JP2020083489A - Control device of bucket conveyor - Google Patents

Abstract

To provide a control device of a bucket conveyor allowing conveyor transportation in a stable manner by preventing conveyor stop caused by a regenerative state during no-load running.SOLUTION: A control device 10 of a bucket conveyor according to the present invention, which is the control device 10 of the bucket conveyor transporting by filling objects to be transported to a plurality of buckets and rotating them between an upper and lower pulleys, is provided with a control unit 30 controlling a driving unit driving a bucket to reduce speed based on a detected value of no-load or low load of the bucket conveyor at a lifting side during transportation.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a lifting bucket conveyor control device capable of continuously transporting granular materials such as coal powder, gypsum powder, and wood powder.

Among devices for transporting powdered particles such as coal powder, gypsum powder, and wood powder, there is a bucket conveyor (also referred to as a bucket elevator) that can be transported in the vertical (vertical) direction (for example, disclosed in Patent Document 1). This device has a pair of pulleys at the top and bottom, a chain (or an endless belt) is attached around the pulleys, and a plurality of buckets are attached to the chain. With such a configuration, the bucket filled with the powder or granular material can be moved by moving in the up and down direction.

表１は、バケットコンベアのコンベアに付着する粉粒体の有無と、無負荷または負荷時における力行又は回生状態を示している。図６は表１のＡ−Ｄのインバータ波形の説明図である。同図の縦軸は負荷率を示し、定常運転時を基準値（点線）とし、横軸は時間ｔを示す（以下図４，５も同じ）。 Among the granular materials to be conveyed, especially gypsum, coal powder, etc. are likely to fly up and adhere to the periphery of the bucket as well as the bucket body. This will increase the weight of the bucket. Further, the bucket main body that slides on the granular material is locally worn, which causes an unbalance of the rotating load of the bucket conveyor.
Here, the power for rotating the bucket conveyor is such that the tension difference before and after the upper pulley is applied as chain tension to rotate the bucket conveyor. When the bucket main body is filled with powdery particles, the chain tension on the lifting side of the bucket always acts (the tension above the unbalanced load acts), so the output shaft torque of the rotating drive device is It always works in the same direction.

Table 1 shows the presence/absence of powder particles adhering to the conveyor of the bucket conveyor and the power running or regenerative state under no load or under load. FIG. 6 is an explanatory diagram of inverter waveforms A to D in Table 1. The vertical axis of the figure shows the load factor, the reference value (dotted line) is used during steady operation, and the horizontal axis shows time t (the same applies to FIGS. 4 and 5 below).

[When loaded]
When the bucket is loaded with the load, the chain tension on the bucket lifting side is always acting. In other words, the tension above the unbalanced load is acting. Always act in the same direction. Therefore, no regenerative force is generated in the drive unit.
At this time, the powering state is set regardless of whether or not there is any adhered substance on the bucket or the like (see A and B in Table 1, FIG. 6(1)).

[Unloaded]
When the bucket is not loaded with the load and no load is applied, when the weight of the bucket increases due to the load of the load and the bucket rotates at high speed, a centrifugal force greater than that before the load is applied near the upper pulley. The centrifugal force on the lifting side reduces the lifting force because a force is generated on the side opposite to the bucket weight on the lifting side. On the other hand, on the return side where the upper pulley is rotated, centrifugal force is added to the weight of the bucket, and the chain tension on the return side increases. Then, in the inverter of the drive unit, the power supply state is changed to the regeneration state. This regenerative power increases as the adhesion of the powder or granular material increases or the rotation speed increases (D in Table 1, see FIG. 6(3)). In addition, when there is no powder or granular material attached to the bucket or the like, the regenerative state is instantaneously obtained, but the power running state is maintained almost (see C in Table 1, FIG. 6(2)).
If the regenerative power exceeds a certain value, the intermediate DC circuit voltage rises, the protective function of the inverter is stopped, and the cargo handling may be hindered. Conventionally, in order to consume (eliminate) this regenerated energy, a separate converter is provided to regenerate the power source by the converter or convert it into thermal energy in the braking resistor.

Japanese Patent No. 4369591

The problem to be solved by the present invention is to provide a bucket conveyor control device capable of stable conveyor conveyance by preventing conveyor stoppage due to a regenerative state during no-load operation in view of the above-mentioned problems of the conventional technology. Especially.

