JPS6191520A - Weighing/filling control method and apparatus - Google Patents

Abstract

PURPOSE:To enable a high-speed filling at a high accuracy, by calculating the drop impact value from second to second detecting the weighing increment speed in a weighing basket at a fixed cycle to cut off the dumping when the net dump amount reaches a set value. CONSTITUTION:When a filling material I exceeding a fixed amount is dumped into a weighing basket 2 from a feeding hopper 1 reaches a forecast net dump amount value, the dumping is cut off with a controller 5 to measure the filling material I with a weighing device 3 and then, a suction nozzle 4 is operated to suck up the filling material I' by an amount exceeding the fixed amount by inserting into the basket 2. Moreover, the filling material I in the basket 2 during the operation of the suction nozzle 4 is weighed and the operation of the suction nozzle 4 is halted with a controller 5 when it decreases to the fixed amount and finally, the filling material I weighed in the backet 2 is discharged to a container II to fill. The container II filled is moved and an empty container II below the basket 2 is sent in. This can improve the filling yields significantly to enable a high speed and a higher accuracy of the total filling cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a high-speed, high-speed, and high-speed method for measuring a fixed amount of powder, granule pellets, lumps, liquid, etc. of detergent, etc., and filling it into a container.
The present invention relates to a metering and filling control method for filling with high precision and an apparatus therefor.

[Prior art] Generally, packaged products are often sold with the indicated weight of the contents, but if there is an excess or deficiency in the quantity of the contents, the lack of indicated weight is more of a problem in actual transactions. From experience, as a seller, I always check the safety level by filling the product to a weight higher than the indicated weight, so this packaging trend causes an extremely large economic loss.

Therefore, there is a demand for highly accurate weighing and high-speed weighing fabrics that minimize variations in total weight during packaging.

An example of a conventional method of this type is a loading method in which powder or granular material 1, for example, detergent, is first supplied in an amount less than the fixed amount into the space to be measured, and then the shortfall in the set meal is supplied in small amounts to replenish the amount. had been adopted. In other words, after filling a container with the object to be weighed (filling material), the weight (usually including the container) is measured using a weight checker, and the amount to be added is periodically added to the weight to avoid underweight items. A method is used to manage the filling weight while setting the

[Problems to be solved by the present invention]

However, the specified weighing (filling) amount (quantity + filling amount) is fixed until the filling amount is corrected, and there is a general tendency to overestimate the filling amount to avoid underweight items. Even if the fluidity, bulk specific gravity, etc. of the material (for example, powder or granular material) are stable and the amount of filling is small, the amount of filling is increased to ensure safety, and the amount of filling increases by that amount. Not only is there an accuracy problem in that the yield is degraded, but this micro-replenishment method not only requires slowing down the feeding speed for high-precision weighing, but also takes a long time to weigh, making it impractical for filling processing operations. do not have.

For this reason, attempts have been made to introduce a large amount of material in a short period of time and remove the surplus, but even if a large amount of material is added in a short period of time, if there is a large amount of error in the amount of material, it will take time to balance the end point. , high-speed filling is not possible. Errors during this large amount of charging include the impact of the fall, the amount of air passing from the charging gate to the powder surface, and the amount of falling during the gate cutoff time.The latter two are due to low head,
Although it can be handled by high-speed interruption, the falling @ impact increases as the falling mass velocity increases, and changes in the bulk specific gravity and fluidity of the powder or granule material will cause variations in the impact value, offset (deviation),
The variation error also increases. For this reason, there is a method known as head correction, which feeds back the difference between the shutoff setting value of the previous filling and the end point and corrects it, but even this method is basically an offset correction, and it cannot absorb the variation error and has accuracy problems. .

In order to eliminate these conventional drawbacks, the present invention enables high-accuracy, high-volume injection in a short period of time, and in order to reduce the burden on the end-point barage, the drop impact value at that point is calculated moment by moment during large-volume injection in real time, and the net input amount is calculated. This is a useful method that enables high-speed, high-precision filling by predictive control that predicts and automatically corrects the feeding drop error by predicting and cutting off the feeding when the predicted value reaches the set value. It is an object of the present invention to provide a device that can effectively implement the method in a simple and inexpensive form. Another object of the present invention is to shorten the weighing time by constant speed input without slowing down the input speed, and to speed up one cycle without being affected by fluctuations in drop impact value (velocity, resistance with air). It is an object of the present invention to provide a weighing and filling method and an apparatus for the same that make it possible to improve weighing accuracy.

