of the cone e: Angle of repose of a pile of a certain powder (equal to the internal friction angle, determined by the type of powder) T: A certain powder Assuming the apparent specific gravity of the body (average specific gravity), the volume of the cone V
is ■=□πR” H・・・・・・・・・・・・(2) H/
R=tan61 Since (3) is satisfied, substituting equation (3) into (2) 2 gives the following equation. Therefore, the total shape 1w of the granular material 4A is as follows. In equation (5),
Once the type of powder is determined, the apparent specific gravity T and angle of repose θ
Since the tangent tan θ of is known, the weight W of the granular material 4A can be obtained by knowing the height H of the conical shape. Hereinafter, a method for determining the height H of the conical shape of the piled-up powder and granular material 4A will be explained.

As a result of various experiments and studies, the present inventors have found that the pressure distribution at the bottom of a pile of powder and granules exhibits an extremely unique pattern, and that this pattern differs depending on the type of powder and granules. I found it. This will be described based on the results of experiments conducted by the inventors.

Figures 7(a) and fb) show the experimental results when millet weighing Mk 3 kg is piled up in a conical shape. (
'b) is a characteristic diagram of pressure distribution and friction distribution. 7th
In figure (a), the horizontal axis is the radial distance R (
am), and the vertical axis is the height H (ms).

4A indicates the top of the piled millet, and ■ indicates its ridgeline. In addition, in Fig. 7 fb), the horizontal axis shows the above distance R (++
n), pressure and frictional force (Pascal) are plotted on the vertical axis. ■ indicates a pressure curve, and ■ indicates a friction force curve. In addition,
In each figure, the curve to the left of the center, ■.

Only part of ■ and ■ is shown, and other illustrations are omitted.

Looking at the distribution of the pressure curve ■ in Figure 7 (bl), the pressure PA3 at the center of the bottom (corresponding to vertex 4A) is the same as that of the surrounding areas, even though the height of the cone in that area is the highest. The pressure increases linearly as it moves away from the center of the bottom surface, eventually reaches the maximum pressure PAH, and then decreases linearly as it moves toward the edge of the bottom surface.Such a unique pressure distribution As mentioned in the explanation of the first example, this seems to be a phenomenon that occurs because the millet in the center is more heavily affected by the surrounding millet.And the state of the pressure distribution is caused by the weight of the millet. Even if the pressure is different, P0, P
It was confirmed that only the value of AH and the position of occurrence of the value PAN change, and the pattern itself does not change.

Figure 8 (al) and (b) show the experimental results when silica sand weighing 12 kg was piled up in a conical shape.
Portions corresponding to FIGS. (a) and (b) are given the same reference numerals. The same can be said for this pile of silica sand as for the pile of millet.

Based on the above experimental results, the present inventors conducted various studies and found that the following law holds true.

In other words, if we draw a perpendicular line from the apex of powder and granules piled up in a conical shape to the bottom surface and consider a unit column centered on this perpendicular line, the pressure PA ( A law that states that the ratio between the pressure PAs (corresponding to the pressure PAs in the above experiment) and the pressure P,' that would be exerted on the bottom surface when the unit column is taken out individually is a constant value C determined by the type of powder or granule material. It is. This law can be expressed as follows: PA/P^'-C...<61. From the experimental results, the constant C is approximately 0.63 for millet and approximately 0.40 for silica sand.

In equation (6), the pressure PA' is the weight of the unit column multiplied by a predetermined coefficient. Since the weight of a unit column is the value obtained by multiplying the apparent specific gravity T of the granular material by the height H of the conical shape, if the above predetermined coefficient is C', then (6
) can be expressed as follows.

From equation (7) However, CA=CC''.

Therefore, returning to the above equation (5) again and substituting equation (8) into equation (5), the following is obtained. In equation (9), the values CA, T, and tanθ are known values determined by the type of powder or granular material, and only the pressure PA is an unknown value.

In this embodiment, based on the above research results, a pressure sensor 3A is placed on the ground 1 corresponding to the center of the bottom surface of the granular material 4A in order to obtain the pressure P in (9) 2 above. Then, the calculation section 5' inputs the detected pressure PA of the pressure sensor 3A, and calculates the above equation (9). Thereby, the total weight of the granular material 4A can be known.

As described above, in this embodiment, when powder and granules are piled up in a conical shape, a pressure sensor is provided on the ground corresponding to the apex of the cone, and the detected value of this pressure sensor, the type of powder and granules, and the pile are measured. Since the predetermined calculation is performed based on the shape of the powder, the total weight of the piled up powder and granules can be detected accurately at all times. Also, the pressure sensor installed is 1
Since only one is required, the device can be constructed simply and at low cost.

