JPH06115872A - Automatic handling method for scrap by grab bucket - Google Patents

Abstract

PURPOSE:To perform automatic handling by stopping lowering of a grab bucket when non-load is detected as a result of the grab bucket landing on a ground, and grasping scraps through closing operation of the bucket, and thereafter executing hoisting of a crane after given processing is carried out. CONSTITUTION:After, when a command is outputted from a control device, a grab crane is moved to a specified address, high speed lowering is first effected, and slow speed lowering is effected in a given position and the claws 4 of a bucket 1 are opened. When the lowering is effected, the bucket 1 lands on a ground and when a non-load state is detected by a crane scale, the claws 4 are closed. In this case, the bucket 1 is caused to rise by means of a size difference H and a rope is brought into a slacked state. By detection of the slacking of the rope, slow speed hoisting of the crane is executed to eliminate the slack of the rope, and the fall of a bucket body 3 is prevented from occurring. When closing operation of the claws 4 is stopped, simultaneously with execution of slow speed hoisting, release of an overload is repeatedly effected and thereafter, the bucket is brought into a fastening state to perform winding at a given speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scrap handling method, and more particularly to an automatic scrap handling method using a grab bucket.

[0002]

Scrap conventionally processed in a scrap yard of an electric furnace factory has a bulk specific gravity of 0.6 to
There are various scraps with a wide range of 3.0 and the shape is indeterminate. As a method of handling these scraps, a lifting magnet crane (hereinafter, simply referred to as a riff mag crane) that is easy to handle scraps is generally used. However, in the case of light weight scrap having a bulk specific gravity of 1.0 or less, the handling weight per operation is small, and therefore a grab bucket crane (hereinafter simply referred to as a grab crane) may be used in some cases. . However, it is extremely difficult to handle all the scraps efficiently and in a short time with only one of the riff mag crane and the grab crane.

Therefore, in order to realize efficient scrap handling, the applicant of the present invention must use the bulk specific gravity of the scrap in an efficient combination depending on the characteristics of the riff mag crane or grab crane. Thinking about it, I filed an application for automation in the scrapyard first. This application aims to automate the loading and receiving of scrap in the scrap yard by handling heavy scrap with a riff mag crane and handling light scrap with a grab crane, and performing efficient scrap handling by combining these. It is what

However, the handling of scrap of which shape is uncertain by the bucket of the grab crane largely depends on the skill of the crane operator. That is, in general, when handling scraps with a grab bucket, scraps are first scraped by bucket claws, the claws are closed while compressing and deforming the collected scraps, and finally the scraps are picked up with the claws closed. . In this case, if any one of the claws of the grab bucket hits a scrap that is large in shape or cannot be compressed and deformed, the unloader of the claw actuating cylinder acts to stop the claw closing operation on the way. Therefore, the crane operator can remove the claws from the scraps while avoiding the unloader or by tilting the grab body forward, backward, leftward, or rightward, and visually confirm that the grabs have completely grasped the scraps while avoiding them. The current situation is to wind up and handle scrap. All of these operations are left to the skill of the crane operator who manually operates the grab bucket.

Incidentally, as a conventional technique of this kind, the actual development 6
Although there are the inventions described in JP-A 2-65488 or JP-A-62-79788, the inventions described in these publications relate to a grab bucket equipped with a lifting magnet, and do not relate to automatic handling of the grab bucket itself in the present invention. Absent.

[0006]

By the way, in the electric furnace operation in recent years, there is a tendency that the scrap is simply melted in the electric furnace, and then the components are adjusted by refining outside the furnace.
Therefore, the operation time (Tap to Tap) in the electric furnace is significantly shortened, and as a result, it is necessary to melt and process a large amount of scrap in a short time.

Further, the bulk specific gravity for melting scrap most efficiently in an electric furnace is said to be 0.74. In order to achieve that bulk specific gravity, scraps of a plurality of brands are combined, and as a general rule, it is difficult to melt. It is important that the scraps are layered in order and charged into the electric furnace. In order to satisfy these conditions and to further obtain scrap preheat by electric furnace exhaust gas as long as possible, in order to load scrap into the electric furnace charging basket in a short time and efficiently, the loading must be done in advance. There is also a need to keep going.

In other words, in the recent large-capacity scrap processing, the skillful handling operation of the grab bucket by the crane operator as described above makes it possible to load various scraps in a short time and to add dust and noise. In order to perform complicated work in the building, improvement of the working environment is required, and this is the reason why automation of this kind of scrap yard is desired.

Therefore, in order to realize the automation of the scrap yard in response to the demand for a large amount of scrap processing and the improvement of working environment in the recent electric furnace operation, a rapid and efficient automatic scrap handling method using the optimum equipment is required. Is required.

However, as described above, since the handling of scrap is left to manual operation depending on the skill of the crane operator, in order to realize the automation of the scrap yard, the operation more than the manual operation of the crane operator is automatically operated. A method for doing so is required.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for automatically handling a large amount of light-weight scrap, which occupies the majority of electric furnace charging scrap, with a grab crane.

