JP5954772B2 - Control method and apparatus of powder filling machine - Google Patents

Description

  This invention relates to a powder filling machine for discharging powder particles supplied in a filling cylinder by rotation of an auger screw and filling a packaging bag, packaging container or the like in a fixed amount, and a servo motor for rotationally driving an auger screw. The present invention relates to a control method and a control device for executing the control method.

  This type of auger screw type powder filling machine performs filling by rotating the auger screw in the filling cylinder a predetermined number of times for each filling cycle, and discharging a fixed amount of powder from the discharge port at the lower end of the filling cylinder. Is. More specifically, the auger screw has a spiral wing, and the wing is rotated in a filling cylinder filled with the powder, so that the frictional resistance with the powder becomes very large at this time. . Although a servo motor with sufficient torque performance to overcome the frictional resistance of the granular material is used to drive the auger screw, if you try to force the auger screw to rotate with too much load, A so-called powder biting phenomenon occurs, and in an extreme case, the machine is damaged or the granular material is crushed.

  For this reason, a technique for detecting that an excessive load has occurred in the rotation of the auger screw has been disclosed, and the present applicant has also disclosed a similar technique in Patent Document 1, but these conventional techniques are disclosed. We have developed a control method and device that can achieve the same purpose with a new configuration different from the above.

JP 2002-104339 A

That is, a first object of the present invention is to provide a control method and an apparatus having a configuration different from the prior art for detecting an overload acting on an auger screw and quickly stopping the rotation of the auger screw. There is.
A second object of the present invention is to provide a control method and an apparatus for detecting a load shortage acting on an auger screw and quickly stopping the rotation of the auger screw.

In order to achieve the above object, the control method of the present invention comprises:
A filling cylinder in which the powder is supplied into the hollow portion;
An auger screw arranged coaxially in the hollow part of the filling cylinder;
A servo motor that rotationally drives the auger screw;
An encoder that detects the rotation angle position from the origin with respect to the rotation axis of the servo motor;
A method of controlling a powder and particle filling machine comprising:
The following requirements (a) to (c) are included.
(A) Torque control of the servo motor with the command torque, the auger screw is rotated at a preset rotation speed pattern, and a predetermined amount of powder particles are discharged from the filling cylinder during one cycle operation.
(B) The granular material transfer torque that varies with the change in the resistance force that the auger screw receives from the granular material in the filling cylinder is calculated based on the rotational angle position detected by the encoder.
(C) When the calculated powder transport torque value or the integrated value of the powder transport torque during one cycle operation exceeds a preset upper limit threshold value, the servo motor is stopped.

In this way, the overload acting on the auger screw is detected with the value of the granular material transfer torque or the integrated value during one cycle operation of the granular material transfer torque, and the rotation of the auger screw is immediately stopped. Can do. Here, “one-cycle operation” means that “a package is arranged below the filling cylinder, the auger screw is rotated to fill the powder, and then the amount of filling of the powder is constant. It is self-evident that it is the “operation period until the rotation of the auger screw is stopped when the value reaches the value“.

In the said requirement (b), a granular material transfer torque can be calculated based on the requirements of following (b-1)-(b-3), for example.
(B-1) The acceleration of the auger screw is calculated from the rotation angle position detected by the encoder.
(B-2) The acceleration torque is calculated by multiplying the calculated acceleration of the auger screw by the moment of inertia acting on the auger screw.
(B-3) The granular material transfer torque is determined based on a value obtained by subtracting the calculated acceleration torque from the command torque corresponding to the rotation angle position detected by the encoder.

  For the requirement (b-3), for example, a value obtained by subtracting the calculated acceleration torque from the command torque corresponding to the rotation angle position detected by the encoder can be set as the granular material transfer torque.

Further, as a method including the following requirements (b-4) and (b-5),
The above requirement (b-3) is obtained by subtracting values obtained by subtracting the calculated acceleration torque, the calculated dynamic friction torque, and the calculated viscosity torque from the command torque corresponding to the rotation angle position detected by the encoder. It is good also as a granular material transfer torque.
(B-4) The dynamic friction torque required to rotate the auger screw against the structural dynamic friction force received by the auger screw is calculated.
(B-5) The viscous torque required to rotate the auger screw against the structural viscosity received by the auger screw is calculated.

  The moment of inertia is, for example, controlling the servo motor with a constant torque in a state in which the granular material is not supplied to the filling cylinder, and calculating the acceleration of the auger screw from the rotation angle position detected by the encoder. It can be obtained by dividing the acceleration from the torque.

