JP2780983B2 - Filling amount control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filling amount control device, and more particularly to a filling amount control device, which is used in a manufacturing process of pharmaceuticals and the like, and stores 50 mg in an empty container such as a vial or an ampoule that is sequentially conveyed. 100mg, 5
In a filling device for filling a small amount of powder, liquid, or the like having a fixed amount of several g or less such as 00 mg and 1000 mg, the filling amount is weighed, and the weighed value is fed back to control the filling machine, and thus the filling amount is quantitatively controlled. Is what you do.

2. Description of the Related Art Conventionally, in the filling process of this kind of pharmaceuticals, the filling amount is generally checked by extracting a container filled with powder, liquid, or the like from a line at an appropriate time, weighing the container, and calculating a calculated filling amount and a target amount. If there is a difference, the apparatus for filling the contents into the container is subjected to an appropriate treatment to adjust the filling amount.

Generally, in a powder filling apparatus, the filling amount fluctuates due to a temporal change in a bulk hopper level (prepared amount), specific volume, physical properties, and the like. Since the filling amount fluctuates due to changes, clogging of the needle tip filter, loosening of the cylinder, etc., the above-mentioned filling amount is checked at an appropriate frequency and the filling amount is adjusted.

However, in the filling step, in addition to the above-described temporal fluctuation, an abnormal fluctuation in the filling amount may occur due to a sudden problem due to some trouble. At this time, the above-described conventional appropriate sampling check cannot check for an abnormality in the filling amount due to a sudden reason. In particular, in pharmaceutical products, the filling amount is required to maintain extremely high precision, and it is required that absolutely no defective products are produced. there were.

To deal with the problem that occurs when the above-mentioned sample is weighed, Japanese Patent Publication No. 62-25971 describes that a rough filling machine first
%, A coarse filling amount is measured, the coarse filling amount is measured, and a correction filling machine is feed-forward controlled based on the measured value to perform correction filling, and a filling amount control device has been proposed. However, the control device is intended for a large filling amount, and the filling amount targeted by the present invention is 50 mg, 100 mg, 500 m
It is difficult to apply to small quantities of several g or less such as g, 1000 mg, and requires two filling machines and three balances for all weighing, which makes the equipment complicated. In addition, there were problems such as an increase in cost. Also,
In 78583, a weighing device is provided below the filling machine, and a device for filling while weighing is provided.However, this device has poor accuracy and a low speed, and as described above, for small amounts, It is difficult to adopt.

Problems to be Solved by the Invention As described above, the conventionally provided apparatus for controlling the filling amount while weighing is difficult to employ in the case of a small filling amount targeted by the present invention, and it is difficult to employ the filling speed. Since the weighing speed is slower than that of, when all the weighing is performed, the productivity is remarkably reduced and the control system is not sufficient.

In addition, when the filling machine is driven and a predetermined number of containers are sequentially and successively filled after charging a fixed volume of the material to be filled into the hopper of the filling machine, the filling amount in the initial mode at the start of the filling machine is reduced. In addition to individual variations, there is a large tendency to fluctuate,
In addition, even in the final mode in which the amount of material to be filled is small, individual variations have a large tendency to vary. In the steady mode between the initial mode and the final mode, the variation is the smallest, but there is a temporal variation such that the mode gradually increases and decreases. As described above, there is a characteristic in the variation and fluctuation tendency of the filling amount according to the operation timing of the filling machine.Therefore, even when uniform feedback control is performed from the time of starting to the time of stopping, for example, all the parts are weighed and several pieces are weighed. When the feedback control is performed with the average value of the filling amount data, the controllability is good when the filling amount is stable, but in the initial mode and the final mode where the fluctuation tendency is large, the feedback cannot sufficiently follow the fluctuation tendency. If feedback control is performed one by one in order to follow the change of the filling amount in the initial and final modes, one sudden variation in the stable period of the steady mode will be picked up. There is a possibility.
Even if it is possible to weigh all 100 pieces, it is also a problem how to perform feedback control based on the weighing result.

The present invention has been made in view of the above-described problem, and in a filling device capable of weighing all items without reducing productivity, by performing feedback control according to the operation timing of the filling machine, the filling is performed. Hold down the variation of the amount,
The purpose is to maintain the filling amount in the container within a certain control range.