[Means for solving problems]

The present invention provides for increasing the amount of material in the weighing basket in weighing and filling control in which a quantity of filling exceeding the fixed amount to be filled into the container is put into the measuring basket, and then the filling amount exceeding the fixed amount is removed and filling the container. The method is characterized in that the velocity is detected at a constant cycle, the falling impact value is calculated moment by moment, the net amount of input is predicted, and the input is cut off when the set value reaches the predicted value, and then the excess amount of input is eliminated. A metering and filling control method and apparatus thereof.

〔Example〕

A preferred embodiment of the present invention will be described below based on the drawings. In FIG. When the predicted value is reached, the control device 5 turns on and off the filling, the metering device 3 measures the filling material 3, the suction nozzle 4 is activated, and then the suction nozzle 4 inserted into the measuring basket 2 exceeds the fixed amount. A quantity of filling I' is aspirated. Further, the suction nozzle 4 weighs the filling I in the measuring basket 2 while it is in operation, and when the amount has decreased to a fixed amount, the operation of the suction nozzle 4 is stopped by the control device 5, and finally the measured filling in the basket 2 is measured. Discharge and fill the material ■ into the container ■. The filled container (2) is moved, and an empty container (2) is sent below the measuring basket 2 in preparation for the next filling.

That is, as shown in FIG. 2, the filling material (1) is transferred by the supply belt conveyor 6, supplied to the supply hopper 1, and stored in the supply hopper 1.

At this time, the amount of supply from the supply belt conveyor 6 to the supply hopper 1 is measured by a level gauge 7 and kept at a constant level. An opening/closing shutter 8 is attached to the opening at the lower end of the supply popper 1.

This opening/closing shutter 8 is opened/closed when the shutter drive solenoid 9 is given an opening or closing command from the control device 5, and the opening/closing shutter 8 of the supply hopper is opened, and the falling filling material is transported to the supply hopper 1. However, when the predicted filling value reaches the filling set value during filling, the opening/closing shutter 8 closes and the filling is interrupted, and the measuring packet provided in the measuring basket 2 It is weighed by a device 6, for example a load cell. A suction nozzle 4 is inserted into the measuring basket 2, a discharge pipe 10 is connected to the suction nozzle 4, and a return device 11 is connected to the discharge pipe 10.
are connected to each other, and a suction device 12 is attached to this return device 11. Further, a valve 13 is installed in the middle of the discharge pipe 10. This valve 16 is for opening and closing a hole 10a bored in the discharge pipe 10.
When the window 13a of the valve 13 matches, the air flows out to the outside and the suction nozzle 4 does not operate, and when the hole 10a is closed, the suction nozzle 4 operates. The opening and closing of the hole 10a by the valve 13 is performed by the control device 5 by operating the nozzle drive solenoid 13'.

The suction nozzle 4 has a double pipe structure, in which outside air is introduced from the surrounding gap, and the introduced outside air and the filling material I are sucked through the central gap into the discharge pipe 10 and discharged to the return device 11. Ru. This return device 11 includes a back filter 14
Only the air is sucked into the suction device 12 by this back filter 14, and the excess amount of the filling material 2' is stored in the chamber 15 in the return device 11. The return filling 1' stored in this chamber 15 is discharged to the supply hopper 1 again through the rotary valve 16.

A discharge gate 17 is attached to the lower end opening of the weighing packet 2, and a gate drive solenoid 18 is attached to this discharge gate 17, and this solenoid 18 is activated by a command from the control device 5 to open and close the discharge gate 17. The opening/closing of the discharge gate 17 is controlled by the control device 5 which has read the information from the weighing device 6 when the filling material (■) in the weighing packet 2 reaches a fixed amount due to suction of the filling material (■) by the suction nozzle 4. The valve 16 is operated to stop the suction operation, the gate drive solenoid 18 is then operated to open the discharge gate 17, and the control device 5 reads the information from the metering device B to determine whether all the filling material I has been discharged. The controller 5 then operates the gate drive solenoid 18 again to close the discharge gate 17. The filling material I discharged from the weighing packet 2 passes through the filling chute 19 and is filled into the empty container (2).