The dynamic friction torque and the viscous torque can be calculated based on the following requirements (d) and (e), for example.
(D) The rotation speed of the auger screw is changed stepwise in a state in which the granular material is not supplied to the filling cylinder, and the command torque at each rotation speed is sampled.
(E) The dynamic friction torque and the viscous torque are calculated based on simultaneous equations obtained by substituting the value of each rotational speed and the value of the command torque sampled for each rotational speed into the following relational expression.
f = (D × V) + b
Here, f is the command torque, D is the viscous load coefficient, V is the rotational speed of the auger screw, (D × V) is the viscous torque, and b is the dynamic friction torque.

In the above-described control method of the powder filling machine,
The upper threshold value is preferably set to the upper limit value of the load acting on the auger screw set in advance for each granular material to be supplied.

Furthermore, in the control method of the above-described powder filling machine,
The lower limit value of the load acting on the auger screw set in advance for each granular material to be supplied is set as the lower limit threshold value,
The servo motor can also be stopped when the value of the calculated granular material transfer torque or the integrated value of the granular material transfer torque during one cycle operation becomes lower than the lower limit threshold value.

  Accordingly, it is possible to detect the load shortage acting on the auger screw with the value of the granular material transfer torque or the integrated value during one cycle operation of the granular material transfer torque, and quickly stop the rotation of the auger screw. it can.

Next, the control device of the present invention
A filling cylinder in which the powder is supplied into the hollow portion;
An auger screw arranged coaxially in the hollow part of the filling cylinder;
A servo motor that rotationally drives the auger screw;
An encoder that detects the rotation angle position from the origin with respect to the rotation axis of the servo motor;
A control device for a powder filling machine comprising:
The servo motor is controlled by executing the control method of the present invention described above.

Furthermore, the control device of the present invention provides:
Comprising means for detecting electrical continuity between the auger screw and the filling cylinder;
The value of the powder particle transfer torque or the integrated value during one cycle operation of the particle particle transfer torque when electrical conduction occurs between the auger screw and the filling cylinder is set as the upper limit threshold value. It is good also as composition to do.

Further, the control device of the present invention is provided with a funnel below the filling cylinder, and provided with a powder upper surface height monitoring means for monitoring the upper surface height of the powder discharged from the filling cylinder and collected in the funnel,
Based on the upper surface height of the granular material monitored by the granular material upper surface height monitoring means, including a configuration that stops the rotation of the servo motor when the upper surface height of the granular material reaches a preset value. You can also.

According to the above-described invention, the overload acting on the auger screw is detected with the value of the granular material transfer torque or the integrated value during one cycle operation of the granular material transfer torque, and the auger screw is quickly rotated. Can be stopped.
Further, it is possible to detect the load shortage acting on the auger screw with the value of the granular material transfer torque or the integrated value during one cycle operation of the granular material transfer torque, and to quickly stop the rotation of the auger screw. .

It is a block diagram which shows the outline | summary of the granular material filling machine with which the control apparatus which concerns on embodiment of this invention was integrated. It is a functional block diagram of a granular material transfer torque output part. It is a graph which shows the relationship between the rotational speed pattern of an auger screw, and a granular material transfer torque. It is a functional block diagram of the granular material transfer torque calculating part which concerns on other embodiment. It is the graph which calculated | required the relationship between the rotational speed of an auger screw, command torque, viscous torque, and dynamic friction torque on the assumption that the viscous load coefficient D = 0.0013. It is a block diagram for demonstrating the structure of the control apparatus provided with the contact detection means of the auger screw to a filling cylinder. It is a block diagram which shows the example of application of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Outline of powder filling machine]
FIG. 1 is a configuration diagram showing an outline of a powder filling machine in which a control device according to an embodiment of the present invention is incorporated.
As shown in the figure, in the powder filling machine, a cylindrical filling cylinder 11 is connected to the center of the bottom of a funnel-shaped hopper 10, and an auger screw 12 is coaxially installed in the hollow portion of the filling cylinder 11. It is arranged in. The powder body is supplied to the hopper 10 from the opening on the upper surface. Then, the granular material stored in the hopper 10 is supplied from above into the hollow portion of the filling cylinder 11, and the granular material is transferred downward within the hollow portion of the filling cylinder 11 as the auger screw 12 rotates. It discharges from the discharge outlet 11a opened to the lower end of the. A packaging body 1 (packaging bag, packaging container, or the like) is disposed below the filling cylinder 11, and the powder body is quantitatively filled into the packaging body 1.

