JPS62271817A - Weighing filling control method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

3. Detailed Description of the Invention [Field of Industrial Application] The present invention provides a high-speed, 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 an amount of FFL greater than the indicated weight, so this packaging trend is economical.
The loss of personnel is extremely large. Therefore, there is a demand for highly accurate weighing and speeding up of weighing operations to minimize variations in total weight during packaging. An example of a conventional method of this kind is to first supply less than the fixed amount of powder or granular material, such as detergent, into the space to be measured, and then to replenish the small amount by dispensing the insufficient amount. method was 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 changer, and the amount to be added is added to the weight to avoid underweight items. A method is adopted in which the filling weight is managed by setting it periodically. [Problem to be solved by the present invention] However, until the filling amount is corrected, the measurement (filling@) specification f
f1 (weight is the filling amount) is fixed, and there is generally a tendency to increase the filling amount to avoid underweight items, so the fluidity, bulk specific gravity, etc. of the material to be weighed (for example, powder or granules) to be carried in are Even if it is stable and only requires a small amount of filling, the amount of filling will be large to ensure safety, and the amount of filling will increase by that amount, which will worsen the filling yield. The micro-replenishment method not only requires a slowdown in the feeding speed for high-accuracy metering, but also takes a long time to weigh, making it impractical for filling processing operations. For this reason, attempts have been made to introduce a large amount in a short period of time and eliminate the surplus, but even if a large amount is added in a short period of time,
If there is a large input error, it will take time to balance the end point later,
High-speed filling is not possible. Moreover, the response speed of the electrical sensors used to measure weight in these cases is hundreds of times faster than that of mechanical frames, but in many cases, too much emphasis is placed on the stability of mounting, and excessive filters and dampers are installed. For this reason, it is currently used with a response speed comparable to that of mechanical frames, which limits high-speed filling. Moreover, when using electrical sensors or detection methods such as wire strain gauges, silicon diaphragms, and force balance methods in filling lines using gravimetric methods, individual scales, etc., external vibrations and various In order to suppress measurement errors and instability of indicated values due to electrical noise, etc., vibration damping materials are generally used to attenuate external vibrations, and filters are used to separate or suppress noise components. When the value changes over time), there is a time lag in the measured value and "distortion" of the signal waveform, which is a big problem especially in high-speed measurements.Also, even in static conditions, errors due to noise are unavoidable. Variation errors cannot be absorbed and there is a problem with accuracy. In order to eliminate these conventional drawbacks, the present invention employs predictive control that automatically corrects errors caused by temperature changes as well as noise and vibration during large-volume dispensing in order to perform high-accuracy, high-volume dispensing in a short time and reduce the burden on end-point balance. The object of the present invention is to provide a useful weighing and filling control method that enables high-speed, high-precision filling, and an apparatus that can effectively implement the control, 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 use a one-cycle speed amplifier that is unaffected by fluctuations in drop impact value (velocity, resistance with air). The object of the present invention is to provide a measuring and filling method that enables a significant improvement in measuring accuracy. [Means for Solving the Problems] The present invention is a weighing filling method in which after filling a container in an amount exceeding the fixed amount to be filled into a container is put into a weighing basket, the filling amount exceeding the fixed amount is removed and filled into the container. In control, when detecting the weight in the weighing basket, the values of the measurement sensor and comparison sensor installed on the same stand are compared, and the final output of the indicated value is performed when the predicted value reaches the target value. This measuring and filling control method and apparatus are characterized in that, after detecting the net input amount and cutting off the input of the filling material, the excess input amount is removed. [Embodiment] A preferred embodiment of the present invention will be described below based on the drawings. In FIG. When the net input amount is detected as the final output of the indicated value, the control device 5 This filling I is measured by the measuring device 3 and the suction nozzle 4 is activated, and then the suction nozzle 4 inserted into the measuring basket 2 sucks out the filling I' that exceeds the fixed amount. be done. Furthermore, the suction nozzle 4
The controller 5 controls the operation of the suction nozzle 4 when the amount of filling material ■ in the measuring basket 2 is weighed and reduced to a fixed amount.
The system is stopped at , the net weight of the filling is measured, and the container H is discharged and filled. 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 converter 6 to the supply hopper 1 is measured by the level gauge 7 and maintained at a constant level. An opening/closing shutter 8 is attached to the lower end opening of the supply hopper 1. This opening/closing shutter 8 is operated by a shutter drive solenoid 9.