As a first means for solving the above-mentioned problems, the present invention provides a bucket conveyor control device that fills a plurality of buckets with a conveyed object and rotates the upper and lower pulleys for conveyance.
Provided is a bucket conveyor control device including a control unit that performs control to decelerate to a drive unit that drives the bucket based on a no-load or low-load detection value of the lifting-side bucket conveyor that is being conveyed. Especially.
According to the first means, generation of regenerative energy can be suppressed without consuming the regenerative energy by the converter, the control resistor, or the like.

The present invention provides, as a second means for solving the above-mentioned problems, in the first means,
Providing a conveyance amount measurement unit that measures the conveyance amount of the lifting side bucket during conveyance,
A control device for a bucket conveyor, wherein the control unit performs control to decelerate as the no-load or low-load detection value when the detection value of the conveyance amount measurement unit is less than a predetermined conveyance amount. It is in.
According to the second means, it is possible to realize easy and accurate no-load detection by measuring the carry amount. In addition, equipment costs can be reduced. Therefore, more efficient device operation can be continued and productivity is improved.

The present invention provides, as a third means for solving the above-mentioned problems, in the first or second means,
By providing a dead timer to measure a predetermined time from the detection value of the no load or low load,
The controller is to provide a control device for a bucket conveyor, which performs a control for decelerating after a lapse of the predetermined time.
According to the third means, it is possible to prevent recognition of no load or low load due to variations in load shortage.

According to the present invention, generation of regenerative energy can be suppressed without consuming the regenerative energy by the converter, the control resistor, or the like.
Further, by suppressing (decelerating) the speed when there is no load, it becomes possible to suppress mechanical wear of the bucket and the like.

It is a block diagram of the control apparatus of the bucket conveyor of the present invention. It is a processing flow figure of the control device of the bucket conveyor of the present invention. It is a timing chart of the control device of the bucket conveyor of the present invention. It is explanatory drawing of the inverter waveform by the control apparatus of the bucket conveyor of this invention. It is explanatory drawing of the inverter waveform at the time of a load shortage (showing the relationship of load factor time). It is explanatory drawing of the inverter waveform of AD of Table 1 (it shows the time relationship of a load factor).

An embodiment of a bucket conveyor control device of the present invention will be described in detail below with reference to the drawings.
The bucket conveyor has a pair of pulleys arranged above and below a casing, and a chain (or an endless belt) is annularly attached around the pulleys. A plurality of buckets are attached to the chain at equal intervals. A drive unit (for example, a drive motor) directly connected to the upper pulley rotates the upper and lower pulleys to rotate the pair of chains in the vertical direction, and the bucket also rotates in the rotation direction of the pulleys. With such a configuration, a conveyed product such as powder or granular material can be filled in a bucket that moves upward from the lower part of the casing, and the conveyed product can be conveyed upward by moving the bucket.

FIG. 1 is a block diagram of a control device for a bucket conveyor.
The control device 10 for a bucket conveyor according to the present invention includes a carry amount measuring unit 20 capable of measuring the carry amount on the lifting side of a bucket conveyor (the side that receives a conveyed item, the same applies hereinafter), and a control unit 30 that controls the speed of a drive unit. And a load-out timer 40 to measure the load condition of the bucket conveyor, and when the load of the bucket on the return side (the side for discharging the transported object, the same applies hereinafter) becomes no load or low load, the operating speed of the bucket conveyor Is controlled to slow down the speed.
The carry amount measuring unit 20 is a measuring device capable of constantly measuring the weight of the carried product in the bucket on the lifting side of the bucket conveyor being carried. The carry amount measuring unit 20 is electrically connected to a control unit 30 described later and is configured to be able to transmit a measured value.

The control unit 30 constantly monitors the carry amount on the lifting side of the bucket conveyor on the basis of the measurement value of the carry amount measuring unit 20, and the load on the return side of the bucket is not filled or the load is not loaded. We are aware in advance that the load will be small and the load will be low.
Further, the control unit 30 is electrically connected to a load shortage timer 40 described later. The dead load timer 40 counts an arbitrary set time (for example, 10 seconds or more) when the return-side bucket has no load or a low load (also called a dead load) depending on the measured value, and after the arbitrary set time elapses. The control unit 30 is notified that it is determined that the load state is continuing. By arbitrarily setting the dead time timer 40, it is possible to avoid erroneous determination of dead load based on the variation in the transport amount.
Then, the control unit 30 is electrically connected to the drive unit 50, and controls the drive unit 50 to reduce the operating speed of the bucket conveyor to a low speed when the load-out state continues.
An ammeter capable of detecting the current value of the lifting-side conveyor is installed in place of the carry amount measuring unit 20, and the control unit 30 is configured to detect no load or low load based on the current value of the lifting-side conveyor. You may.