  The auger screw 12 has a structure having a spiral wing on the peripheral surface of a rod-shaped auger shaft. The upper end of the auger screw 12 is connected to a rotating shaft 20 a of the servo motor 20 and is rotated by the servo motor 20.

  The servo motor 20 is torque controlled and is driven and controlled by a command torque from the control device 30. The command torque is a control torque signal for rotating the auger screw 12 with a preset rotation speed pattern and discharging a predetermined amount of powder particles from the filling cylinder 11 during one cycle operation. This command torque is obtained from the rotation amount and rotation speed pattern of the auger screw 12 for each granular material to be supplied, and is stored in advance in a storage unit (not shown) of the control device 30.

  In addition, an encoder 40 is attached to the servo motor 20. The encoder 40 detects the rotational angle position from the origin with respect to the rotating shaft 20a of the servo motor 20, and outputs the detection signal.

[Function of the control device 30]
The control device 30 includes an operation control unit 50, a granular material transfer torque output unit 60, and a granular material transfer torque abnormality determination unit 70.
The operation control unit 50 outputs a command torque to the servo motor 20 so as to rotate the auger screw 12 with a predetermined rotation amount and rotation speed pattern. The servo motor 20 is feedback controlled by a detection signal from the encoder 40. The command torque from the operation control unit 50 is also sent to the granular material transfer torque output unit 60. The granular material transfer torque output unit 60 receives a detection signal from the encoder 40.

FIG. 2 is a functional block diagram of the granular material transfer torque output unit 60. It should be noted that viscous resistance (viscous torque) and dynamic friction force (dynamic friction torque) act on the auger screw 12 due to structural factors, but in this embodiment shown in the figure, the influence of the viscous torque and the dynamic friction torque is omitted. Yes.
In the present embodiment, the torque necessary for the auger screw 12 to discharge the granular material in the filling cylinder 11 is defined as the granular material transfer torque, and the rotational angle position at which this granular material transfer torque is input from the encoder 40. And the command torque input from the operation control unit 50.
Here, as shown in FIG. 2, the granular material transfer torque output unit 60 is further added to each functional block of a speed calculation unit 61, an acceleration calculation unit 62, an acceleration torque calculation unit 63, and a granular material transfer torque calculation unit 64. The function of the powder particle transfer torque output unit 60 will be described separately. That is, the granular material transfer torque output unit 60 calculates the speed of the auger screw 12 by differentiating the rotation angle position input from the encoder 40 by the speed calculation unit 61. Next, the acceleration calculator 62 further differentiates the speed of the auger screw 12 to calculate the acceleration (angular acceleration) of the auger screw 12. Subsequently, the acceleration torque calculation unit 63 calculates the acceleration torque of the auger screw 12 by multiplying the acceleration (angular acceleration) of the auger screw 12 by the inertia moment acting on the auger screw 12.
Here, the acceleration torque is a torque required to rotate the auger screw 12 itself when the influence of the viscous torque and the dynamic friction torque is omitted in a state where the powder and granular materials are not supplied. 20 and the auger screw 12 and the like are obtained from the moment of inertia and acceleration of the rotation mechanism itself. The value of the moment of inertia used when calculating the acceleration torque is obtained by experiments as will be described later, and is stored in advance in a storage unit (not shown) of the control device 30.

In this embodiment (an embodiment in which the influence of viscous torque and dynamic friction torque is omitted), the torque for rotating the auger screw 12 itself is subtracted from the command torque output to the servo motor 20 that rotationally drives the auger screw 12. Torque is the torque (powder transfer torque) used to discharge the powder. That is, the granular material transfer torque calculation unit 64 uses the value obtained by subtracting the calculated acceleration torque value from the command torque value output from the operation control unit 50 as the granular material transfer torque. Is calculated.
The granular material transfer torque calculated by the granular material transfer torque calculating unit 64 is output to the granular material transfer torque abnormality determining unit 70 (see FIG. 1).

