JP2012240788A - Feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feeder capable of correcting an excessive or deficient speed of feeding an object to be fed.SOLUTION: A raw material is allowed to flow out of an outflow port 41 disposed on the bottom of a feed hopper 4 so that it can be fed into a scale hopper 3 by the action of an auger screw 7. The auger screw 7 is driven by a torque outputted from a feed motor 8. Feed speed variation control is carried out during an operation for feeding a raw material into the scale hopper 3 to change the magnitude of the torque outputted from the feed motor 8. If the magnitude of the torque changes, the state of the action of the auger screw 7 changes, thereby causing the feed hopper 4 to vibrate. Even if a bridge and a rat hole are formed in the feed hopper 4, they are eliminated by virtue of the vibration of the feed hopper 4.

Description

  The present invention relates to a supply machine that supplies a supply object such as a raw material of a resin molded product to a supply target machine such as a weighing hopper.

  For example, a metering supply device that measures the raw material of a resin molded product and supplies a predetermined amount of raw material to a molding machine or the like is known.

  For example, a measuring device including a storage hopper in which raw materials (powder particles) are stored and a measuring hopper for measuring raw materials supplied from the storage hopper is known. The weighing hopper is provided with a load cell. When the raw material is supplied from the storage hopper to the weighing hopper, the mass (weight) of the supplied raw material is measured by the load cell. When a constant mass (fixed amount) of raw material is supplied to the weighing hopper, the supply of the raw material from the storage hopper to the measuring hopper is stopped. Thereafter, the raw material in the weighing hopper is sent to a molding machine or the like.

  The storage hopper is provided with, for example, a screw feeder for supplying raw materials to the weighing hopper. The screw feeder includes a supply cylinder part extending substantially horizontally, a screw disposed in the supply cylinder part, and a motor for rotating the screw. The raw material in the storage hopper flows into the supply cylinder part. When the motor is turned on, the screw rotates and the screw feeds the raw material toward the supply port through the supply cylinder. The raw material that has reached the supply port of the supply cylinder part falls from the supply port and is supplied to the weighing hopper.

JP 2002-318152 A

  However, the material supply speed (supply flow rate) from the storage hopper to the weighing hopper may become unstable. In particular, when the screw (motor) is started, the material supply speed from the storage hopper to the weighing hopper is often too low or too high.

  The objective of this invention is providing the feeder which can eliminate the excess and deficiency state of the supply speed of a to-be-supplied material.

  In order to achieve the above-mentioned object, the present invention operates in a feeder with a hopper that accommodates an article to be supplied and has an outlet at the bottom, a drive source that outputs torque, and a torque from the drive source, A supply means for supplying the supply object from the outlet of the hopper and supplying the supply object machine, and a torque output from the drive source during the supply operation of the supply object to the supply object machine is varied. And vibration control means for vibrating the hopper.

  The material to be supplied is accommodated in a hopper. By the operation of the supply means, the material to be supplied flows out from the outlet provided at the bottom of the hopper. And the to-be-supplied material which flowed out of the hopper is supplied to a supply object machine. The supply means operates by torque output from the drive source.

  When the fluidity of the material to be fed is low, for example, in the hopper, a phenomenon that the material to be solidified in a state where a cavity is formed in the vicinity of the outlet, so-called bridge (arching) occurs, or the material to be supplied from above the outlet There may be a phenomenon where things disappear, so-called rat holes. When such a phenomenon occurs, the outflow amount of the supply from the outlet becomes too small, and the supply speed (supply flow rate) of the supply to the supply target machine becomes too small.

  Therefore, in this supply machine, the magnitude of the torque output from the drive source is changed during the supply operation of the supply object to the supply target machine. When the magnitude of the torque varies, the operating state of the supply means varies and the hopper vibrates. Even if bridges or ratholes occur in the hopper, these phenomena are eliminated by the vibration of the hopper. As a result, the material to be supplied can be satisfactorily discharged from the outlet, and an excessive state of the supply rate of the material to be supplied can be eliminated. Therefore, the supply speed of the supply object to the supply target machine can be stabilized.

