JPH09315586A - Quantitative scraper for continuous unloader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform automatic quantitative control of unloading quantity accurately by suspending a scraping part in a freely elevating state by link mechanism, providing an actuator for changing the height of the scraping part and holding this height, and regulating the crossfeed speed of the scraping part according to excavating reaction applied to the actuator. SOLUTION: At the time of holding a scraping part 1a to the requested height (length), the height (length) of the scraping part 1a is detected by an angle sensor 31 provided at a pivotally supported point 30 of a third arm 22, during the operation of a pump 28, and when the scraping part 1a reaches the requested height (length), the pump 28 is stopped, a valve 26 is closed, and the internal pressure of a cylinder chamber 24a is put in a lock stack. In this state, the scraping part 1a is crossfeed. Excavating reaction by a bucket 13 of the scraping part 1a is thereby transmitted to a hydraulic cylinder 24 through link mechanism 16. The excavating reaction of the scraping part 1a can be controlled to be constant by regulating the crossfeed speed of the scraping part 1a according to the pressure applied to the cylinder chamber 24a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous unloader for scraping and unloading bulk materials loaded on a ship or the like, and more particularly to a constant scraping device for a continuous unloader for maintaining a constant unloading capacity. .

[0002]

2. Description of the Related Art A continuous unloader, as shown in FIG.
While having a bucket elevator 1 in which a bucket conveyor 11 is endlessly wound around an elevator section 1b arranged vertically and a scraping section 1a extending horizontally from its lower end, while driving the bucket elevator 1 The scraping unit 1a is laterally fed to scrape the loose object 7.

More specifically, the continuous unloader inserts the bucket elevator 1 into the hold 4 from the hatch opening 3 of the ship 2, then travels the traveling unit 5 and turns the arms 6a and 6b, and rotates the bucket elevator 1 around the vertical axis. The rotation of the scraping unit 1a causes the scraping unit 1a to be fed laterally in the front and back direction of the paper surface, scraping the loose material 7 (coal, iron ore, etc.) in the hold 4 in layers and unloading it through the elevator unit 1b.

Here, considering the post-treatment and the like of the unloaded bulk material 7, it is preferable to make the unloading amount (unloading capacity) per unit time constant. Therefore, conventionally, the pressure value of the drive hydraulic motor of the upper sprocket 8 of the bucket elevator 1 is detected, the lateral feed speed of the scraping section 1a is appropriately changed according to the pressure value, and the unloading amount is controlled quantitatively. .

That is, if the pressure value of the hydraulic motor is larger than a preset set value, it is considered that the scraping amount of the loose material 7 in the scraping unit 1a is excessive, and thus the scraping unit 1a is laterally fed. If the speed is reduced and the pressure value is smaller than the set value, it is considered that the scraping amount is insufficient.
The unloading amount was controlled quantitatively by controlling the transverse feed speed of the.

[0006]

However, in such a quantitative scraping control, the hydraulic motor for driving the sprocket 8 has "excavation force (scraping weight) of the loose material 7 in the scraping portion 1a + elevator portion". Since the lifting force (lifting weight) of the loose object 7 in 1b is added, it is not possible to detect only the scraping weight in the scraping section 1a which is originally necessary.

Therefore, for example, even if the pressure value of the hydraulic motor of the sprocket 8 becomes large, is it due to the fact that the scraping weight of the scraping portion 1a currently being excavated becomes large? It cannot be determined whether the result is that the lifting weight of the elevator portion 1b is increased.

For accurate quantitative control, it is necessary to detect only the current scraping weight in the scraping unit 1a and adjust the lateral feed speed of the scraping unit 1a based on the detected current scraping weight.
Since the conventional quantitative scraping control is based on the "current excavation weight + previous excavation weight", it is difficult to precisely quantitatively control the unloading amount.

[0009]

A quantitative scraping device for a continuous unloader according to the present invention, which was created in consideration of the above circumstances, has a vertically extending elevator part and a scraping part horizontally extended from a lower end of the elevator part. Wrap a bucket conveyor around the take part,
In a continuous unloader for laterally scraping the scraping unit while scraping loose objects while circulating the bucket conveyor, a link that is interposed between the elevator unit and the scraping unit and that suspends the scraping unit so that the scraping unit can be lifted and lowered. Mechanism, an actuator connected to the link mechanism for changing the height of the scraping unit and holding the height, and a lateral feed speed of the scraping unit is adjusted according to an excavation reaction force applied to the actuator. And a control means.

