JPH0612289B2 - Quantitative filling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a constant quantity filling device for filling a container with a fixed volume of articles such as powder and granules.

<Prior Art> The quantitative filling device described above is widely used because it has an advantage of a high filling speed. However, when the density of the articles contained in the device changes, it is filled in a container. The articles may have different filling weights even if they maintain a predetermined volume. Generally, since the commerce of packing is often performed on the basis of weight rather than volume, it is desirable that the packing weight is constant.

Therefore, conventionally, after filling a container with a quantitative filling device, a weighing conveyor is provided in the middle of the line for transporting the container, and by weighing the filling material, information indicating the tendency of the filling weight can be obtained. The amount of filling from the quantitative filling device has been controlled based on this information.

In addition, a scale is placed near the fixed quantity filling device, an appropriate number of filled containers are extracted by a worker from the transfer line, the filling material of each container is weighed, and the fixed quantity filling device is measured based on each measured value. Some also manually adjust the filling amount.

<Problems to be Solved by the Invention> However, with the above-described metering conveyor, there is a problem that the metering conveyor is expensive and takes a large space. In addition, when a worker uses a scale to measure, the above-mentioned problems do not occur, but there is a problem that it is troublesome to measure each time.

It is an object of the present invention to provide a constant quantity supply device which solves the above two problems at the same time.

<Means for Solving Problems> The present invention, like the conventional constant-volume supply device, provides an article supply device whose unit product supply amount is substantially constant, and a signal proportional to the supply amount from the product supply device. When the means for generating, the storage means for storing the set value proportional to the predetermined supply amount, and the output of the proportional signal generating means and the storage value of the storage means match, the article supply device is stopped. Comparing means for supplying a signal.

The present invention further has weighing means for weighing the articles supplied from the article supply device in a stationary state. There is provided means for obtaining the weight of a fixed amount of a plurality of articles supplied from the article supply device by means of a weighing means and calculating an average value thereof. The calculation means calculates the deviation between the weight corresponding to the predetermined supply amount and the average value. The calculation means performs a calculation for dividing the product of the deviation and the set value by the average value. The calculated value is subtracted from the set value, and the subtracting means stores it in the storage means.

<Operation> According to the present invention, it is possible to sequentially supply an article having a constant volume by the article supply device, the proportional signal generation means, the storage means, and the comparison means. In this way, a plurality of the articles having a constant volume supplied are extracted and weighed by the weighing means. The average value of the weights of the plurality of articles is calculated by the average value calculating means. This average value is considered to be the true weight of multiple items. The weight corresponding to the predetermined supply amount, that is, the deviation between the target weight and the average value represents the deviation between the true weight and the target weight. The calculated value represents the deviation with respect to the set value corresponding to the deviation of the weight. By subtracting this deviation from the set value,
Articles can be supplied in constant weight increments.

<Example> This example has a hopper 2 as shown in FIG.
A screw feeder 4 is provided in the hopper 2, and the screw feeder 4 is rotated by a motor 6. 8 and 10 are pulleys, 12 is a belt, and 14 is an electromagnetic clutch. By rotating the screw feeder 4 once, the volume of the article (for example, powder) supplied to the container 16 is substantially constant. 1 for the screen feeder
A disc 18 is provided with holes formed only at a number of places. Optical detectors 20a and 20b are provided so as to face each other across the disc 18. The number of pulses generated by the optical detectors 20a and 20b can detect the number of revolutions of the screw feeder 4, that is, the volume of the article supplied to the container 16.

The pulses from the optical detectors 20a and 20b are supplied to a counter 24 via an AND gate 22 as shown in FIG.
Further, the set pulse storage unit 26 shown in FIG.
A certain number of pulses N is set via a ten-key pad (not shown) via 28. This pulse number N is based on the article supply volume per rotation of the screw feeder 4 and the density of the article (provided that this density is maintained at a constant value), but the test weight of the article 16 is stored in the container 16. Is the number of rotations of the screw feeder 4 required to supply the screw feeder.