FIG. 3 is a graph showing the relationship between the rotational speed pattern of the auger screw 12 and the granular material transfer torque.
When the load that the auger screw 12 receives from the granular material is substantially constant, the command torque and the acceleration torque change approximately proportionally according to the rotational speed pattern of the auger screw 12, and therefore the granular material transfer torque output unit 60 As shown by Ta1 in FIG. 3, the powder and particle transfer torque calculated in (1) does not vary greatly and falls within a certain range. In addition, in a state in which the granular material is not supplied to the filling cylinder 11, since the auger screw 12 is not subjected to a load from the granular material, the acceleration torque becomes almost the same value as the command torque, and the granular material transfer torque is As shown by Ta0 in FIG. 3, it becomes almost zero.
Even when an excessive load is applied to the auger screw 12 from the granular material, the operation control unit 50 tries to rotate the auger screw 12 at a constant speed by feedback control, so that the command torque increases. The acceleration torque for rotating the auger screw 12 itself is calculated based on the rotation speed based on the detection signal from the encoder 40. Therefore, even if the command torque increases, as long as the auger screw 12 rotates according to a predetermined rotation speed pattern. Then, a value according to the rotation speed pattern is calculated. On the other hand, when the change in the rotational angle position of the auger screw 12 is reduced due to an excessive load from the granular material, the acceleration torque decreases with the change in the rotational angle position. As a result, the granular material transfer torque calculated by subtracting the acceleration torque value from the command torque value shows a locally large value as indicated by Ta2 in FIG.

Returning to FIG. 1, the particulate matter transfer torque abnormality determining unit 70 detects an abnormality in the operation control unit 50 when the value of the particulate matter transfer torque calculated as described above exceeds a preset upper threshold value. Output a signal. The operation control unit 50 stops the servo motor 20 when an abnormality detection signal is input. As a result, when an excessive load is applied to the auger screw 12, the auger screw 12 is forcibly rotated to cause a so-called powder biting phenomenon or the axis of the auger screw 12 is shaken. It is possible to avoid inconveniences that cause machine breakage and crushing of granular materials.
Here, the upper limit threshold value is an upper limit value of the load acting on the auger screw 12, and is obtained by experiment for each granular material to be supplied and stored in advance in a storage unit (not shown) of the control device 30. . The user can arbitrarily determine how much the upper threshold value is set.

[About moment of inertia]
The moment of inertia used when calculating the acceleration torque of the auger screw 12 can be obtained in advance by the following procedure, for example.
That is, the auger screw 12 is rotated by controlling the servo motor 20 with a constant torque in a state where no powder is supplied to the filling cylinder 11. Then, the acceleration of the auger screw 12 is calculated from the rotational angle position detected by the encoder 40, and a value obtained by dividing the acceleration from the constant torque is defined as a moment of inertia.
In order to increase the accuracy of calculating the moment of inertia, it is preferable to repeat the rotational drive of the auger screw 12 many times and use the average value of the values of the moment of inertia obtained by the rotational drive.

[High-precision calculation of powder particle transfer torque]
In the above-described embodiment, the granular material transfer torque is obtained by omitting the influence of the viscous resistance and the dynamic friction force that originally act on the auger screw 12. However, in addition to the acceleration torque, the auger screw 12 has a structural characteristic. Factors such as viscous resistance and dynamic friction force are acting. Therefore, if the powder particle transfer torque is calculated in consideration of the torque against the viscous resistance and the dynamic friction force, it becomes possible to determine the overload acting on the auger screw 12 with higher accuracy.
That is, the command torque is determined based on the premise that it is the sum of acceleration torque, viscosity torque, dynamic friction torque, and powder transport torque.
Here, the viscous torque is torque required to rotate the auger screw 12 against the structural viscosity that the auger screw 12 receives. The dynamic friction torque is a torque necessary for rotating the auger screw 12 against the structural dynamic friction force received by the auger screw 12.

FIG. 4 is a functional block diagram of a granular material transfer torque output unit 60 according to another embodiment configured based on the above premise.
In the embodiment shown in the figure, the granular material transfer torque output unit 60 includes, in addition to the functional blocks of the speed calculation unit 61, the acceleration calculation unit 62, the acceleration torque calculation unit 63, and the granular material transfer torque calculation unit 64, A viscous torque output unit 65 and a dynamic friction torque output unit 66 are included.
The viscous torque output unit 65 is set in advance with a viscous load coefficient obtained through experiments, and the viscous torque corresponding to the speed of the auger screw 12 calculated by the speed calculation unit 61 is used as the granular material transfer torque calculation unit 64. Output to. The dynamic friction torque output unit 66 is preliminarily set with dynamic friction torque obtained through experiments, and outputs this dynamic friction torque to the granular material transfer torque calculation unit 64.