Means for Solving the Problems In order to achieve the above object, the present invention provides a first electronic balance for weighing empty containers, and a container for storing a predetermined amount of powder from a container after weighing the empty containers. A filling machine for filling the powder with the powder, a second electronic balance for weighing the filling container for weighing the container filled with the powder, a weighing value of the empty container by the first electronic balance, and a filling by the second electronic balance. The net filling amount of the filled powder is calculated from the weighed value of the container and the net filling amount, the target filling amount and the drive control of the motor of the filling machine from the motor driving data of the filling machine at the time of the filling are feedback-controlled, and The feedback control includes an initial mode and a final mode corresponding to the initial and final stages of the filling in which the filling amount varies widely, and a steady state corresponding to a stationary period in which the filling amount varies little between these initial and final periods. In the initial mode and the final mode, feedback control is performed based on the latest data, and in the steady mode, feedback control is performed based on continuous average data including a plurality of times including the latest data. And a filling amount control device characterized by comprising:

Effect According to the filling amount control device of the present invention, since a weighing device capable of weighing all items without impairing the productivity of the filling step is used, feedback control according to the previous weighing data is also possible. In addition, since the feedback control method is changed for each operation mode that has characteristics peculiar to the variation of the filling amount and the tendency to change, feedback control suitable for each operation mode can be performed. It can be kept to a minimum.

Examples Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

FIG. 1 shows the entirety of a powder filling device provided with a filling amount control device according to the present invention, wherein 1 is a container composed of a vial, 2
Is a supply conveyor for empty containers, and 3 is a first for weighing empty containers.
An electronic balance, 4 is an auger powder filling machine for filling the empty container after weighing with the first electronic balance 3, 5 is a second electronic balance for weighing the container after filling the powder, and 6 is a weighing value predetermined management. Defective product elimination device for rejecting defective products outside the width, 7
Denotes a take-out conveyor, and 9 denotes a container transfer device. The container transfer device 9 is provided with four chucks 8A, 8B, 8C, 8D (the chucks 8D are not visible in the drawing) at regular intervals as shown in FIG. The operation bar 11 is attached to a drive mechanism 12 installed on a base 10.

The drive mechanism 12 simultaneously moves the four chucks 8A, 8B, 8C and 8D attached to the operation bar 11 in the same locus in X, Y and Z directions.
The container 1 sucked and held by the chuck 8A is moved from the supply conveyor 2 to the first electronic balance 3, and the emptied container 1 is moved from the first electronic balance 3 to the powder filling machine 4 by the chuck 8B. The container 1 after powder filling by 8C is transferred from the powder filling machine 4 to the second electronic balance 5 by the chuck 8D, and transported from the second electronic balance 5 to the defective product discharging device 6 by the chuck 8D by one container transfer device 9 simultaneously. Is going.

The powder filling machine 4 used in the present apparatus uses an auger screw filling machine as shown in FIG.
A predetermined amount of powder 22 charged into the container 1 is filled into the container 1 through a screen 25 and a skirt 26 in accordance with the amount of rotation by an auger screw 24 rotated by a driving device 23. As the driving device 23 of the auger screw 24, a pulse setting type servomotor is used. For example, the auger screw 24 is rotated four times by 20,000 pulses for one container, and the container 1 is filled with 100 mg of powder. Is set as follows.

As described above, in this device, for all containers,
The empty container is weighed by the first electronic balance 3, and the container after powder filling is weighed by the second electronic balance 5, and each weighed value is input to a data processing device (not shown). By subtracting, the amount (net weight) of the powder filled in all the containers is calculated, that is, the total number is weighed.

In the data processor for calculating the total weighing value, a servo motor for driving the auger screw 24 is calculated from the calculated net weight, the target weight, and the rotational movement pulse (pulse of the servo motor) of the auger screw 24 at the time of filling. Feedback control, so that powder into container 1
The filling amount (net weight) of 22 is controlled so that it can be maintained within a certain management range. In addition, there is a specific variation in the filling amount depending on the operation mode from the start to the stop of the filling machine 4, and therefore, the configuration of the feedback control is changed according to the operation mode.

That is, generally, at the time of powder filling by the powder filling machine 4,
After charging a predetermined large amount of powder 22 into the funnel 21, the funnel 21 is covered with a cover (not shown) to seal the powder,
In this state, as described above, by starting the servomotor and rotating the auger screw 24 intermittently, a predetermined amount of powder is sequentially fed to the container 1 being conveyed.
When the powder 22 charged in the funnel 21 runs out, the drive of the servomotor is stopped and a predetermined amount of powder is charged into the funnel 21 again. For example, with one powder input to funnel 21,
1000 containers are filled with 100 mg of powder each.

In the auger filling machine 4, the variation in the filling amount is large in the initial mode for a certain period from the start of the servomotor, but the variation is small in the subsequent steady mode,
The dispersion increases again in the final mode.

The following feedback control system is configured according to the operation mode of the filling machine 4 described above.