When an open or close command is input from the control device 5, the opening/closing shutter 8 of the supply hopper 1 opens, and the falling filling material ■ is placed in the weighing basket 2 provided below the supply hopper 1. However, when the predicted filling value reaches the filling set value during filling, the shutter 8 opens and closes.
is closed to carry out loading/unloading, and the weighing is performed by a weighing device 3, for example, a load cell (L/C) provided in the weighing basket 2. In this weighing device 3, as shown in FIG. 3, in order to detect the net input amount, a measuring L/
A sensor 31 such as C and a sensor 32 such as a comparison L/C that can output a comparison signal are provided in close proximity to each other, and each sensor 31.3
The two outputs are compared by a comparator amplifier 33, filtered through a low-pass filter 34, and outputted as a final output α. Note that the pedestal 30 can also be provided on an installation base 36 with a vibration isolating material 35 as shown in FIG. Further, as the comparison amplifier 33, a differential amplifier is optimal. As shown in the example in Figure 5, the outputs of each sensor 31 and 32 are converted into gain amplifiers 37 and 38.
and low-pass filters 39 and 40, and may be compared by the comparison amplifier 41 to obtain the final output α, or the gain amplifier 38 and the low-pass filter 40 may be connected to the comparison sensor 32 side as shown in the example in FIG. It is also possible to provide an integral amplifier 381 with I4 between them so that the output of the sensor 32 is transmitted to the comparison amplifier 41. In these cases, in addition to accelerometers, various sensors such as magnetic sensors and semiconductor sensors can be used as comparison sensors. A suction nozzle 4 is inserted into the measuring basket 2, a discharge pipe IO is connected to the suction nozzle 4, a return device 11 is connected to the discharge pipe IO, and a suction device is connected to the return device II.

[2 is taken.] Further, a valve 13 is installed in the middle of the discharge pipe 10. This valve 13 is for opening and closing a hole 10a bored in the discharge pipe 10. When this hole 10a and a window 13a of the valve 13 match, air flows out through the hole. The suction knob 4 does not operate and the hole 10a
When the suction nozzle 4 is closed, the suction nozzle 4 is activated. This hole 10
The opening/closing of the valve 13 a is performed by the control device 5 by operating a valve drive solenoid 13'. The suction nozzle 4 has a double pipe structure, and outside air is introduced through the surrounding gap, and the introduced outside air and the filling material (1) are sucked into the discharge pipe 10 through the center gap and are discharged to the return device 11. Ru. This return device 11 includes a bag filter 14,
This bag filter 14 allows only air to be sucked into the suction device 12.
The excess amount of filling material ■' is stored in chamber I5 in return device II. The return filling ■' stored in this chamber 15 is fed back to the supply hopper 1 from the rotary valve 16.
is discharged to. A discharge gate 17 is attached to the lower end opening of the weighing basket 2, and a gate drive solenoid 1B 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 discharge gate 17 is opened and closed when the filling I in the measuring basket 2 reaches a fixed amount due to suction of the filling ■ by the suction nozzle 4, and the control device 5 reads the information from the measuring device 3 and controls the valve 13 to stop the suction operation, then operate the gate drive solenoid 18 to open the discharge gate 17, and the control device 5 reads the information from the metering device 3 to determine whether or not all the filling I has been discharged. Then, the control device 5 again turns on the gate drive solenoid 18.
Activate to close the discharge game (17). The filling I discharged from the inside of the weighing bath care Z passes through the filling chute 19 and is filled into the empty container ■. The control device 5 according to the present invention is configured to perform high-speed A in order to estimate the weight of powder in the basket 2 by detecting that the output of the comparison sensor in addition to the measurement sensor is the target value for weighing the basket 2. This is carried out using a combination of the /D converter 53 and the high-performance computer 54, and it is possible to obtain a density of 1/100 in a short time of, for example, 1.5 seconds, and then proceed to the subsequent suction and extraction process. In this case, the errors in this large amount of input are the drop impact, the amount of input after the closing of the loading shutter (shutter closing and space retention fit), the amount of air passing from the loading gate to the powder surface, and the amount of falling during the gate closing time. Therefore, in order to correct for these, the rate of increase in the weight is detected in real time, and the falling impact value at that point and the input amount after the closing of the input jack are also predicted, including the powder weight and impact value in the basket 2. It is preferable to estimate the powder weight in the basket 2 by subtracting the predicted impact value from the weight indication value, and the fluctuating falling impact value is also multiplied by a signal force n calculator 51 and multiplied several times by a multiplier 52. ] and expressed on the scale, 3
It is best to follow this at a speed of /1000 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 load is calculated using a proximal correlation equation with the parameters, and then the increase in weight of the weighing basket 2 of the actual device is detected at regular intervals.