  The granular material transfer torque calculation unit 64 calculates the acceleration torque value calculated by the acceleration torque calculation unit 63 from the command torque value output from the operation control unit 50 when the encoder 40 detects the rotation angle position, and the viscosity. The value of the viscous torque output from the torque output unit 65 and the value of the dynamic friction torque output from the dynamic friction torque output unit 66 are subtracted to calculate the particulate transport torque.

[Calculation of viscous torque and dynamic friction torque]
For the viscous torque and the dynamic friction torque, first, the rotational speed of the auger screw 12 is changed stepwise in a state in which the granular material is not supplied to the filling cylinder 11, and the command torque at each rotational speed is sampled. It can be calculated by simultaneous equations obtained by substituting the value of the rotational speed and the value of the command torque sampled for each rotational speed.
f = (D × V) + b
Here, f is the command torque, D is the viscous load coefficient, V is the rotational speed of the auger screw 12, (D × V) is the viscous torque, and b is the dynamic friction torque.

FIG. 5 is a graph showing the relationship between the rotational speed of the auger screw 12 and the command torque, viscosity torque, and dynamic friction torque, assuming that the viscous load coefficient D is 0.0013.
In the figure, f indicates the command torque, DV indicates the estimated value of the viscous torque, and b indicates the estimated value of the dynamic friction torque. As shown in the figure, the viscous torque DV changes in proportion to the rotational speed V of the auger screw 12. In addition, the dynamic friction torque b varies depending on the rotation speed of the auger screw 12 while the value b _min of the auger screw 12 changes depending on the rotation speed of the auger screw 12, but the value b _max of the high speed area where the rotation speed exceeds a certain value It shows an almost constant value without depending on the speed. Specifically, until the rotational speed of the auger screw 12 approaches 300 rpm, the dynamic friction torque value b _min changes depending on the rotational speed. When the rotational speed exceeds 300 rpm, the dynamic friction torque value b _max converges to a constant value. ing.

Next, a specific example of the procedure for obtaining the viscous torque and the dynamic friction torque will be described.
First, the command torque is measured by changing the rotational speed of the auger screw 12 in steps of 100 rpm from 100 to 800 rpm.
Since it can be seen from FIG. 5 that the viscous load coefficient can be calculated by obtaining the inclination of the auger screw 12 in the high speed range, the command torque when the rotation speed of the auger screw 12 is 400 rpm and 800 rpm is measured, and f = ( The viscous load coefficient Dn is calculated from the simultaneous equations of (D × V) + b. The value of the dynamic friction torque b at that time is a value b _max that converges to a constant value. The gradient Dg of the dynamic friction torque in the low speed region of the auger screw 12 can be obtained by calculating the gradient Dm at 100 rpm and 200 rpm and Dg = Dm−Dn. Since the actual relationship is a curve, the value obtained by this calculation method is an approximate value.
In this way, the viscous torque and the dynamic friction torque are calculated by driving the auger screw 12 at 100 rpm, 200 rpm, 400 pm, and 800 rpm and automatically calculating from the simultaneous equations of f = (D × V) + b. be able to.
A specific calculation example is shown below.
<When the rotation speed of the auger screw 12 is 300 rpm or more>
f4 = Dn × 400 × (2π / 60) + bmax
f8 = Dn × 800 × (2π / 60) + bmax

f8−f4 = Dn × 400 × (2π / 60)
Dn = (f8−f4) / {400 × (2π / 60)}
b _max = f4-Dn × {400 × (2π / 60)}

<When the rotation speed of the auger screw 12 is less than 300 rpm>
f2 = Dm × 200 × (2π / 60) + b _min
f1 = Dm × 100 × (2π / 60) + b _min
Dm = (f2−f1) / {100 × (2π / 60)}

Dg = Dm−Dn
b _min = f2-Dm × 200 × (2π / 60)

[Detection of contact of auger screw 12 to filling cylinder 11]
FIG. 6 is a configuration diagram for explaining the configuration of the control device 30 provided with means for detecting contact of the auger screw 12 with the filling cylinder 11.
The control device 30 shown in the figure includes a continuity detection unit 80. The continuity detection unit 80 has a function of detecting electrical continuity between the auger screw 12 and the filling cylinder 11 and detecting contact of the auger screw 12 with the filling cylinder 11. Generally, the filling cylinder 11 and the auger screw 12 are formed of a metal material. Therefore, when the auger screw 12 swings in the lateral direction due to the overload received from the granular material in the filling cylinder 11 and comes into contact with the inner peripheral surface of the filling cylinder 11, the space between the filling cylinder 11 and the auger screw 12 is electrically connected. It will be in a conductive state. Therefore, a positive voltage is applied to one of the filling cylinder 11 and the auger screw 12, and a negative voltage is applied to the other, and the conduction detecting unit 80 detects electrical conduction when the auger screw 12 contacts the filling cylinder 11. It is configured to detect.