Initial mode: Feedback control by n = 1 Vn = Vn-1.Xs / Xn-1 Steady mode: Feedback control by n = 5 Vn = Vn-1.Xs / Xav Final mode: Feedback control by n = 1 Vn = Vn −1 · Xs / Xn−1 In the above equation, V: the rotational movement amount of the servo motor, n: this time, n−1: the previous time, Xs: the target filling amount, Xav: the average filling amount for five times, Vn: The amount of pulse rotation movement of the current servo motor under feedback control Vn-1: The amount of pulse rotation movement of the previous servo motor The switching from the initial mode to the steady mode and the steady mode to the final mode was specified in advance. According to the mode switching reference, the switching is performed when a plurality of continuous lines reach the reference.

The reason why the feedback control is that the initial mode and the final mode are n = 1 as described above is that the servo motor is feedback controlled each time in accordance with the previous powder filling amount because the filling amount varies greatly in these modes. This is because the powder filling amount for each container can be within the target management range in the initial and final modes.

On the other hand, in the steady mode, the variation of the filling amount is small,
If control is performed for each previous powder filling amount, on the contrary, if the filling amount fluctuates due to a sudden factor, feedback control will be performed based on the data, so that the filling amount after control falls within the target management width. There is a problem that disappears. Therefore,
In the steady mode, n = 5, and feedback control is performed based on the average value of the five filling operations.

In the filling device shown in FIG. 1, the container to be filled by the auger filling machine 4 is used to calculate the net weight by the data processing device after weighing by the second electronic balance 5 because of the relationship between the container before and after the previous one. , All of (n-1) in the above formula become (n-2).

The control method of the present invention in which feedback control is performed separately in the above-described initial mode, steady mode, and final mode, the case where the servo motor is driven with a constant pulse without performing feedback control, and the operation mode is not divided into the operation mode from start to stop. Experiments were conducted on the case where feedback control was performed with n = 1 and n = 5 throughout.

In this experiment, the number of fillings was 700, the target filling amount was 100 mg,
The failure standard was set at ± 7%.

The experimental results are as shown in Table 1 on the next page, and the results of the present invention are shown in FIG. 3 and in the case of no control, the results are shown in the graph of FIG.

Effects As is apparent from the above description, according to the filling amount control device according to the present invention, a weighing machine including an electronic balance is incorporated before and after the filling machine in the filling line, and the total number of the weighing machines is not hindered in the filling process. Since weighing can be performed, feedback control of the auger screw driving servomotor based on the total weighing can be performed. In addition, as a tendency of the auger filling machine, the variation in the filling amount is an initial,
The stationary phase and the final phase are characterized, but in the present invention, the initial phase,
Since the steady-state period, the final period, and the operation mode are defined and the feedback control method is changed, feedback control suitable for each mode can be performed. In this way, the filling accuracy can be improved throughout, and the occurrence of defective products whose filling amount is out of the control range can be suppressed as much as possible.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a powder filling device using a filling amount control device according to the present invention, FIG. 2 is a sectional view of a main part of the powder filling machine, and FIG. FIG. 4 is a diagram when the filling amount is not controlled. DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Supply conveyor, 3 ... 1st electronic balance, 4 ... Powder filling machine, 5 ... 2nd electronic balance, 6 ... Defective product removal apparatus, 21 ... Funnel, 22 ... Powder, 24 ……
Auger screw.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65B 1/00-3/36

Claims (2)

(57) [Claims] 1. A first electronic balance for weighing empty containers, a filling machine for filling the containers after the empty containers are weighed from a storage section containing a predetermined amount of powder, and a filling machine for filling the powders A second electronic balance for weighing the filled container for measuring the weight of the container; and a net filling amount of the filled powder from the weighed value of the empty container by the first electronic balance and the weighed value of the filled container by the second electronic balance. Calculating and performing feedback control of the driving of the motor of the filling machine from the net filling amount, the target filling amount, and the motor driving data of the filling machine at the time of the filling, and the feedback control is performed in the initial stage of the filling in which the variation in the filling amount is large. And a final mode corresponding to the final period, and a steady mode corresponding to a stationary period in which the amount of filling varies little between the initial and final periods. And a data processing device that performs feedback control based on average data of a plurality of continuous times including the latest data in the steady mode in the steady mode. To control the filling amount. 2. An auger filling machine using an auger screw rotated by a pulse setting type servomotor as said filling machine, and said auger filling machine is used as motor drive data of said filling machine at the time of said feedback control. Using the data of the rotational movement pulse of the motor, the rotational movement pulse of the servomotor is controlled by feedback control, and the auger filling machine is transferred from the first electronic balance to the first electronic balance from the empty container conveying means. 2. The filling amount control according to claim 1, further comprising a transfer device for holding and automatically transferring the container from the auger filling machine to the second electronic balance and from the second electronic balance to the defective product removing device. apparatus.