[0012]

In order to achieve the above object, in the automatic scrap handling method using a grab bucket according to the present invention, the grab bucket is unwound at a predetermined address and the unwinding is stopped when no load is detected. Then, while closing the grab bucket, if the closing operation raises the grab bucket and loosens the crane rope, the crane rope is wound up by a predetermined amount, and the grab bucket detects a closing stop due to overload. Alternatively, after the closing operation is continued for a predetermined time, the overload of the grab bucket is released, and the crane is hoisted at a predetermined low speed while tightening the grab bucket.

[0013]

According to the above method, the grab bucket is unwound at a predetermined address, and when the grab bucket lands and no load is detected, the unwinding is stopped. When the grab bucket is closed by the closing operation of the grab bucket and the glove bucket is lifted by the closing operation to loosen the crane rope, the crane rope is wound up by a predetermined amount.

Thereafter, when the grab bucket detects the closing stop due to overload or the closing operation is continued for a predetermined time, the crane is hoisted at a predetermined speed, and at this time, the overload of the grab bucket is released and the grab bucket is retightened. While winding up at a predetermined low speed.

By properly operating the grab and the crane at any place in this way, it is possible to automatically handle the irregular scrap.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view showing a grab bucket, and FIG.
3 is a flowchart of a handling method according to the present invention.

First, the grab bucket 1 used in the present invention.
1 is suspended by a crane hook 2a provided at the tip of a crane wire 2, and this crane hook 2a suspends a grab bucket body 3 having a grab bucket suspension fitting 3a. . The glove bucket body 3 is provided with a plurality of claws 4 around its lower portion, and the claws 4 can be opened and closed by being pivotally supported by the support portion 5 of the glove bucket body 3. A support portion 6 is also provided around the upper portion of the main body 3 where the claw 4 is located, and a drive device such as a hydraulic cylinder 7 is mounted between the support portion 6 and the base portion of the claw 4. There is. Then, by expanding and contracting the hydraulic cylinder 7, the claw 4 opens and closes as shown by the chain double-dashed line. In addition,
H is a vertical dimensional difference that occurs when the claw 4 is opened and closed.

Further, in automating the handling of scrap in the scrap yard, the entire yard is virtually subdivided in advance, and each subdivided part is given an address, thereby making the entire yard an address. It is stored in a control device (not shown). Therefore, the type of scrap by brand and the handling position in the pit are all controlled by the control device, and the grab bucket is run and traverse in a plane by controlling and controlling the address in the yard, and the average fixed amount is always maintained. I am able to handle the scraps of.

An automatic handling method using the glove bucket 1 configured as described above will be described with reference to the flowcharts of the present invention shown in FIGS. 1 and 2.

First, when a command is issued from the control device, an automatic loading grab crane that runs and traverses over a yard runs at a high speed and traverses to a designated address, automatically decelerates before the designated address, and has a certain stopping accuracy. Stop within (a).

Next, in the process (b) of lowering the grab bucket, the glove bucket is fast-wound to a predetermined position, decelerated at the predetermined position, and finely-wound. In this case, in order to efficiently perform the lowering process at the predetermined position for deceleration, the previous landing level is stored, and the level is used as a reference for deceleration from a certain height before and at the same time the claw of the grab bucket is moved. Make it open (c). The landing detection of the grab bucket is performed by the no-load detection of the crane scale of the crane (d). In this way, the grab bucket is softly landed on the scrap yard surface and the lowering is stopped (e).

After landing, the claws 4 of the grab bucket 1 are closed (f). At this time, as the claws 4 are closed, the glove bucket 1 rises up due to the dimensional difference H shown in FIG. 3, the glove bucket suspension metal fitting 3a may sometimes come off the crane hook 2a. Therefore, a rope slack detection device is installed to detect rope slack (g) .When rope slack is detected, the crane is hoisted at a slow speed and stopped (h), and the hook rope is controlled so that it does not slack all the time. There is.

The means for detecting the looseness of the rope may be an existing method. For example, the crane is hoisted at a very low speed by a detection signal from a limit switch abutting on the rope, a detection signal of wire slack by a photoelectric tube, or the like.
A crane winch with a built-in auto-tension mechanism may be used to prevent the rope from loosening, and the rope may be moved by the dimensional difference H that rises when the grab bucket 1 moves from the open state to the closed state. Any structure may be used as long as it loosens up.

On the other hand, the claws of the grab bucket differ depending on the brand of scrap, but in general, in the first claw closing operation process, one closing operation rarely completely closes, and the claws stop halfway. This is because the claw hits scrap that cannot be handled or deformed, which detected overload (i), and the unloader of the hydraulic unit for the claw actuating hydraulic cylinder actuated and stopped.
(j).