FIG. 9 is a perspective view of a powder weight detection device according to a fifth embodiment of the present invention. In the figure, 4B is the same triangular prism as shown in FIG. 5, and 3BII to 3B+ are the same pressure sensors as shown in FIG.

Note that illustration of the calculation unit and the hemiconical heaped portion at the end of the triangular prism body are omitted.

Now, consider, for example, a triangular prism body having a unit width l and including the pressure sensor 3B+k. As a result of experiments on millet and silica sand, it was found that such a triangular prism was also found in Fig. 7 (bl, 8
It was found that a pressure distribution similar to the characteristics shown in Figure (b) appeared. Therefore, L Length of the base of two triangular prisms H Height of two triangular prisms θ: Angle of repose of a pile of powder and granules T: Apparent specific gravity of a certain powder and granules V Volume of a triangular prism with unit width l W : Weight P of powder and granular material constituting a triangular prism of unit width l, :
Assuming the pressure detected by the pressure sensor 3Blk, tanθ CB2 ・T−tanθ ・・・・・・・・・・・・ aυ as in the case of the piled up granular material 4A in the fourth embodiment . However, the value CB is +8+ (corresponds to the value cA in formula 91, and is a value specified when a certain powder or granular material is piled up in a triangular prism shape.

In this way, the powder particle weight W of the triangular prism of unit width l can be determined, so if the pressure sensor 3B+k is arranged at the same position as described in the third embodiment, the calculation section can calculate the The powder weight W is calculated by calculating the powder weight W, and the pressure sensors 3B+t to 3B1 are
By checking the number of pressure detected out of 7 and multiplying by that number, it is possible to know the weight of the powder 4B in the triangular prism part. Then, by adding the weight of the granular material in the semi-conical portion to this value, the total weight of the granular material 4B can be determined.

Note that it is not necessary to use a specific pressure sensor 3B□ to detect the pressure P in formula 09, and the maximum detected value among the detected values of the pressure sensors 3B, ~3BIfi is used as the pressure P.
It may also be used as i.

As described above, in this embodiment, when powder and granules are piled up in the shape of a triangular prism, pressure sensors are provided on the ground at the bottom of the triangular prism along the ridgeline of the triangular prism, and the number of pressures detected by these pressure sensors, Since a predetermined calculation is performed based on the detected pressure value of one of them, the type of powder and granular material, and the shape of the pile, the total weight of the pile of powder and granular materials can be detected accurately at all times. can. Furthermore, the number of pressure sensors can be reduced, and the device can be configured simply and at low cost.

〔Effect of the invention〕

As described above, in this embodiment, when powder and granular materials are piled up, one or more pressure sensors are provided at predetermined positions on the bottom of the pile, and the calculation unit performs a predetermined calculation based on the detected values. As a result, the total weight of the piled up powder and granular materials can be accurately detected at all times, and inventory management can therefore be carried out correctly.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a weight detection device according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line nn in FIG. 1, and FIG. 3 is a second embodiment of the present invention. A perspective view of a weight detection device according to
4(a) and 4(b) are perspective views and line diagrams of the weight detection device shown in FIG. 3 when the ground is a slope, and FIGS. 5 and 6 are respectively the third and fourth embodiments of the present invention. Perspective views of the weight detection device according to the embodiment, FIGS. 7(al), (b), and 8
Figures (a) and (b) are graphs showing the shape of a pile of powder and granular material and pressure distribution, respectively, and Figure 9 is a perspective view of a weight detection device according to a fifth embodiment of the present invention. 1...ground, 2. ~2. , 2A, ~2A, 1.
γL~2B,... area, 3I~3. ,．． 3A,
3At~3A,,,3B+~3B,l,3B+t~3B
,,,...Pressure sensor, 4, 4A, 4B...
...Powder, 5.5'...Calculation section. Figure 1 2 da Figure 2 Figure 5 Figure 6 Figure 5' Figure 7 tσ Figure 8 tσ

Claims (4)

[Claims] (1) One or more pressure detectors that are placed at predetermined positions on the surface on which powder and granular materials are piled up and detect the pressure received from the powder and granular materials, and perform predetermined calculations based on the detected values of the pressure detectors. What is claimed is: 1. A weight detection device for powder or granular material, comprising: (2) In claim (1), the pressure detector is arranged in a region formed by arbitrarily dividing the surface into a plurality of regions.
A weight detection device for powder and granular material, characterized in that the weight detection device is arranged one after the other. (3) The weight detecting device for powder or granular material according to claim (1), wherein one pressure detector is arranged for each region showing the same pressure on the surface. (4) In claim (1), the pressure detector is arranged only at a location corresponding to the top of the pile of the powder or granule on the surface. Weight detection device.