According to the above construction, the scraped weight at the scraping portion is transmitted to the actuator as the excavation reaction force via the link mechanism. Therefore, the control means adjusts the lateral feed speed of the scraping unit in accordance with the excavation reaction force applied to the actuator, so that only the current scraping weight in the scraping unit is used (the elevators that are scraping results before the scraping result). Quantitative scraping control is possible regardless of the lifting weight of the part. As a result,
Accurate automatic quantitative control of unloading amount.

Specifically, the control means lowers the lateral feed speed of the scraping portion when the excavation reaction force of the actuator is larger than a set value and increases the lateral feed speed when the excavation reaction force is smaller than the set value. If

Further, the control means may adjust at least one of the lateral feed speed of the scraping section and the excavation depth based on the excavation reaction force of the actuator.

[0013]

Embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 4, the continuous unloader comprises a traveling section 5 traveling on a wharf 9 along a quay 10, and arms 6a, 6 provided on the traveling section 5 so as to be swingable and liftable.
b, and a bucket elevator 1 rotatably suspended at one end of the arms 6a and 6b. The bucket elevator 1 is configured by winding a bucket conveyor 11 around an elevator section 1b arranged in the vertical direction and a scraping section 1a extending horizontally from the lower end thereof.

In such a continuous unloader, after inserting the bucket elevator 1 into the hold 4 from the hatch opening 3 of the ship 2, the bucket conveyor 11 is circulated and the traveling section 5 is appropriately traveled to raise and lower the arms 6a and 6b. By rotating the bucket elevator 1 around the vertical axis,
The scraping part 1a is fed laterally in the front and back direction of the paper, and the loose material 7 (coal, iron ore, etc.) in the hold 4 is scraped in layers (side cutting), and the upper sprocket 8 and the reverse sprocket 12 reverse each bucket 13. Then, the unloading is performed via a conveyor (not shown) in the arm 6b.

The details of the scraping section 1a are shown in FIG. As shown in the figure, a fixed frame 15 is provided at a lower end portion of an elevator casing 14 that forms an outer shell of the elevator portion 1b and through which the bucket conveyor 11 passes. The scraping unit 1 a is suspended from the fixed frame 15 via a link mechanism 16 so as to be lifted and lowered. Scraping part 1a
Is composed of a tip sprocket 17, a root sprocket 18, and a telescopic frame 19 that supports these to be movable toward and away from each other.

The link mechanism 16 includes a first arm 20 pivotally supported by an outer tubular member 19a of the telescopic frame 19 and a fixed frame 15, a substantially central portion of the first arm 20, and an inner tubular member 19b of the telescopic frame 19. Second arm 21 pivotally supported by
And a third arm 22 pivotally supported by the intermediate portion of the second arm 21 and the fixed frame 15, and suspends the scraping portion 1a so as to be able to move up and down, as shown in FIG. here,
When the scraping unit 1a is lowered, the sprockets 17, 18
Is narrowed (length L), and when the scraping portion 1a is raised, the spacing (length L) between the sprockets 17 and 18 is widened. This is because the length L of the scraping portion 1a is variable and the slack of the chain 23 is prevented.

Between the first arm 20 and the fixed frame 15, there is provided a hydraulic cylinder 24 as an actuator for changing the height of the scraping portion 1a and holding the height. The hydraulic cylinder 24 may be provided between the second arm 21 and the fixed frame 15 and between the third arm 22 and the fixed frame 15. As shown in FIG. 6, when the hydraulic cylinder 24 is extended, the scraping portion 1a becomes longer and rises, and when the hydraulic cylinder 24 is contracted, the scraping portion 1a becomes shorter and descends. The hydraulic cylinder 24
Expansion and contraction is controlled by the hydraulic circuit 25 shown in FIG.

When the hydraulic cylinder 24 is extended, the valve 26 of the hydraulic circuit 25 is closed and the oil in the tank 27 is supplied by the pump 28 into the cylinder chamber 24a of the hydraulic cylinder 24. Then, due to the oil pressure, the hydraulic cylinder 2
The rod portion 24b of No. 4 extends, and the scraping portion 1a is lifted to overcome "its own weight + scraping weight in the bucket 13". When contracting the hydraulic cylinder 24, the pump 28 is stopped and the valve 26 is opened. Then, the scraping unit 1a
Is lowered by "its own weight + scraped weight in the bucket 13" as shown in FIG. 6, and the oil in the cylinder chamber 24a is returned to the tank 27. In the figure, 29 is a check valve.