The control device 5 in the present invention detects the weight increase rate of the basket 2 in real time.

The high-speed A power converter predicts the falling impact value at that point and estimates the weight of the powder in the basket 2 by subtracting the predicted impact value from the weight indication value that includes the powder weight in the basket 2 and the impact value. 56 and a high-performance computer 54, for example, 1/10 in a short time of 1.5 seconds.
It becomes possible to obtain an accuracy of 0, and the subsequent suction and extraction process is performed.

In this case, as shown in FIG. 5, if the actual input amount is a natural fall, the variable fall impact value is amplified by a signal adder 51 and multiplied by an amplifier 52, and is expressed on the scale as -3. /
It is designed to follow this at a speed of 100 seconds.

In addition, in the case of the present invention, the falling impact value is measured in advance with the same weighing object as the filling (1) within the usage variation range of the physical properties of the filling, such as the falling speed, head, and physical properties of the filling, such as true specific gravity, bulk specific gravity, and shape. The accuracy is determined using an approximate correlation formula with the parameters, and the increase in weight of the weighing basket 20 of the actual device is detected at regular intervals in the first order.
The computer 54 programmed with the above correlation formula analyzes the drop impact value and estimates the true weight increase.

For example, in the case of detergent powder, a certain weight of measured powder is placed in a supply hopper closed with a partition plate.
Remove the partition plate and drop the powder into the hopper. The fallen powder hits an inclined plate (at a 45 degree angle) and flows downward.

At this time, read the weight on the spring scale.

The falling speed of the powder is calculated by measuring the time from when the partition plate is removed until the entire amount falls. The number of measurements was 5 times with the same falling mass velocity and the same head, and the head was 100.200.3
00mm falling mass velocity is 0.5.1.0.2.0゜2,
5 kVsec, but the measurement results showed head fluctuation (
100 to 300 mm) as an error factor, regression analysis of the falling mass velocity and impact value was performed using the following equation.

Regression equation Y-=A-x+c Granular detergent: bulk specific gravity 33 o gr/1: moisture 5.5%: average particle size 450μ A=0.4261. 0=-0,0336y=0.42
61 x+ (-0,0336)...Correlation coefficient 0.9
88 Y...Fall impact value (kq) A...Coefficient C...
Constant, )oWn...Weight indication value 0IW at the measurement point
n...Amount of increase in input weight per measurement interval o CWn
... Cumulative value of weight increase (amount of powder in the weighing basket) 01Fn ... Shows the drop impact value at the measurement point, and shows the analysis procedure: Wn at 0'pn and VVn at Tn-1
Find the difference of 1.

Find oIWn using the IWn calculation formula that expands the regression formula.ocW
OWn is estimated by adding up IWn to n-1.

Repeat the above until OCWn becomes equal to the input setting value.

When the formula for calculating CWn is expanded from the regression formula, from Figure 3, Wn -0Wn-1= iFn+ (WnWn-CWn
−1=(A−IWn10)+IWnWn−CWn −1
= IWn (A+1) + OIW = (W
n-0Wn-1-C)/(A+1), °, CW
n= ((Wn-CWn-1-C)/A+1)+0W
It becomes n-1. Accordingly, based on this calculation, when the predicted value CWn reaches the set loading weight CFW as shown in FIG. 4, the loading is interrupted and the subsequent suction extraction is performed.

The weighing device 6 uses an electrical weight detection sensor with a quick response speed, such as a load cell or a force balance, and includes a signal adder 51 and an amplifier 5 for amplifying the output of the weighing sensor.
The control mechanism includes a converter 56, which is an A/D converter that converts the signal into a digital signal via 2, and a computer 54 as an arithmetic command means. The computer 54 serving as the control means controls the operation of the weighing and filling device (opening/closing shutter 8 pulp 16, discharge gate 17, etc. shown in FIG. 2) by a control mechanism operated by commands from the detection signal of the detection means. Reference numeral 20 denotes initial constant setting means, which includes setting sections for, for example, measurement time, measurement settling time, discharge time, quantity, number of sample data, standard value, tolerance rate, and the like.

The computer 54 which performs the calculation means performs a new calculation using the data from the constant setting means 20 and the detected value from the detection means as input, and provides the result to the control means of the shutoff valve.

