JPH02258501A - Filling quantity control device - Google Patents

Abstract

PURPOSE:To prevent the dispersion of filling quantity and make it possible to keep the filling quantity into a container to be within a fixed control range by a method wherein a feedback control which corresponds to the operational periods, initial period, normal period and final period, of a filling machine is performed in a filling device for which total scaling is available. CONSTITUTION:For all containers, a scaling of the empty container is performed by a first electronic balance 3, and also, a scaling of the container is performed by a second electronic balance 5 after a powdery object has been filled in the container. Then, the filled quantity of the powdery object for every container is calculated by subtracting at a processing unit, i.e., a total scaling is performed. Since the dispersion of filling quantity is larger in the initial mode and final mode, depending on the previous filled quantity of the powdery object, giving feedback control to the servomotor every time is preferable to make it possible to keep the filling quantity in the objective control range. In the meantime, in the normal mode, the dispersion of the filling quantity is smaller, and in case the filling quantity varies due to a sudden cause, there is a possibility that the filling quantity after the control may not stay in the objective control range. Therefore, the feedback control is performed by an average value of five previous fillings.

Description

[Detailed Description of the Invention] The present invention relates to a filling amount control device, and more specifically, to empty containers such as vials or ampoules that are used in the manufacturing process of pharmaceutical products and are sequentially transported. 50mg, 100
In a filling device that fills a small amount of powder, liquid, etc. in a fixed amount of several grams or less, such as mg, 500 mg, IOOmg, etc., the filling amount is weighed, and the weighed value is fed back to control the filling machine, so that the filling m This is to quantitatively control.

Conventional technology In the past, in the filling process for this type of pharmaceutical products, the filling amount was generally checked by removing containers filled with powder, liquid, etc. from the line at a timely manner, weighing them, and checking the calculated filling m.
If there is a difference between the container and the target amount, appropriate measures are taken on the device that fills the container with the contents to adjust the filling amount.

In general, in powder filling equipment, the filling amount fluctuates due to changes over time in the bulk hopper level (feeding amount), specific volume, physical properties, etc. Also, when filling liquids (including suspending agents), etc., the viscosity changes. Since the filling amount fluctuates due to changes, clogging of the needle tip filter, loosening of the cylinder, etc., the filling amount is checked at a moderate frequency and the filling ml is adjusted.

However, in the filling process, in addition to the above-described fluctuations over time, abnormal fluctuations in the filling amount may occur due to unexpected reasons due to some kind of trouble. In this case, it is not possible to check for abnormalities in the filling amount due to sudden reasons using the above-mentioned conventional appropriate sampling check. In particular, for pharmaceuticals, it is necessary to maintain extremely high accuracy in the filling amount, and it is also required to absolutely avoid producing defective products, so there are problems that cannot be adequately addressed with conventional sample weighing. there were.

To deal with the above-mentioned problems that occur when sampling and weighing, in Japanese Patent Publication No. 62-25971, first, a rough filling machine is used to
A filling amount control device has been proposed that performs rough filling of 0 to 90%, then measures the rough filling amount, and performs feedforward control of a correction filling machine based on the measured value to perform correction filling.

However, this control device is intended for products with a large filling amount, and the filling amount targeted by the present invention is 50 mg,
It is difficult to apply to small quantities of several grams or less, such as 100mg, 500mg, and 1000mg, and it requires two filling machines.
In addition, three balances were required to weigh the entire quantity, which led to problems such as complicated equipment and high costs. In addition, in Japanese Patent Publication No. 52-78583, a device is proposed in which a weighing device is installed below the filling machine and filling is performed while weighing, but this device has poor accuracy and slow speed, and Similar to the above, it is difficult to use for small quantities.

Problems to be Solved by the Invention As mentioned above, the conventionally provided devices that control the filling amount while weighing cannot be used for filling small amounts of m
In this case, it is difficult to adopt the method, and since the weighing speed is slow compared to the filling speed, if all units are weighed, the productivity will drop significantly and there is a problem that the control accuracy is not sufficient.