The computer 54 programmed with the above-mentioned Yokan 2 analyzes the fall impact value and determines the true ff! It is better to set the amount increase to II. The weighing device 3 uses an electrical weight detection sensor with a fast response speed, such as a load cell or a force balance, and converts it into a digital signal via a signal adder 51 and an amplifier 52 that amplifies the output of the calculation sensor. A control mechanism includes a converter 53 of an A/D converter, and a computer 54 as an arithmetic command means. Measuring and filling device with mechanism (
The operation of the opening/closing shutter 8, valve 13, discharge gate 17, etc. shown in FIG. 2 is controlled. Initial constant setting means includes, for example, measurement time, measurement settling time, discharge time, quantity,
Number of sample data. It may be used with a setting section for standard values, tolerance rates, etc. The computer 54 that performs the calculation means performs a new calculation using the data from the constant setting means and the detected value from the detection means as input, and provides the result to the control means of the shutoff valve. 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 impact value of falling 1i 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 the temperature without being affected greatly by fluctuations. In addition, since the input amount after closing of the input shutter is determined by the factors of the closing of the input shutter and the amount of granular material retained in space, coefficients and constants depending on the type of granular material are taken into account. The high-speed A/D converter has a resolution of 12 bits,
It has a conversion speed of about 25 to 100 μs, and
As the computer, it is preferable to use a system in which a 16-bit microprocessor and an arithmetic processor are combined and driven by a 5 MHz clock. Furthermore, the weighing device 3 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 0.01
If a speed of about seconds is used, it is faster than the suction and discharge speed of 0.42 seconds, so it can be followed sufficiently. The weighing and filling method according to the present invention can be used to weigh and fill not only powdered materials but also liquids, slurries, sand, granules, and other raw materials that are dropped in a weighing machine capable of continuous weight measurement. be. [Effects of the Invention] In the present invention, since more than a fixed amount is supplied from the supply hopper to the weighing basket, the large-scale dispensing time at this time is slightly longer than that of the conventional method. This eliminates the dispensing process, which eliminates the inertia caused by falling during dispensing and the inability to control the filling while it is moving in the air, which prevents errors in measurement accuracy.Even when dispensing a large quantity in a short period of time, it is controlled to absorb variations in errors. High-speed filling is possible because there is little loading error, it does not take time to balance the end point, and the weight load can be reduced.Moreover, it is possible to measure the amount of filling in the basket by comparing the output of the measuring sensor with the output of the comparison sensor. When both outputs reach the target value, it is used as the final output, and external changes such as noise and vibration are offset to induce the target load, and errors due to temperature changes are also removed for measurement. It is possible to improve the time speed amplifier and weighing accuracy at the same time, and it is possible to quickly remove excess filling, so it is possible to combine the weighing device with an electrical weight detection sensor with a fast response speed.
It is possible to further improve the weighing accuracy, and because it is possible to control the loading error in large quantities to the smallest possible range, it is expected that the filling yield will be significantly improved, and the entire filling cycle will be faster and more accurate. This makes it possible to significantly reduce errors caused by stacking and location.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the control tIII principle of the present invention, Fig. 2 is a schematic diagram of the main part configuration of the weighing control device, Fig. 3 is a flow sheet of the weighing device, and Fig. 4 is an illustration of another embodiment of the weighing device. The flow sheet, FIGS. 5 and 6 are circuit diagrams of the other side. 1... Supply hopper, 2... Measuring basket, 3...
...Measuring device, 4...Suction nozzle, 5...Control device, 8...Opening/closing shutter, 17...Discharge gate, 30
... Frame, 31... Sensor for measurement, 32... Sensor for comparison, 33... Comparison amplifier, 34... Filter, 35... Vibration isolating material, 36... Installation stand, 37 .3
8... Amplifier, 38°... Integrating amplifier, 39.40
... Filter, 41 ... Comparison amplifier, 51 ... Signal adder, 52 ... Multiplier, 53 ... Convergence,
54...Computer, ■...Filling material, ■...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. When detecting the weight in the basket, the value of the measurement sensor and comparison sensor installed on the same stand are compared, and when the predicted value reaches the target value, the net input amount is calculated as the final output of the indicated value. After detecting and blocking the filling,
A measuring and filling control method, characterized in that the excess input amount is eliminated. 2. The first aspect of the present invention is characterized in that the net input amount is predicted when the outputs of both the measurement sensor and the comparison sensor become the same.
The metering and filling control method described in section. 3. In order to predict the net input amount, the output due to noise and vibration exerted on the sensor installation frame is expressed in the same way on the measurement sensor and the comparison sensor, and this is canceled out to induce the target load to cut off the filling input. The measuring and filling control method according to claim 1 or 2, wherein the measuring and filling control method is performed by issuing a signal. 4. 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 weighing basket into which the filling amount exceeds the fixed amount to be filled into the container. A sensor for weighing and measuring the filling to be put into the weighing basket and a comparison sensor are arranged in close proximity on the same stand, and a comparison amplifier and filter are provided to compare the outputs of both sensors, and and an indicating means for deriving the final output that has reached the target load from the filter and issuing a loading/cutting signal, and in conjunction with the indicating means, the final output is quantitatively weighed into a container waiting below the weighing basket via the removing means. A measuring and filling control device characterized by being equipped with a discharge mechanism for discharging the filled material. 5. 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 4: The supply hopper is provided below the lower end opening of a supply hopper equipped with an opening/closing shutter for supplying the above quantity, and stores and calculates the amount of filling which is supplied when the opening/closing shutter opens. The metering and filling control device described. 6. 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, and Claim 4: The device is equipped with a control device that operates the suction nozzle when the supply is interrupted, and stops the operation of the suction nozzle when the filling material reaches a set value due to the suction of the suction nozzle. The metering and filling control device according to item 1 or 5. 7. A computer that calculates the falling impact value of the weighing basket every moment that occurs during the charging of the filling and predicts the net input amount, and a mount that is installed directly on the installation stand or via a vibration isolating material. The measuring and filling control device according to any one of claims 4 to 6, further comprising the measurement sensor and the comparison sensor.