This rotation speed is theoretically determined, and in reality, due to various factors, it is not always possible to supply the test weight of the article to the container 16 by the pulse speed. Therefore, for the time being, the above pulse number is set, a test operation is performed, and the pulse number is corrected based on the result.

First, the correction method will be described. It is now assumed that the motor 6 is rotating and the electromagnetic clutch 14 is turned off.
If the pushbutton switch 30 is closed in this state, F ・ F
(Flip / Float) 32 Q output becomes H level,
Energize the driver 34 of the electromagnetic clutch 14. As a result, the electromagnetic clutch 14 is connected, the screw feeder 4 rotates, and the supply of articles to the container 16 is started. On the other hand, F ・ F
OMV (one-shot multivibrator) 36 generates a pulse when the output of 32 becomes H level, and F ・
The Q output of F38 becomes H level, the AND gate 22 is opened, and the pulses of the optical detectors 20a and 20b are counted by the counter 24.

When the count value of the counter 24 and the stored value N of the set pulse storage unit 26 match, the output of the comparator 40 becomes H level, OMV42 generates a pulse, FF32 is reset, and the driver 34 is deenergized. Then, the electromagnetic clutch 14 is turned off. However, the screw feeder 4 continues to rotate due to a delay in the operation of the driver 34 and the electromagnetic clutch 14. When this rotation is stopped, the output of the timer 44 energized by the H level output of the comparator 40 becomes H level, the OMV 46 generates a pulse, and the F / F 38 are reset. By this,
The count value of the counter 24 is accumulated by the accumulator 48, and the counter 24 is reset. The OMV 46 pulses are counted by the counter 50.

On the other hand, the container 16 that has been filled is loaded and weighed on the balance 54 shown in FIG. This measurement signal is digitalized by the A / D converter 56. Thereafter, this is repeated n times, and n containers 16 are loaded on the scale 54.

As a result of being repeated n times, the weighing signal of the scale 54 (the weight of the articles in the n containers) is W _T , and the accumulated value of the accumulator 48 (the optical detectors 20a and 20b are generated during the supply of n times). The total number of pulses) has reached M _T. If you operate conversion key 58 in this state, M _T
The value Ko (the number of pulses per 1 g) divided by W _T in the divider 60 is stored in the storage unit 62. At the same time, M _{T is set} to n (n is a counter
(Given by 50) is divided by a divider 64 to calculate the number of pulses per supply, and the subtractor 66 calculates the calculated value M _T
Deviation from N by subtracting the setting pulse N from / n (rotational speed at which the screw feeder 4 rotates even when a stop signal is received due to the time delay of the driver 34 and the electromagnetic clutch 14)
Is calculated and stored in the storage unit 68. Note that n may be set without counting.

Next, when the actual filling work is performed, the setting unit 70 sets the target weight Wo (which may be larger or smaller than the test weight) in the storage unit 72, and the multiplier 74 calculates Ko and Wo. The product of the target weight and the
Is subtracted by a subtractor 76 from the number of revolutions of the screw feeder 4 to be charged into the set pulse storage unit 26, supplied to the setting pulse storage unit 26 via the OR gate 28, and stored therein.

In FIG. 2, dividers 60, 64, subtractors 66, 76, multipliers 74
, Even when the conversion key 58 or the setting section 70 is not operated,
Although they are shown as performing arithmetic operations,
The calculation operation may be performed only when the conversion key 58 or the set value 70 is operated.

After that, the filling work is performed. However, even if the target weight is set as described above, if the density of the articles changes, the container 16 can be charged by the target weight.
Can no longer supply goods. This change in density does not occur suddenly but gradually due to humidity, storage conditions and the like. Therefore, the operator sometimes extracts the filled container from the transfer line and loads it on the scale 54. As a result, an appropriate number of containers 16 are loaded on the scale 54, and the weighing signal of the scale 54 is assumed to be W _T ′.