In addition, when the filling machine is driven to sequentially and continuously fill a predetermined number of containers after putting a certain volume of material into the hopper of the filling machine, the initial mode at the start of the filling machine is the filling m In addition to individual variations, there is a large tendency to fluctuate, and even in the final mode when the amount of material to be filled is small, there is a large tendency for side-to-side variations to fluctuate. The steady mode between the initial mode and the final mode has the least variation, but there are variations over time that gradually increase and decrease.

As described above, there are characteristics in the dispersion and fluctuation tendency of the filling amount depending on the operation timing of the filling machine, so even if -temporal feedback control is performed from start to stop, for example
When performing feedback control using the average value of several filling amount data after weighing all items, the controllability is good when the filling amount is stable, but in the initial mode and final mode where there is a large tendency to fluctuate, the feedback is not sufficient to control the fluctuation tendency. However, if feedback control is performed one by one to follow the fluctuations in the filling amount in the initial and final modes, it is difficult to follow the fluctuations in the filling amount in the initial and final modes. There is also the possibility of overcoming variations. Even if complete weighing became possible in this way, there was a problem in how to carry out feedback control based on the weighing results.

The present invention was made in view of the above-mentioned problems, and is a filling device that enables full scale weighing without reducing productivity, by performing feedback control according to the operation timing of the filling machine. This suppresses variations in the amount of filling and allows the amount of filling into the container to be maintained within a certain control range.

Means for Solving the Problems In order to achieve the above-mentioned objects, the present invention provides a first electronic balance for weighing empty containers, and a pulse setting type surfo motor that rotates the containers after weighing the empty containers. A filling machine such as an auger filling machine that fills powder, etc. using an auger crew, and No. 271 for weighing a filling container that weighs after filling. The 11th item above from the child balance and the means for transporting empty containers! To the child balance, the 11th
a conveying device that holds and automatically transports containers from the child balance to the auger filling machine, from the auger filling machine to the second electronic balance, and from the second N child balance to the defective product removal device; The net filling amount is calculated from the weighed value and the weighed value of the filling container by the 21st child balance, and the morph of the filling machine when the net filling m, the target filling amount and the above-mentioned weighed object is filled is calculated. The driving of the filling machine motor is feedback-controlled by controlling the rotational movement pulse of the motor based on the drive data (for example, the rotational movement pulse of the motor, etc.), and the feedback control is performed to control the fluctuation tendency of the filling m. In the initial mode and final mode of a filling machine with a large filling amount, feedback control is performed for each previous filling result, and in a steady mode where the filling amount has a small tendency to fluctuate, feedback control is performed based on the average value of multiple consecutive times, such as 5 times including the previous time. The present invention provides a filling amount control device characterized by comprising a data processing device as described above.

Function: According to the filling amount control device of the present invention, since a weighing device that can perform complete weighing without impairing the productivity of the filling process is used, feedback control according to the previous weighing data is also possible. Moreover, since the feedback control method is divided into operating modes that have characteristics specific to variations and fluctuation trends in the filling amount, feedback control suitable for each operating mode can be performed, and in each mode, it is possible to
Filling defects can be kept to a minimum.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

FIG. 1 shows the entire powder filling apparatus equipped with a filling m control device according to the present invention, where 2 is a container made of vials, 2 is a conveyor for supplying empty containers, and 3 is a first container for weighing empty containers.
lf balance, 4 is an auger powder filling machine that fills the powder into the empty container after weighing with the first electronic balance 3, 5 is the second electronic balance that weighs the container after filling the powder, and 6 is the weighing value. A defective product elimination device that eliminates defective products that fall outside of a predetermined control range;
7 is a take-out conveyor, and 9 is a container conveyance device. The container transport device 9 has four chucks 8A, 8I3, 8G, and 8D (however, the chuck 8D is not visible in the figure) at regular intervals as shown in the figure in order to transport the container 1 to each of the above devices. It is attached to a long operating bar 11, and the operating bar 11 is attached to a drive mechanism 12 installed on a base 10.