  When the continuity detecting unit 80 detects electrical continuity when the auger screw 12 contacts the filling cylinder 11, the continuity detecting unit 80 outputs a continuity signal to the granular material transfer torque abnormality determining unit 70. The granular material transfer torque abnormality determination unit 70 outputs an abnormality detection signal to the operation control unit 50 when the conduction signal from the conduction detection unit 80 is input. The operation control unit 50 stops the servo motor 20 when an abnormality detection signal is input. As a result, when an excessive load is applied to the auger screw 12, the auger screw 12 is forcibly rotated to cause a so-called powder biting phenomenon, or in extreme cases, damage to the machine or crushing of the granular material. It is possible to avoid inconvenience.

The granular material transfer torque abnormality determining unit 70 has a function of setting and changing the upper threshold value based on the granular material transfer torque when the continuity signal from the continuity detection unit 80 is input. For example, when a continuity signal from the continuity detection unit 80 is input, upper limit is set for the powder transport torque or a value lower than the powder transport torque (for example, a value of about 80% of the powder transport torque). Change the threshold setting.
Thereby, it becomes possible to avoid the trouble that the auger screw 12 swings in the lateral direction due to the overload received from the granular material in the filling cylinder 11 and contacts the inner peripheral surface of the filling cylinder 11.

[Setting of lower limit threshold of load acting on auger screw 12]
In the above-described embodiment, the upper limit threshold value of the granular material transfer torque is set in the granular material transfer torque abnormality determination unit 70 in response to the overload acting on the auger screw 12, but this is not limiting. The lower limit value of the load acting on the auger screw 12 is set as the lower limit threshold value for each granular material to be supplied in the granular material transfer torque abnormality determination unit 70, and is calculated by the granular material transfer torque output unit 60. The servomotor 20 can also be configured to stop when the value of the powder particle transfer torque that has been reduced becomes lower than the lower threshold.

  In a state where the amount of powder supplied to the filling cylinder 11 is insufficient, the load acting on the auger screw 12 is reduced, and accordingly the powder transfer calculated by the powder transfer torque output unit 60 is performed. The torque value may also be reduced. Therefore, when the lower limit threshold is set in the granular material transfer torque abnormality discriminating unit 70 and the value of the granular material transfer torque becomes smaller than the lower limit threshold, insufficient supply of the granular material occurs. And the rotation of the auger screw 12 is immediately stopped. Thereby, generation | occurrence | production of the inferior goods by the insufficient filling of the granular material to the package 1 can be suppressed, and the improvement of a yield can be aimed at.

In addition, this invention is not limited to the structure of embodiment mentioned above, A deformation | transformation implementation or application implementation is possible as needed.
For example, in the above-described embodiment, the servomotor 20 is stopped when the value of the particle transfer torque calculated by the particle transfer torque output unit 60 exceeds the preset upper threshold value. However, the present invention is not limited to this. In other words, the granular material transfer torque abnormality discriminating unit 70 determines whether the integrated value during one cycle operation of the granular material transfer torque exceeds a preset upper threshold value or from a preset lower threshold value. Alternatively, an abnormality detection signal may be output to the operation control unit 50 when the value becomes lower. The operation control unit 50 stops the servo motor 20 when an abnormality detection signal is input.

  Moreover, the value of the granular material transfer torque in the steady state in which the granular material filling operation is performed without any problem and the integrated value in the one-cycle operation are obtained a plurality of times (for example, 10 times), and the average value is obtained. The value obtained by calculating and increasing the average value by a certain percentage (for example, a value of 150% of the average value) is set as the upper threshold, and the average value is decreased by a certain percentage (for example, 50% of the average value). Can be set as the lower threshold.