FIG. 4 shows a computer 54 equipped with each of the above-mentioned components.
This is a flowchart showing an example of a specific execution when the weighing analysis control device is applied to the weighing and filling device (Fig. 1). It is convenient to have a configuration.

As described above, the main part of the weighing control device is composed of a microcomputer, but its application is not limited to the weighing and filling device described above, but can be widely applied to devices that perform weighing management using a secondary control method. can do.

Note that the falling impact value is influenced by the falling mass velocity, head difference, and air resistance, but since many powders and granules have large air resistance, the mass velocity is the dominant factor.

Therefore, this mass velocity can be estimated by knowing the weight increase rate of the weighing basket, and since the weight increase rate can be obtained as a value that includes changes in the bulk specific gravity, fluidity, head, etc. of the powder, the powder characteristics can be estimated. It becomes possible to control without being affected greatly even by fluctuations.

The high-speed converter has a resolution of 12 bits and a conversion speed of about 25 to 100 microseconds, and the computer uses a system that combines a 16-bit microprocessor and an arithmetic processor and is driven by a 5 MHz clock. It is suitable if Furthermore, the weighing device 6 can be combined with an electrical weight detection sensor such as a wire strain gauge having a fast response speed. The response speed of this wire strain gauge is 0.0
If you use one for about 1 second, the suction and discharge speed will be 0.42
Since it is faster than seconds, it is possible to follow it well.

The weighing and filling method according to the present invention is used for weighing and filling not only powder and granular materials but also liquids, slurries, sand, granules, and other raw materials d') /<Sochi, which are dropped into a weighing machine that can continuously measure the weight. This is something that can be done.

〔Effect of the invention〕

In the present invention, more than a fixed amount is supplied from the supply hopper to the weighing packet, so it takes a little longer to dispense the large amount than the conventional method, but it eliminates the dispensing process for accurate weighing as in the conventional method. , there will be no errors in measurement accuracy due to inertia caused by falling during dispensing and the inability to control the filling while it is moving in the air, and even if a large quantity is injected in a short period of time, it will be controlled to absorb variation errors and the final point will be small with fewer errors in dosing. High-speed filling is possible because balancing does not take much time and reduces the burden.Moreover, the mass speed of the filling can be estimated by detecting the weight increase rate of the weighing basket, and this weight increase speed is dependent on the weight increase rate of the filling. bulk specific gravity,
Since it is taken as a value that includes changes in fluidity, head, etc., the characteristics of the filling material can be followed without being greatly affected by fluctuations, allowing highly accurate filling.

In addition, the device of the present invention can speed up weighing time and improve weighing accuracy at the same time, and can remove excess filling at high speed. By combining these, it is possible to further improve the weighing accuracy, and since it is possible to control the input error in large quantities within the range that is as small as possible, it is possible to expect a significant improvement in the filling yield. Enables high speed and high accuracy of the entire filling cycle.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the control principle of the present invention, Figure 2 is a schematic diagram of the main parts of the weighing control device, Figure 3 is a relationship diagram between weight indication values and measurement points, and Figure 4 is analysis and control. 70-Chart of the program, FIG. 5 is a graph in which changes in the input amount and changes in the drop impact value in the case of detergent are displayed as a relationship between time (T) and weight indication value (Wn). 1... Supply hopper, 2... Measuring basket, 6...
...Measuring device, 4...Suction nozzle, 5...Control device, 8...Opening/closing shutter, 17...Discharge gate, 5
DESCRIPTION OF SYMBOLS 1... Signal adder, 52... Amplifier, 53... Converter, 54... Computer, ■... Filler,
■...Container.