The drive mechanism 12 moves four chucks 8A, 8B, 8C, and 8D attached to the operating bar 11 simultaneously in the x, y, and z directions along the same trajectory, and supplies the container 1 that is suctioned and held by the chuck 8A. From the conveyor 2 to the first electronic balance 3, the empty weighed container l is transferred by the chuck 8B from the first electronic balance 3 to the powder filling machine 4, and by the chuck 8C, the container 1 after being filled with powder is transferred from the powder filling machine 4 to the second electronic balance. To the balance 5, from the second electronic balance 5 to the defective product ejection device 6 by the chuck FD
The four containers are simultaneously transported by one container transport device 9.

The powder filling machine 4 used in this device is an auger screw filling machine as shown in FIG.
An auger screw 24 rotated by a drive device 23 passes the powder 22 into the container 2'A1 through a screen 25 and a skirt 26 in accordance with the rotation of the auger screw 24.
The specified amount is filled inside. Above auger screw 24
As the drive device 23, a pulse setting type servo moke is used. For example, for one container, 200
Rotate the auger screw 24 4 times with 00 pulses,
The setting is such that 0 mg of powder is filled into container l.

As described above, in this apparatus, the first electronic balance 3 weighs the empty containers for all the containers, and the 21st! The containers after being filled with powder are weighed using the secondary balance 5, each weighed value is manually entered into a data processing device (not shown), and the processing device subtracts the amount, thereby calculating the amount of powder filled into all the containers. (net weight) is calculated, that is, all items are weighed.

In the data processing device that calculates the total weight value,
Based on the calculated net weight, the target weight, and the rotational movement pulse (servo motor pulse) of the auger screw L-24 during filling, the servo motor that drives the auger screw 24 is feedback-controlled, and the auger screw 24 is fed back to the container L. The filling amount (net weight) of the powder 22 is controlled so as to be maintained within a certain control range. In addition, there are specific variations in the filling amount depending on the operating mode from the time of starting to the time of stopping the filling machine 4, and therefore the configuration of feedback control is changed depending on the operating mode.

That is, in general, when filling powder with the powder filling machine 4, after a predetermined amount of powder 22 is charged into the funnel 21, the funnel 21 is covered with a cover (not shown) to seal the powder, and the powder is sealed in this state. As described above, by starting the servo motor and rotating the auger screw 24 intermittently, a predetermined amount of the powder 22 is filled in small portions into the containers l that are being conveyed one after another. When the powder 22 charged into the funnel 21 is exhausted, the servo motor is stopped and a predetermined amount of powder is charged into the funnel 21 again. For example, one dose of powder into the funnel 21 is 100 mg each for 1000 containers.
It is filled with powder.

In the auger filling machine 4, the filling amount varies greatly in the initial mode for a certain period from the start of the servo motor, but the variation decreases in the subsequent steady mode, and the variation increases again in the final mode.

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

■Initial mode...feedback control V with n=1
n=Vn-1-Xs/Xn-1 ■Steady mode...feedback control by n-5 Vn=Vn-1lXs/Xav ■Final mode...feedback control by n-1 V
n=Vn-1-Xs/Xn-1 In the above formula, ■=rotational movement amount of the servo motor, n: current time, n-1: previous time, Xs: target filling amount, Xav: average filling amount for 5 times. Therefore, vn: Current pulse rotational movement amount of the servo motor under feedback control Vn-1: Previous pulse rotational movement amount of the servo motor The above initial mode constant mode, steady mode - switching to the final mode is the front side. Based on the mode switching criteria defined in the above, switching is performed when a plurality of consecutive lines reach the criteria.

The reason why the feedback control is set to n=1 for the initial mode and the final mode as described above is because there is a large variation in the filling amount in these modes, so depending on the previous powder filling amount,
This is because if the servo motor is feedback-controlled each time, the powder filling amount for each container can be kept within the target control range in the initial and final modes.