  The supply means may be provided below the outflow port, and may be provided with a screw that rotates around the shaft by torque from the drive source and feeds the supply object to one side in the axial direction by the rotation. You may provide the gate which opens and closes an outflow port with the torque from a source.

  The variation in torque output from the drive source may be achieved by intermittently turning on the drive source and changing its on time.

  Further, when the drive source is a motor, the fluctuation in torque output from the drive source is achieved by intermittently turning on the drive source and changing the target rotational speed of the drive source at the time of on. May be.

  When the fluidity of the supply is high, the supply speed (supply flow rate) of the supply to the supply target machine may be excessive.

  By intermittently turning on the drive source, the supply speed of the supply object can be reduced. As a result, an excessive state of the supply rate of the supply object to the supply target machine can be eliminated, and the supply rate can be stabilized.

  According to the present invention, it is possible to eliminate an excessive or insufficient state of the supply rate of the supply object and to stabilize the supply rate.

FIG. 1 is a schematic cross-sectional view of a metering supply device including a feeder according to an embodiment of the present invention. FIG. 2 is a block diagram showing an electrical configuration of the metering device. FIG. 3 is a flowchart showing the flow of control of the feed motor when the raw material is supplied from the feeder to the weighing hopper. FIG. 4 is a timing chart showing a change in ON / OFF of the feed motor during the supply amount fluctuation control, and shows a first setting example of the ON time. FIG. 5 is a timing chart showing a change in ON / OFF of the feed motor during the supply amount fluctuation control, and shows a second setting example of the ON time. FIG. 6 is a timing chart showing the on / off change of the feed motor during the supply amount fluctuation control, and shows a third setting example of the on time. FIG. 7 is a timing chart showing a change in ON / OFF of the feed motor during the supply amount fluctuation control, and shows a fourth setting example of the ON time. FIG. 8 is a timing chart showing a change in ON / OFF of the feed motor during the supply amount fluctuation control, and shows a first setting example of the target rotation speed at the ON time. FIG. 9 is a timing chart showing the on / off change of the feed motor during the supply amount fluctuation control, and shows a second setting example of the target rotation speed at the on time. FIG. 10 is a timing chart showing the on / off change of the feed motor during the supply amount fluctuation control, and shows a third setting example of the target rotation speed at the on time. FIG. 11 is a timing chart showing the on / off change of the feed motor during the supply amount fluctuation control, and shows a fourth setting example of the target rotation speed at the on time. FIG. 12 is a schematic cross-sectional view of a metering supply device including a feeder according to a modification of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic cross-sectional view of a metering supply device including a feeder according to an embodiment of the present invention.

  The metering device 1 is connected to a molding machine (not shown), for example. In the metering device 1, the raw material of the resin molded product is weighed and a fixed amount of raw material is prepared. Then, a fixed amount of raw material is supplied (transported) from the metering device 1 to the molding machine, and a resin molded product made of the raw material is manufactured in the molding machine.

  The metering supply device 1 is provided with a feeder 2 and a weighing hopper 3 (an example of a machine to be fed) that receives the supply of the raw material that is the supply object from the feeder 2.

  The feeder 2 includes a supply hopper 4 (an example of a hopper). The supply hopper 4 has a container shape and can store a raw material therein. The lower portion of the supply hopper 4 is formed in a conical shape that tapers downward. An outlet 41 is formed at the bottom of the supply hopper 4.

  The screw feeder 5 is connected to the outlet 41. The screw feeder 5 includes a supply pipe 6, an auger screw 7 (an example of a supply unit), and a feed motor 8 (an example of a drive source).

  The supply pipe 6 extends in a substantially horizontal direction below the supply hopper 4. One end of the supply pipe 6 is connected to the lower end of the supply hopper 4, and the supply pipe 6 communicates with the supply hopper 4. Therefore, the raw material stored in the supply hopper 4 flows into the supply pipe 6 from the supply hopper 4 due to its own weight. The other end portion of the supply pipe 6 is bent downward, and a drop port 9 is formed on the other end surface facing downward.

  The auger screw 7 has a configuration in which spiral blades are formed around an auger shaft extending on the central axis of the supply pipe 6.