When the scraping portion 1a is held at a desired height (length), the height (length) of the scraping portion 1a is provided at the pivot point 30 of the third arm 22 while the pump 28 is operating. The angle 28 is detected by the angle sensor 31, and when the desired height (length) is reached, the pump 28 is stopped, the valve 26 is closed, and the pressure in the cylinder chamber 24a may be locked. When the scraping unit 1a is laterally fed in this state, the excavation reaction force of the bucket 13 of the scraping unit 1a is transmitted to the hydraulic cylinder 24 via the link mechanism 16. For example, when the excavation reaction force increases, the pressure in the locked cylinder chamber 24a increases, and when the excavation reaction force decreases, the locked cylinder chamber 2a.
The pressure in 4a decreases.

Therefore, the excavation reaction force of the scraping portion 1a can be controlled to be constant by adjusting the lateral feed speed of the scraping portion 1a according to the pressure applied to the cylinder chamber 24a. This is because the scraping weight of each bucket 13 in the scraping unit 1a, that is, the excavation reaction force, changes when the transverse feed speed of the scraping unit 1a is changed. In this way, the fact that the excavation reaction force can be controlled to be constant means that the scraping weight of the bucket 13 in the scraping unit 1a can be controlled to be constant, and the quantitative scraping control can be performed. Here, the pressure applied to the cylinder chamber 24a is applied only by the current scraping weight of the scraping portion 1a, and has nothing to do with the lifting weight of the elevator portion 1b which is the scraping result before that. Therefore, accurate quantitative scraping control can be performed.

Such quantitative scraping control is performed by the control means 32 shown in FIGS. The control means 32
As shown in FIG. 1, the cylinder chamber 2 is connected to the hydraulic circuit 25.
A pressure sensor 33 for detecting the pressure P applied to the 4a;
An angle sensor 31 is provided at a pivot 30 of the arm 22 and detects the length L of the scraping portion 1a based on the rotation angle thereof. Instead of the angle sensor 31, a sensor that detects the length of expansion and contraction of the hydraulic cylinder 24 may be provided, and the length L of the scraping unit 1a may be detected based on the sensor.

The outputs P and L of these sensors 31 and 33 are
It is input to the map 34 and compared with the constant unloading capacity curve X drawn on the map 34. This curve X is the scraping portion 1a.
Cylinder chamber 24a such that the unloading amount (unloading capacity) per unit time becomes constant when the length L of the
3 is a curve that determines the pressure P of The curve X is determined by experiment or simulation, and the pressure P increases as the length L increases, and the pressure P decreases as the length L decreases. The reason is as follows.

Constant unloading capacity (eg 80% of total capacity)
In order to achieve the above, if the circulating speed of the chain 23 is constant, the scraping amount of each bucket 13 is constant (for example, 80% of the bucket capacity) regardless of the length L of the scraping portion 1a. do it. As shown in FIG. 4, the loose material 7 in each bucket 13 is set at the upper sprocket 8 regardless of the length L.
This is because they are flipped one by one and unloaded. On the other hand, when the length L is long, the number of buckets 13 of the scraping unit 1a is large, and when the length L is short, the number of buckets 13 of the scraping unit 1a is small.

Therefore, in order to keep the scraping amount of each bucket 13 constant regardless of the change in the length L of the scraping portion 1a,
When the length L is long and the number of buckets 13 of the scraping section 1a is large, the pressure P is increased. On the contrary, when the length L is short and the number of buckets 13 of the scraping section 1a is small, the pressure P is large. Should be small. For this reason, the curve X is rising upward. The change in the curve X is non-linear because the scraping unit 1
This is because the scraped weight of the bucket 13 at a is non-linearly converted by the lever ratio of the link mechanism 16 and added to the hydraulic cylinder 24.

Now, when the length L is input to the map 34, the set pressure P at which the unloading ability becomes constant is shown by the curve X.
a is determined. Then, as shown in FIG. 2, the set pressure Pa and the cylinder pressure P obtained from the pressure sensor 33.
When the cylinder pressure P is 90% or less of the set pressure Pa, it is considered that the scraping amount of each bucket 13 in the scraping unit 1a is insufficient, and thus the lateral feed speed of the scraping unit 1a is increased. To be done. Conversely, the cylinder pressure P is less than the set pressure Pa.
If it is 110% or more, the individual buckets 13 in the scraping unit 1a
Since it is considered that the scraping amount is excessive, the lateral feed speed of the scraping portion 1a is decelerated and corrected. If the cylinder pressure P is within ± 10% of the set pressure Pa, the scraping amount of each bucket 13 in the scraping unit 1a is considered to be appropriate, so that the scraping unit 1a
The horizontal feed rate of the current state is maintained. Hunting is prevented because the judgment has a width of ± 10%.