[Action]
The operation of the bucket conveyor control device of the present invention having the above configuration will be described below.
FIG. 2 is a process flow chart of the bucket conveyor control device of the present invention. FIG. 3 is a timing chart of the bucket conveyor control device of the present invention. FIG. 4 is an explanatory diagram of inverter waveforms by the bucket conveyor control device of the present invention. FIG. 5 is an explanatory diagram of the inverter waveform when the load is exhausted.

[Step 1] Measurement of Conveyance Quantity During conveyance of the conveyance article by the bucket conveyor, the weight of the conveyance article filled in the lifting side bucket is constantly measured by the conveyance meter side part 20. At this time, a slight variation in the carry amount is averaged before being used as the carry amount. The control unit 30, which has received the measurement value according to the capacity of the bucket, sets the carry amount in advance (a predetermined carry amount, for example, 15 TON/h), and determines whether the measured value is equal to or more than the predetermined carry amount or less.
[Step 2] Dead load timer arbitrarily set time When the load is less than the predetermined transport amount in step 1, that is, when the rated load of the transport amount shown in FIG. An arbitrary set time (T in FIG. 3, for example, 10 seconds) is measured.

[Step 3] Deceleration of transport speed
When the arbitrary set time elapses, the fact is transmitted to the control unit 30, and the control unit 30 controls the drive unit 50 to reduce the operating speed of the bucket conveyor to a low speed (see the rotation speed in FIG. 3 ). In FIG. 5, deceleration is detected by detecting a decrease in the carry amount. Thereby, the regenerative state can be suppressed.
Then, the carry amount measurement in step 1 is repeated.
[Step 4] Carrying operation at rated speed When the carrying amount is equal to or larger than the predetermined carrying amount in step 1, the carrying operation is performed at the rated speed. FIG. 4 is an inverter waveform in which the load is detected and the rated speed is set after the regenerative amount is suppressed at a low speed in step 3 to suppress the overvoltage trip due to the regenerative energy.
[Step 5] Arbitrary setting time of load dead timer When a load dead occurs during the transport operation at the rated speed in Step 4, the load dead timer 40 is activated to set an arbitrary time of the load dead state (T in FIG. 3, For example, 10 seconds) is measured.
[Step 6] Deceleration of transport speed
When the arbitrary set time has elapsed in step 5, the fact is transmitted to the control unit 30, and the control unit 30 controls the drive unit 50 to reduce the operating speed of the bucket conveyor to a low speed.
Then, the carry amount measurement in step 1 is repeated.
[Step 7] Presence/Absence of Transported Object When the transported object remains, the transport amount measurement in step 1 is repeated. On the other hand, when there are no items to be conveyed, the process ends.

According to the present invention as described above, generation of regenerative energy can be suppressed without consuming the regenerative energy by the converter, the control resistor, or the like.
In addition, it is possible to realize easy and accurate no-load detection by measuring the carry amount. In addition, the facility cost can be controlled. Therefore, more efficient device operation can be continued and productivity is improved.
The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
The present invention is not limited to the combinations shown in the embodiments and can be implemented in various combinations.

INDUSTRIAL APPLICABILITY The bucket conveyor control device of the present invention has industrial applicability particularly in a transport device for industrial product production equipment and building civil engineering equipment.

10 Bucket Conveyor Controller 20 Conveyance Amount Measuring Section 30 Control Section 40 Load Dead Timer 50 Driving Section

Claims (3)

In a bucket conveyor control device that fills a plurality of buckets with a conveyed object and rotates by rotating between upper and lower pulleys,
A control device for a bucket conveyor, comprising: a control unit that performs control to decelerate to a drive unit that drives the bucket based on a no-load or low-load detection value of the lifting-side bucket conveyor that is being conveyed. The bucket conveyor control device according to claim 1,
Providing a conveyance amount measurement unit that measures the conveyance amount of the lifting side bucket during conveyance,
The control device for a bucket conveyor, wherein the control unit performs deceleration control as the detection value of the no load or the low load when the detection value of the conveyance amount measurement unit is less than a predetermined conveyance amount. A control device for a bucket conveyor according to claim 1 or 2, wherein
By providing a dead timer to measure a predetermined time from the detection value of the no load or low load,
The control unit for a bucket conveyor, wherein the control unit performs control to decelerate after the predetermined time has elapsed.

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