  The output shaft of the feed motor 8 is connected to one end of the auger screw 7.

  The auger screw 7 is rotated by the torque of the feed motor 8. By the rotation of the auger screw 7, the raw material is sent through the supply pipe 6 toward the drop port 9. The raw material that has reached the other end of the supply pipe 6 falls from the drop port 9.

  The raw material falling from the dropping port 9 is received by the weighing hopper 3. The lower portion of the weighing hopper 3 is formed in a conical shape that tapers downward.

  A gate shutter 10 is provided at the lower end of the weighing hopper 3. When the gate shutter 10 is opened, the raw material is discharged from the weighing hopper 3, and when the gate shutter 10 is closed, the discharge of the raw material from the measuring hopper 3 is stopped. In the state where the gate shutter 10 is closed, the raw material falling from the dropping port 9 is received by the weighing hopper 3, whereby the raw material is stored in the weighing hopper 3.

  The weighing hopper 3 is provided with a load cell 11 for measuring the mass of the raw material stored in the weighing hopper 3.

  FIG. 2 is a block diagram showing an electrical configuration of the metering device.

  The metering supply device 1 (feeder 2) includes a control unit 21 (an example of a vibration control unit) formed of a microcomputer including a CPU, a RAM, a ROM, and the like.

  A detection signal for the load cell 11 is input to the control unit 21.

  The control unit 21 is connected to the feed motor 8 via the power supply circuit 22. The power feeding circuit 22 includes an inverter circuit.

  The control unit 21 can rotate the feed motor 8 at a target rotation speed by controlling on / off of the switching element of the power feeding circuit 22 (inverter circuit).

  FIG. 3 is a flowchart showing the flow of control of the feed motor when the raw material is supplied from the feeder to the weighing hopper. FIG. 4 is a timing chart showing ON / OFF changes of the feed motor during the supply amount fluctuation control shown in FIG.

  When the raw material is supplied from the feeder 2 to the weighing hopper 3, the feed motor 8 is turned on (step S1). When the feed motor 8 is turned on, the auger screw 7 starts to rotate. By rotation of the auger screw 7, the raw material is fed toward the dropping port 9 in the supply pipe 6. Thereby, the raw material falls into the weighing hopper 3 through the dropping port 9, and the raw material in the supply hopper 4 flows into the supply pipe 6.

  After the feed motor 8 is turned on, the elapsed time from the turn-on is measured. When a certain time has elapsed after the feed motor 8 is turned on (YES in step S2), control for forcibly changing the supply speed of the raw material (supply speed fluctuation control) is executed (step S3).

In the supply speed variation control, as shown in FIG. 4, the feed motor 8 is controlled so that the feed motor 8 operates in a time-division proportional manner (ON / OFF of the switching element included in the power feeding circuit 22 is controlled). Specifically, the feed motor 8 is turned on (a drive current is supplied from the power supply circuit 22 to the feed motor 8) for a time T _{ON (n)} (n: natural number) in a constant control cycle (proportional cycle) T _0. The feed motor 8 is turned off for the remaining time T _{OFF (n)} in the proportional cycle T ₀ .

The time during which the feed motor 8 is turned on (hereinafter referred to as “on time”) T _{ON (n)} is set to become longer as the supply speed fluctuation control proceeds. For example, the ON time T _{ON (1)} is a predetermined value, and the ON time T _{ON (n)} is a constant coefficient for the _ON time T _{ON (n−1)} of the feed motor 8 one control cycle before. It is set to a value multiplied by (for example, 1.1).

As the feed motor 8 is turned on / off, the magnitude of the torque output from the feed motor 8 varies. In addition, the feed rate of the raw material due to the rotation of the auger screw 7 is rapidly reduced to a value obtained by multiplying the value of the feed rate before the start of the feed rate variation control by T _{ON (1)} / T _0. Ascend as you go. As a result, the supply hopper 4 and the supply pipe 6 are vibrated.

The supply speed fluctuation control is executed over five control cycles (T ₀ × 5).

  After the supply speed fluctuation control is completed, the feed motor 8 is continuously turned on.