In this state, when the filling correction key (not shown) is operated, W _T ′ is divided by Wo by the divider 78, and the divided value is converted into an integer by the integer conversion circuit 80, whereby the container on the scale 54 is The number r is calculated. Note that r may be set without being calculated. Then, W _T ′ is divided by r by the divider 82 to obtain the average weight Wm. The deviation ΔW is obtained by subtracting the target weight Wo from the average weight Wm by the subtracter 84. At the same time, the storage value Pc of the set pulse storage unit 26 and the storage value of the storage unit 68 are added by the adder 86 to calculate the total number of pulses. This total number of pulses is divided by the average weight Wm by the divider 88 to obtain the number of pulses K ₁ per 1 g, and this is stored in the storage unit 62,
ΔW is multiplied by the multiplier 90 to obtain the number of pulses ΔP corresponding to the deviation weight. This ΔP is subtracted from Pc by the subtractor 92,
It is stored in the set pulse storage unit 26. Then, thereafter, the filling operation is performed in the same manner as described above.

In the above description, the dividers 78, 82, 88, the subtracters 84, 92, the adder 86, and the multiplier 90 are operated by operating the filling correction key. The setting pulse storage unit 26 and the storage unit 62 may be stored only when the arithmetic unit performs the arithmetic operation and operates the filling correction key.

Further, in the above description, it is assumed that the deviation with respect to Pc is constant, but if it is highly likely that the deviation is not constant,
Each time the filling is separately performed, the number of rotations is calculated, the average value thereof is calculated, divided by Wm to obtain K ′, which is stored in the storage unit 62, and Pc is subtracted from the above average value. The deviation 'is obtained and stored in the storage unit 68, and thereafter,' is subtracted from the product value of Wo and K'to obtain Pc, and ΔW is multiplied by K'to obtain ΔP. ΔP may be subtracted from Pc and stored in the setting pulse storage unit 26.

In the above embodiment, the articles were placed on the scale 54 in order, and the accumulated value was obtained by leaving it, but an accumulator was provided,
If the accumulated value is obtained by this, it is not necessary to leave the article on the scale 54. Further, if the counter counts the number of articles placed on the scale 54 and the above-mentioned correction calculation is automatically performed when the count value reaches a predetermined value, the operation of operating the filling correction key is omitted. can do.

Further, in the above description, the screw feeder 4 in which the supply amount per one rotation is constant is used, but it is also possible to use the screw feeder 4 in which the supply amount per unit time is constant. In that case,
In the above embodiment, the number of pulses may be all times.

<Effect> As described above, according to the present invention, articles can be supplied in constant weight units by a simple operation of placing the articles on the static weighing means. Moreover, the static weighing means is less expensive than the weighing conveyor and requires a smaller installation space.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of one embodiment of a metering and filling device according to the present invention, FIG. 2 is a block diagram of another part of the same embodiment, and FIG. 3 is a diagram showing a mechanical structure of the same embodiment. Is. 2, 4 ... Article supply device, 24 ... Proportional signal generating means, 26
...... Memory means, 40 …… Comparison means, 54 …… Weighing means, 78,
80, 82 ... average value calculating means, 84 ... deviation calculating means, 88,
90: calculation means, 92: subtraction means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 56-148019 (JP, A) JP 57-57134 (JP, A) JP 58-167922 (JP, A) JP 60- 18721 (JP, A) Actually opened 60-13302 (JP, U)

Claims (1)

[Claims] 1. An article supply device in which a unit article supply amount is substantially constant, means for generating a signal proportional to the supply amount of the article supply device, and a set value proportional to a predetermined supply amount are stored. Storage means, comparing means for supplying a stop signal to the article supply device when the output of the proportional signal generating means and the stored value of the storage means match, and the article supplied from the article supply device in a stationary state. Weighing means to measure with,
Means for calculating the average value of the weights of the articles weighed a plurality of times by the weighing means, means for calculating the deviation between the weight corresponding to the set value and the average value, the deviation and the above A quantitative filling device, comprising: a calculation unit that divides a product of a set value and the average value to obtain a divided value; and a subtraction unit that subtracts the divided value from the set value and stores the subtracted value in the storage unit.