FIG. 7 is a block diagram showing an application example of the present invention.
As shown in the figure, the powder filling machine is provided with a funnel 91 below the filling cylinder 11 in order to reliably fill the packing 1 with the powder. The granular material discharged from the filling cylinder 11 is supplied to the inside of the funnel 91, falls downward from a discharge port 91 a formed at the lower center of the funnel 91, and is filled inside the packaging body 1. Here, the opening area of the discharge port 91a formed in the funnel 91 is set sufficiently wide so that the granular material stays in the funnel and does not accumulate.
However, when clogging of the granular material occurs in the funnel 91, not only the smooth filling of the packaging body 1 is inhibited, but also the granular material overflows from the funnel 91 and soils the surroundings. there is a possibility.

  Therefore, in the granular material filling machine shown in FIG. 7, a configuration provided with means (powder particle upper surface height monitoring means 90) for monitoring the upper surface height of the granular material discharged from the filling cylinder 11 and collected in the funnel 91. It has become. As the granular material upper surface height monitoring means 90, for example, an optical sensor 92 may be used to detect the upper surface height of the granular material.

  While the granular material supplied into the funnel 91 is normally dropped from the discharge port 91a and filled in the package 1, the upper surface height of the granular material in the funnel 91 is not excessively high. . However, when the funnel 91 is also clogged in the discharge port 91a and an abnormality occurs in which the powder particles are not normally discharged, the upper surface height of the powder particles supplied to the funnel 91 increases. The upper surface height monitoring means 90 of the granular material monitors the upper surface height of the granular material in the funnel 91 rising in this way.

  And the granular material upper surface height monitoring means 90 controls the detection signal which shows clogging of granular material when the upper surface height of the granular material in the funnel 91 exceeds the preset upper limit height. 30 to the operation control unit 50. The operation control unit 50 stops the servo motor 20 when the detection signal from the powder upper surface height monitoring unit 90 is input. As a result, inconvenience associated with clogging of the powder particles in the funnel 90 can be avoided, and the powder particle filling machine can be operated more stably.

In addition, although away from this invention, the structure of the powder filling machine provided with the function of detecting clogging of powder in the funnel is the operation control of the auger screw 12 based on the powder transfer torque (servo motor). 20 drive control) can also be used separately. The configuration of the powder filling machine in that case is as follows.
That is, a filling cylinder in which the powder is supplied into the hollow portion,
An auger screw disposed coaxially in the hollow portion of the filling cylinder;
A servo motor for rotationally driving the auger screw;
An operation control unit for driving and controlling the servo motor;
A funnel provided below the filling cylinder;
The upper surface height of the granular material discharged from the filling cylinder and collected in the funnel is monitored, and when the upper surface height of the granular material reaches a preset value, a detection signal is output to the operation control unit. And a powder body upper surface height monitoring means,
The said operation control part becomes a granular material filling machine of the structure which stops a servomotor, when a detection signal is input from the upper surface height monitoring means of the said granular material.

1: package, 10: hopper, 11: filling cylinder, 12: auger screw,
20: Servo motor, 30: Control device, 40: Encoder, 50: Operation control unit, 60: Powder transport torque output unit, 61: Speed calculation unit, 62: Acceleration calculation unit, 63: Acceleration torque calculation unit, 64 : Granular material transfer torque calculation unit, 65: viscous torque output unit, 66: dynamic friction torque output unit, 70: granular material transfer torque abnormality determination unit, 80: conduction detection unit, 90: granular material upper surface height monitoring means , 91: funnel, 92: optical sensor

Claims (11)