  While the raw material is being supplied from the feeder 2 to the weighing hopper 3, the output of the load cell 11 is constantly monitored by the control unit 21, and whether or not a predetermined amount of raw material has been supplied into the measuring hopper 3. Are repeatedly examined (step S4).

  While the mass of the raw material in the weighing hopper 3 has not reached the fixed amount, it is determined that the supply of the raw material to the weighing hopper 3 is not completed (NO in step S4), and the feed motor 8 is continuously turned on. .

  Further, while the raw material is being supplied from the feeder 2 to the weighing hopper 3, the increasing speed of the mass of the raw material in the weighing hopper 3 is within a certain speed range based on the output of the load cell 11 by the control unit 21. Whether or not is repeatedly checked (step S5).

  If the increasing speed of the mass of the raw material in the weighing hopper 3 is within a certain speed range, it is determined that it is not necessary to execute the supply speed fluctuation control (NO in step S5), and the feed motor 8 is continuously on continuously. Is done.

  On the other hand, if the increasing speed of the mass of the raw material in the weighing hopper 3 is out of a certain speed range, it is determined that the supply speed fluctuation control needs to be executed (YES in step S5), and the above-described supply speed fluctuation is determined. Control is executed (step S3).

  When the mass of the raw material in the weighing hopper 3 reaches a fixed amount, it is determined that the supply of the raw material to the weighing hopper 3 is complete (YES in step S4), and the feed motor 8 is turned off (step S6).

  As described above, the raw material is accommodated in the supply hopper 4. By the operation of the auger screw 7, the raw material flows out from an outlet 41 provided at the bottom of the supply hopper 4. The raw material flowing out of the supply hopper 4 is supplied to the weighing hopper 3. The auger screw 7 is operated by torque output from the feed motor 8.

  When the flowability of the raw material is low, for example, a phenomenon in which the raw material is solidified in a state where a cavity is formed in the vicinity of the outlet 41 in the supply hopper 4, a so-called bridge (arching) occurs, or the raw material flows from above the outlet 41 The phenomenon of disappearing, so-called rat hole may occur. When such a phenomenon occurs, the outflow amount of the raw material from the outlet 41 becomes too small, and the supply speed (supply flow rate) of the raw material to the measuring hopper 3 becomes too small.

  Therefore, in the feeder 2, the supply speed fluctuation control is executed during the operation of supplying the raw material to the weighing hopper 3, and the magnitude of the torque output from the feed motor 8 is changed. When the magnitude of the torque changes, the operating state of the auger screw 7 changes and the supply hopper 4 vibrates. Even if a bridge or a rathole is generated in the supply hopper 4, those phenomena are eliminated by the vibration of the supply hopper 4. As a result, the raw material can be satisfactorily flowed out from the outlet 41, and the state where the raw material supply speed is too low can be solved. Therefore, the supply speed of the raw material to the weighing hopper 3 can be stabilized.

  In addition, when the raw material has high fluidity, the supply speed (supply flow rate) of the raw material to the weighing hopper 3 may be excessive.

  In the supply speed fluctuation control, the feed motor 8 is intermittently turned on, so that the raw material supply speed can be reduced. As a result, an excessive state of the supply rate of the raw material to the weighing hopper 3 can be eliminated, and the supply rate can be stabilized.

In the above-described supply speed fluctuation control, the ON time T _{ON (n)} of the feed motor 8 is set to become longer as the control proceeds. However, the ON time T _{ON (n)} may be set as shown in FIGS.

In the setting example shown in FIG. 5, the ON time T _{ON (n)} is set so as to become shorter as the supply speed fluctuation control proceeds. Specifically, the ON time T _{ON (n)} is a value obtained by multiplying the _ON time T _{ON (n−1)} of the feed motor 8 one control cycle before by a certain coefficient (for example, 0.9) less than 1. May be set. In this case, the raw material supply speed by the rotation of the auger screw 7 decreases as the control proceeds from the supply speed before the start of the supply speed fluctuation control.

In the setting example shown in FIG. 6, the ON time T _{ON (n)} has the relationship T _{ON (1)} > T _{ON (2)} > T _{ON (3)} <T _{ON (4)} <T _{ON (5)} . Set to meet.