On the other hand, in the steady mode, there is little variation in the filling amount, and if the filling amount is controlled based on the previous powder filling amount, on the other hand, if the filling amount fluctuates due to an unexpected factor, feedback control will be performed based on the data. , there is a problem that the filling amount after control does not fall within the target control range. Therefore, in the steady mode, n=5, and feedback control is performed based on the average value of the previous five fillings.

In addition, in the filling apparatus shown in FIG. 1, for the container filled by the auger filling machine 4, the container whose net weight is calculated by the data processing device after being weighed by the 21st child balance 5 is the container from the previous container. , (n-1) in the above formula is all (
n-2).

The control method of the present invention performs feedback control separately into the above-mentioned initial mode, steady mode, and final mode, the case where the servo motor is driven with constant pulses without feedback control, and the case where the servo motor is not divided into operating modes from start to stop. Experiments were conducted using feedback control with n=1 and n=5 throughout.

In this experiment, the number of filled bottles was 700, and the target filling m was 100.
mg, and the failure standard was set at ±7%.

The above experimental results are shown in Table 1 on the next page, and
The results obtained according to the present invention are shown in FIG. 3, and the results obtained without control are shown in the graph shown in FIG. 4.

(Left below) Effects As is clear from the above explanation, the filling amount control device according to the present invention incorporates a weighing machine consisting of an electronic balance before and after the filling machine in the filling line, which obstructs the productivity of the filling process. Because it is possible to perform a complete weighing without having to
Feedback control of the servo motor for driving the auger screw can be performed based on the total weight. and,
As a tendency for auger filling machines, variations in the filling amount are characterized by the initial, steady, and final stages in the process from the charging time (initial stage) to the final stage. Since the feedback control method is changed based on the definition, feedback control suitable for each mode can be performed. In this way, filling accuracy can be improved throughout, and the occurrence of defective products whose filling amount is outside the above-mentioned control range can be suppressed as much as possible.

[Brief explanation of drawings]

Fig. 1 is an overall perspective view of a powder filling device using the filling amount control device according to the present invention, Fig. 2 is a sectional view of main parts of the powder filling machine, and Fig. 3 is a diagram showing the filling amount controlled by the device of the present invention. FIG. 4 is a diagram for the case where the filling amount is not controlled. L... Container, 2... 3... 1st T1 child balance, 4... 5... 211th child balance, 6... 21... Funnel, 22, 24... Auger screw patent applicant Takeda Pharmaceutical Company Limited Agent: Patent attorney Aoyama Aoyama and two others Supply conveyor, powder filling machine, defective product removal device, powder, Figure 2

Claims (1)

[Scope of Claims] 1. A first electronic balance for weighing empty containers; a filling machine for filling powder, etc. into the container after weighing the empty container; and a second electronic balance for weighing the filled container for weighing after filling. Calculating the net filling amount from the weighing value of the empty container by the electronic balance and the weighing value of the empty container by the first electronic balance and the weighing value of the filled container by the second electronic balance,
The drive of the motor of the filling machine is feedback-controlled based on the net filling amount, the target filling amount, and the motor drive data of the filling machine during the filling operation, and the feedback control is effective for filling when the filling amount has many variations. In the initial and final stages, feedback control is performed for each previous data, and in the steady stage, where there is little variation in the filling amount between the initial and final stages, feedback control is performed based on the average data of multiple consecutive times, such as 5 times including the previous time. 1. A filling amount control device comprising: a data processing device configured as shown in FIG. 2. An auger filling machine using an auger screw rotated by a pulse setting type servo motor is used as the filling machine, and the motor drive data of the auger filling machine is used as the motor drive data of the filling machine when performing the feedback control. The rotational movement pulse of the servo motor is controlled by feedback control using the data of the rotational movement pulse, and the empty container is transferred from the conveying means to the first electronic balance, and from the first electronic balance to the auger filling machine. 2. The filling amount control device according to claim 1, further comprising a conveyance device that holds and automatically conveys the container from the auger filling machine to the second electronic balance and from the second electronic balance to the defective product removal device.