A filling cylinder in which the powder is supplied into the hollow portion;
An auger screw disposed coaxially in the hollow portion of the filling cylinder;
A servo motor for rotationally driving the auger screw;
An encoder that detects a rotational angle position from the origin with respect to the rotational axis of the servo motor;
A method for controlling a granular material filling machine for quantitatively filling a packaging body disposed below the filling cylinder by discharging the granular material from the filling cylinder along with the rotation of the auger screw ,
A control method comprising the following requirements (a) to (c):
(A) Torque-controlling the servomotor with a command torque, rotating the auger screw at a preset rotation speed pattern, and discharging a predetermined amount of powder particles from the filling cylinder during one cycle operation Let
(B) A granular material transfer torque that varies with a change in resistance force that the auger screw receives from the granular material in the filling cylinder is calculated based on the rotational angle position detected by the encoder.
(C) The servo motor is stopped when the value of the calculated particle transport torque or the integrated value of the powder transport torque during one cycle operation exceeds a preset upper limit threshold value. In said requirement (b), the said granular material transfer torque is calculated based on the requirements of following (b-1)-(b-3), The granular material filling described in Claim 1 characterized by the above-mentioned. How to control the machine.
(B-1) The acceleration of the auger screw is calculated from the rotation angle position detected by the encoder.
(B-2) The acceleration torque is calculated by multiplying the calculated acceleration of the auger screw by the moment of inertia acting on the auger screw.
(B-3) The granular material transfer torque is determined based on a value obtained by subtracting the calculated acceleration torque from the command torque corresponding to the rotation angle position detected by the encoder. In the control method of the granular material filling machine according to claim 2,
The requirement (b-3) is characterized in that a value obtained by subtracting the calculated acceleration torque from the command torque corresponding to the rotational angle position detected by the encoder is the powder particle transfer torque. Control method for body filling machine. In the control method of the granular material filling machine according to claim 2, further comprising the following requirements (b-4) and (b-5),
(B-4) The dynamic friction torque required to rotate the auger screw against the structural dynamic friction force received by the auger screw is calculated.
(B-5) Viscosity torque required to rotate the auger screw against the structural viscosity received by the auger screw is calculated.
The requirement (b-3) includes the calculated acceleration torque, the calculated dynamic friction torque, and the calculated viscosity torque from the command torque corresponding to the rotational angle position detected by the encoder, respectively. A method for controlling a granular material filling machine, wherein the subtracted value is used as the granular material transfer torque. In the control method of the granular material filling machine according to any one of claims 2 to 4,
The moment of inertia calculates the acceleration of the auger screw from the rotational angle position detected by the encoder, while controlling the servo motor with a constant torque in a state in which the granular material is not supplied to the filling cylinder. A method for controlling a powder filling machine, wherein the acceleration is obtained by dividing the acceleration from a constant torque. In the control method of the granular material filling machine according to claim 4,
The dynamic friction torque and the viscous torque are calculated based on the following requirements (d) and (e).
(D) The rotational speed of the auger screw is changed stepwise in a state where no powder is supplied to the filling cylinder, and the command torque at each rotational speed is sampled.
(E) Calculate the dynamic friction torque and the viscous torque based on the simultaneous equations obtained by substituting the value of each rotational speed and the value of the command torque sampled for each rotational speed into the following relational expression. To do.
f = (D × V) + b
Here, f is the command torque, D is the viscous load coefficient, V is the rotational speed of the auger screw, (D × V) is the viscous torque, and b is the dynamic friction torque. In the control method of the granular material filling machine according to any one of claims 1 to 6,
The upper limit threshold value is an upper limit value of a load acting on the auger screw set in advance for each granular material to be supplied. In the control method of the granular material filling machine according to any one of claims 1 to 7,
The lower limit value of the load acting on the auger screw set in advance for each granular material to be supplied is set as the lower limit threshold value,
The servomotor is stopped when the value of the calculated particle transfer torque or the integrated value during one cycle operation of the particle transfer torque is lower than the lower limit threshold value. To control the powder filling machine. A filling cylinder in which the powder is supplied into the hollow portion;
An auger screw disposed coaxially in the hollow portion of the filling cylinder;
A servo motor for rotationally driving the auger screw;
An encoder that detects a rotational angle position from the origin with respect to the rotational axis of the servo motor;
A control unit for a powder filling machine that discharges powder particles from the filling cylinder with rotation of the auger screw and quantitatively fills the package disposed below the filling cylinder ,
A control device that controls the servo motor by executing the control method according to claim 1. In the control apparatus of the granular material filling machine according to claim 9,
Means for detecting electrical conduction between the auger screw and the filling cylinder;
When the electrical continuity is generated between the auger screw and the filling cylinder, the upper limit is set to the value of the powder particle transfer torque or the integrated value during one cycle operation of the powder particle transfer torque. A control device for a powder filling machine, characterized in that it is set as a threshold value. In the control device of the granular material filling machine according to claim 9 or 10,
A funnel is provided below the filling cylinder, and a powder upper surface height monitoring means for monitoring the upper surface height of the powder discharged from the filling cylinder and collected in the funnel is provided,
Based on the upper surface height of the granular material monitored by the granular material upper surface height monitoring means, the rotation of the servo motor is stopped when the upper surface height of the granular material reaches a preset value. The control apparatus of the granular material filling machine characterized by including a structure.

Images