In the setting example shown in FIG. 7, the ON time T _{ON (n)} has the relationship T _{ON (1)} <T _{ON (2)} <T _{ON (3)} > T _{ON (4)} > T _{ON (5)} . Set to meet.

In the above-described supply speed variation control, the feed motor 8 is intermittently turned on, and each on-time T _{ON (n)} is changed, whereby the torque output from the feed motor 8 and the supply speed of the raw material are changed. Is changed. However, as shown in FIGS. 8, 9, 10, and 11, when the feed motor 8 is intermittently turned on and the target rotational speed of the feed motor 8 at each on time (control cycle) is changed, The torque output from the feed motor 8 and the material supply speed may be changed.

That is, as shown in FIG. 8, the ON time T _ON of the feed motor 8 in each control cycle is set to a constant value (for example, a value that is 1/2 of the control cycle T ₀ ), and the target rotation of the feed motor 8 is set. The speed R _(n) (n: natural number) may be set to increase as the supply speed fluctuation control proceeds.

Further, as shown in FIG. 9, the ON time T _ON of the feed motor 8 in each control cycle is set to a constant value (for example, a value half of the control cycle T ₀ ), and the target rotation of the feed motor 8 is set. The speed R _(n) may be set to decrease as the supply speed fluctuation control proceeds.

Furthermore, as shown in FIG. 10, the ON time T _ON of the feed motor 8 in each control cycle is set to a constant value (for example, a value that is 1/2 of the control cycle T ₀ ), and the target of the feed motor 8 is set. The rotational speed R _(n) may be set so as to satisfy the relationship of R ₍₁₎ > R ₍₂₎ > R ₍₃₎ <R ₍₄₎ <R ₍₅₎ .

Further, as shown in FIG. 11, the ON time T _ON of the feed motor 8 in each control cycle is set to a constant value (for example, a value that is 1/2 of the control cycle T ₀ ), and the target rotation of the feed motor 8 is set. The speed R _(n) may be set so as to satisfy the relationship of R ₍₁₎ <R ₍₂₎ <R ₍₃₎ > R ₍₄₎ > R ₍₅₎ .

  As shown in FIG. 12, the feeder 2 may be provided with a gate 51 that opens and closes the outlet 41 by torque from a motor 52 (an example of a drive source) instead of the screw feeder 5. In this case, the motor 52 may be turned on intermittently, and the on-time may be changed to change the torque output from the motor 52 and the material supply speed.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims. For example, vibration means for vibrating the supply hopper 4 may be provided separately, and on / off of the vibration means may be linked with on / off of the feed motor 8 (or the motor 52).

2 Supply machine 3 Weighing hopper (an example of supply target machine)
4 Supply hopper (an example of a hopper)
7 Auger screw (an example of supply means)
8 Feed motor (example of drive source)
21 Control unit (an example of vibration control means)
22 Power supply circuit (an example of vibration control means)
51 Gate 52 Motor (Example of drive source)

Claims (5)

A hopper that accommodates the supply and has an outlet at the bottom;
A drive source that outputs torque;
A supply means that operates by torque from the drive source, and supplies the supply object to the supply target machine by flowing out the supply object from the outlet of the hopper;
A supply machine comprising: vibration control means for changing the torque output from the drive source to vibrate the hopper during the supply operation of the supply object to the supply target machine.   The said supply means is arrange | positioned under the said outflow port, It rotates about an axis | shaft with the torque from the said drive source, and is provided with the screw which sends a to-be-supplied material to the one side of an axial direction by the rotation. The feeding machine described in.   The supply device according to claim 1, wherein the supply unit includes a gate that opens and closes the outflow port using torque from the drive source.   The said vibration control means changes the torque output from the said drive source by turning on the said drive source intermittently, and changing the ON time, The method as described in any one of Claims 1-3. Feeding machine. The drive source is a motor;
The said vibration control means changes the torque output from the said drive source by turning on the said drive source intermittently and changing the target rotational speed of the said drive source at the time of ON. The feeder according to any one of the above.

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