Therefore, when the claw closing operation stops due to this overload detection, the scrap that is an obstacle to this closing operation is removed or deformed from the claw, and at the same time as the slow speed winding (k), the overload Repeat the release to keep the hydraulic cylinder pressurized and re-tighten the grab bucket (l) so that the pawl is completely closed. The hoisting speed of this crane is 5 to 10
The optimum speed is about m / min (2 notches), which is the optimum speed for digging a grab bucket that holds ground scrap.

By the way, as described above, when handling scraps, the scraps scraped by the bucket claws are compressed and deformed to close the claws, and the scraps are finally picked up with the claws closed. Need time. In other words, the time T from the operation (f) of closing the claw of the grab bucket after landing to the stop (j) of the hydraulic unit for the hydraulic cylinder 7 for claw operation to stop (j) is a predetermined time. It is necessary to maintain T, and the predetermined time T is about 15 seconds to 20 for a general heavy, according to an experiment by the applicant.
Seconds, shredder or Dalai powder is about 10 seconds ~
15 seconds is optimal.

Therefore, the overload detection (i) in the above flowchart is a case where the overload is detected while the grab bucket closing operation is continued for the predetermined time T, and the overload is detected within the predetermined time T. If not, the glove bucket closing operation is stopped for a predetermined time T and stopped, and the next slow-speed hoisting operation is performed (k).

After winding a certain amount (for example, 1 m)
Stop (m), detect the grab bucket closing signal at this position (n), retighten the grab bucket if the grab bucket is not closed (o), and detect the grab bucket closing signal and then lift the crane. Weigh the amount of scrap grasped by the grab bucket on the scale (p), if it is above the specified value, rapidly wind it up (q), then traverse to the specified weighing hopper and run the scrap into the weighing hopper (r). . And
Run or traverse to the next designated address (a).

If the measured value is not more than the specified value,
As the handling was unsuccessful, the claws were opened (s), the glove bucket was wound up to the specified size (t), and then traversed to the next address (u),
The glove bucket handling process is performed again from the lowering (b) of the glove bucket described above.

As described above, according to the present invention, in the scrap handling process by the grab bucket,
By keeping one claw closing operation for a predetermined time, scrape as much scrap as possible and compressing and deforming to close the claws, and then slowly winding up to release the overload and retighten the claws to the fully closed state. By doing so, it is possible to almost certainly grasp the scrap of the specified value or more, and therefore it is possible to automatically handle the scrap, which can reduce the grasp failure as much as possible.

Further, according to the automatic handling method by the grab bucket of the present invention, it is possible to handle medium and light weight scraps, so that it is necessary to efficiently handle a large amount of scraps in a short time as in recent years. In a certain scrap yard, unlike a visual operation by a crane operator, this is an effective handling method for realizing automation of the scrap yard in arbitrary scrap handling.

Further, in the unwinding process, deceleration control is always performed based on the previous landing level, so that the shortest efficient unwinding operation can be performed and the grab bucket can always be softly landed on the scrap surface. Noise during handling can be reduced.

The specified value for weighing the scrap weight by the crane scale in the above flow chart must be determined by the time schedule of the entire scrap yard. For example, 50 to 80% of the grab bucket capacity should be set as the specified value. You can do this.

[0034]

According to the present invention, in the scrap handling process, a large number of scraps are scraped and grasped by continuing the closing operation of the claws for a predetermined time, and then the claws are fully tightened while being slowly wound up to completely close the claws. By taking it in, you can reduce the number of missed grasps as much as possible.

Therefore, according to this handling method,
Automatic handling of medium and lightweight scrap is possible,
This is a scrap handling method that makes it possible to realize automation of a scrap yard for handling a large amount of scrap in a recent scrap yard in a short time and efficiently.

In the lowering process of the grab bucket, the deceleration control is always performed with reference to the previous landing level, so that the shortest efficient lowering process can be performed, and the noise due to scrap drop can be reduced and the grab bucket can be lowered. Since the operation is performed at a very low speed, there is an effect that there is little noise when handling scrap.

[Brief description of drawings]

FIG. 1 is a front view showing a grab bucket for carrying out a handling method of the present invention.

FIG. 2 is a flowchart of an automatic handling method according to the present invention.

[Explanation of symbols]

 1 ... Grab bucket 2 ... Crane wire 3 ... Grab bucket main body 4 ... Claws 5, 6 ... Support part 7 ... Hydraulic cylinder

Claims (1)

[Claims] 1. When the grab bucket is unwound at a predetermined address and no load is detected, the unwind is stopped, the glove bucket is closed, and the grab bucket is lifted by the closing operation and loosened on the crane rope. When the above occurs, the crane rope is hoisted by a predetermined amount, the grab bucket detects a closing stop due to overload, or if the closing operation is continued for a predetermined time, the grab bucket overload is released and the grab bucket is retightened. An automatic scrap handling method using a grab bucket, which is characterized by hoisting a crane at a predetermined low speed.