Claims (1)

[Scope of Claims] 1. In the weighing and filling control in which a quantity of filling that exceeds a fixed amount to be filled into a container is put into a weighing basket, a quantity of filling that exceeds the fixed amount is removed and filled into the container. The rate of increase in the weight in the basket is detected at regular intervals, the fall impact value is calculated moment by moment, and the net amount of input is predicted.When the predicted value reaches the set value, the input is cut off, and the excess amount of input is removed. A measuring and filling control method characterized by: 2. In order to predict the net input amount, it is recommended to use the falling impact value of the same weighed object, which has been measured in advance over a range of variations in physical properties such as falling speed, head, true specific gravity, bulk specific gravity, and shape of the weighed object. A metering and filling control method as claimed in claim 1. 3. To predict the net input amount, measure the weight increase of the weighing basket at regular intervals, and use a computer programmed with a correlation formula for the predicted drop impact value to solve the drop impact value and estimate the true weight increase. A measuring and filling control method according to claim 1 or 2, which is used for. 4. Any one of claims 1 to 3, wherein the net input amount is predicted by subtracting the predicted impact value from a weight indication value including the weight of the filling in the basket and the impact value. Metering and filling control method described in one section. 5. Using the falling impact value as an error factor, a regression analysis of the falling mass velocity and the impact value is performed using the regression formula Y=A・x+
C {However, Y...drop impact value, (kg) A...coefficient, C...constant,
5. The weighing and filling control method according to any one of claims 1 to 4, characterized in that the measuring and filling control method is carried out by processing and controlling the following: x...falling mass velocity (kg/sec)}. 6. After calculating the drop impact value by calculating the difference between the weight indication values W_n at each measurement point of the filling, and calculating the increase IW_n in the input weight per measurement interval using a calculation formula developed by expanding the regression formula,
The cumulative value CW_n of the weight increase is estimated, and the cumulative value CW is calculated.
6. The weighing and filling control method according to claim 5, wherein _n is repeated until it becomes equal to the set loading weight, and at the point when it becomes equal, the loading/unloading process is performed. 7. When putting more than the fixed amount of filling into the container into the measuring basket and sucking up the filling in excess of the fixed amount with the suction nozzle inserted into the measuring basket, weigh the filling in the measuring basket. In the process of stopping the operation of the suction nozzle and filling the container with the filling material in the weighing basket when the weight has decreased to a fixed amount, there is provided a means for detecting the rate of increase in the weight of the weighing basket in real time, and a means for detecting the weight of the powder in the basket in real time. A means for subtracting a predicted impact value from a weight indication value including the impact value, and a means for predicting the net input amount obtained by the calculation means and sending a supply shutoff signal to a shutoff valve when the predicted value reaches a set value. 7. The metering and filling control method according to claim 5 or 6, wherein the measuring and filling control method is performed using a dispensing means. 8. A weighing and filling control device that has a measuring mechanism for weighing the filling material, and is provided with a means for removing the filling amount exceeding the fixed amount from the measuring basket into which the filling amount exceeds the fixed amount to be filled into the container. , detecting means for detecting the rate of increase in the weight of the filling to be put into the weighing basket at regular intervals, converting it into a digital signal and outputting it; and an instruction means that calculates while predicting the filling amount and issues a supply cutoff signal when the predicted value reaches a predetermined filling set value, and in conjunction with the instruction means, the liquid is transferred to the lower part of the weighing basket via the removal means. A weighing and filling control device characterized by being equipped with a discharge mechanism for discharging a fixed amount of filling into a waiting container. 9. The weighing basket is equipped with a weighing device consisting of a load cell, and the measuring basket receives and stores the filling materials that are sequentially transferred, and opens the lower end opening at regular intervals for a predetermined time to measure the amount to be filled into the container. Claim 8: The supply hopper is provided below the lower end opening of the supply hopper, which is equipped with an opening/closing shutter for supplying the above quantity, and the opening/closing shutter is opened to store and measure the supplied filling quantity. The metering and filling control device described. 10. The filling removal means is a suction nozzle inserted into the filling stored in the measuring basket, and is linked to a measuring device that weighs the filling in the measuring basket,
This device is equipped with a control device that operates the suction nozzle when the feeding of the filling into the measuring basket is interrupted, and stops the operation of the suction nozzle when the filling reaches the set value due to the suction of the suction nozzle. A metering and filling control device according to claim 8 or 9. 11. The weighing and filling control device according to any one of claims 8 to 10, wherein the detection means is a converter that detects the rate of increase in the weight of the basket in real time while filling is being added. 12. A patent in which the calculation instruction means is a computer that estimates the weight of the filling in the weighing basket by subtracting the predicted impact value from the weight instruction value including the weight of the filling in the weighing basket and the falling impact value, and issues a command signal. Claims 8th to 11th
A metering and filling control device according to any one of the following paragraphs.