To give a concrete example, as shown in FIG. 3, when the length L of the scraping portion 1a is 5.0 m, the set pressure Pa according to the curve X is 3.1 Kg / cm ^{2 at} which the unloading capacity is constant. Become. Therefore, if the actual cylinder pressure P obtained from the pressure sensor 33 is 2.0 Kg / cm ² as indicated by the triangular mark A in the figure, the scraping amount of each bucket 13 in the scraping portion 1a is insufficient. Since it is considered, the lateral feed speed of the scraping unit 1a is corrected to be increased. The correction amount is proportional to Pa-P. On the contrary, if the actual cylinder pressure P obtained from the pressure sensor 33 is 4.0 Kg / cm ² as indicated by a square mark B in the figure, the scraping amount of each bucket 13 in the scraping portion 1a is excessive. Since it is considered, the lateral feed speed of the scraping unit 1a is similarly decelerated and corrected.

That is, when the length L is 5.0 m, if the cylinder pressure P is 110% or more higher than the set pressure 3.1 Kg / cm ² on the imaginary line 35, the transverse feed speed is reduced and the cylinder pressure P is set to 3.1 Kg. If 90% or less than / cm ^{2, the} transverse feed speed is increased to control the virtual line 35 to approach the curve X. In addition, in FIG. 4, when the length L of the scraping portion 1a is changed during scraping, such as when scraping deep into the hold 4, as shown by a virtual line 36 in FIG. 3, the ability is constant. The set pressure Pa also changes. So in this case
The set pressure Pa is 3.3 Kg / cm ² , and this pressure is compared with the cylinder pressure P.

Such calculation is performed by the calculator 37 which receives the output from the map 34 (see FIG. 1). The lateral feed speed command value after correction of the scraping unit 1a calculated by the calculator 37 is used for the movement of the traveling unit 5 in FIG. 4, the rotation elevation of the arms 6a and 6b, the rotation around the vertical axis of the bucket elevator 1, and the like. It is decomposed into motion speed command values and input to the drive device 38 for each motion. In this way, each drive device 38 is controlled based on the disassembled speed command value, whereby the scraping unit 1a is laterally fed at the corrected speed, and accurate automatic quantitative scraping control is achieved. It is.

The scraping weight of each bucket 13 in the scraping section 1a changes not only with the lateral feed speed but also with the scraping depth. Therefore, the excavation depth of the scraping portion 1a may be adjusted based on the pressure P of the cylinder chamber 24a detected by the pressure sensor 33, and both the excavation depth and the lateral feed speed may be adjusted. You may

[0031]

As described above, according to the quantitative scraping device for the continuous unloader according to the present invention, the scraping section is based on only the excavation reaction force in the scraping section, regardless of the lifting force in the elevator section. Since the lateral feed speed of is adjusted, accurate quantitative scraping control can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a quantitative scraping device of a continuous unloader showing an embodiment of the present invention.

FIG. 2 is a diagram showing a flow of control means.

FIG. 3 is a diagram showing a map of control means.

FIG. 4 is an overall view of a continuous unloader.

FIG. 5 is an enlarged view of a scraping unit.

FIG. 6 is a diagram showing changes in length and height of a scraping unit.

[Explanation of symbols]

 1a Scraping part 1b Elevator part 7 Loose object 11 Bucket conveyor 16 Link mechanism 24 Hydraulic cylinder as actuator 32 Control means

Claims (3)

[Claims] 1. A bucket conveyor is wound around a vertically arranged elevator part and a scraping part extending horizontally from a lower end thereof, and the scraping part is laterally fed while circulating the bucket conveyor to separate the parts. In a continuous unloader for scraping objects, a link mechanism interposed between the elevator section and the scraping section for suspending the scraping section so that the scraping section can be lifted and lowered, and a height of the scraping section connected to the link mechanism Quantitative scraping of a continuous unloader, comprising: an actuator that changes and maintains its height; and a control unit that adjusts the lateral feed speed of the scraping unit according to the excavation reaction force applied to the actuator. apparatus. 2. The control means lowers the lateral feed speed of the scraping portion when the excavation reaction force applied to the actuator is larger than a set value, and increases the lateral feed speed when the excavation reaction force is smaller than the set value. The quantitative scraping device for a continuous unloader according to claim 1. 3. The continuous unloader according to claim 1, wherein the control means adjusts at least one of the lateral feed speed and the excavation depth of the scraping portion based on the excavation reaction force of the actuator. Quantitative scraping device.