JPH0930654A - Continuous unloader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent objects transported from falling off in the event of failure occurrence by stopping the driving means upon judgement of failure in the circulatively running condition on the basis of signals given by a sensor, and actuating a braking means. SOLUTION: When an unloader 1 is in operation, a controller 25 controls the rate of flow of the pressure oil fed by a hydraulic pump 23 so that an upper hydraulic motor 8a (7a) is operated at a target speed. To the controller 25 a speed sensor 26 feeds an output signal which indicates the actual operating speed of the upper motor 8a. When the ratio of the actual speed to the target speed value is below the reference value, the controller 25 pases a judgement that slip is generated in either lower hydraulic motor 7b, 8b resulting from setting-off of a chain 6. etc., and that a failure is generated in the circulative running condition of the bucket conveyor 3. Accordingly an electric motor 22 is stopped and a braking mechanism 18 is actuated forcedly. The hydraulic motors 7a... stop, and the bucket conveyor 3 is prevented from inversion caused by its own weight or the load of the objects transported.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to a continuous unloader adopting a so-called tandem drive system for driving a bucket conveyor at two points.

[0002]

2. Description of the Related Art The applicant of the present invention has already proposed a continuous unloader of this type (Japanese Patent Application No. 3-84120). According to this, a bucket conveyor has two parts, an upper part of an elevator part and a scraping part. Since the drive is circulated in one drive position, the tension applied to the chain of the bucket conveyor can be reduced, and the size of the chain and the weight of the device can be reduced.

[0003]

In this tandem drive type continuous unloader, the chain of the bucket conveyor is driven through the sprockets by synchronously rotating the hydraulic motors provided at the respective drive positions. .

However, if an abnormality such as the chain coming off the sprocket or the sprocket being damaged occurs during the cargo handling work, the drive may become impossible and the load rising up the elevator may drop. .

That is, the hydraulic motors at the respective driving positions are connected by a hydraulic circuit of one system, and when the above-mentioned abnormality occurs even at one place, all the hydraulic pressures are transferred to the light-load hydraulic motors having the abnormality. As a result, the hydraulic motor and sprockets spin idle, the bucket conveyor is not driven, the bucket conveyor reverses due to the load in the bucket, its own weight, etc., and a relatively heavy load (about 30 tons) falls at a stretch. As a result, it also poses a danger to workers below.

Therefore, the present invention was devised to solve the above problems, and an object of the present invention is to provide a continuous unloader capable of preventing a load from dropping when an abnormality occurs.

[0007]

In order to achieve the above object, the present invention is a continuous unloader having a bucket conveyor that is cyclically driven in at least two drive positions, the bucket conveyor being provided in each of the drive positions. Driving means, a braking means provided to brake the bucket conveyor, a sensor for detecting a circulating movement state of the bucket conveyor by the driving means, and a movement state of the movement state based on a signal from the sensor. And a controller that determines an abnormality and stops the drive means and actuates the brake means.

According to the present invention, when an abnormality occurs, the drive means is stopped, and at the same time, the bucket conveyor is braked by the brake means, so that the reverse rotation of the bucket conveyor and the dropping of the load are prevented.

[0009]

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

FIG. 1 shows a continuous unloader according to the present invention. The continuous unloader 1 is attached to the tip of a boom (not shown) provided on a wharf (not shown),
The scraping unit 2 located at the lower end is thrust into the hold (not shown) so that the bucket 4 of the bucket conveyor 3 scrapes off the load in the hold, especially the iron ore or coal as loose material. Has become. The load scraped into the bucket 4 rises in the elevator section 5 by the circulating movement of the bucket conveyor 3 in the direction of the arrow, and is conveyed to the ground via a table feeder, a conveyor, and the like (not shown).

The bucket conveyor 3 comprises a pair of endless chains 6 separated from each other, and a plurality of buckets 4 (only one is shown) connecting the chains 6 at equal intervals in the chain longitudinal direction. The scraping unit 2 is formed by horizontally extending at the lower end of the elevator unit 5 extending vertically. The upper end position and the lower end position of the elevator unit 5 are respectively an upper drive position a and a lower drive position b for driving the bucket conveyor 3, and the bucket conveyor 3 is substantially driven at these drive positions a and b, respectively. Hydraulic motors (driving means) 7a, 8a, 7b,
8b are provided.

At the upper drive position a, the drum member 9 is integrally and coaxially coupled to the drive shafts of the upper hydraulic motors 7a and 8a which are arranged to face each other, whereby the respective hydraulic motors 7a and 8a are uniaxially connected. It is operated at a constant speed.
At both ends of the drum member 9, upper sprockets 10a, 11 are provided.
a is integrally provided and these sprockets 10a, 1
The upper end of each chain 6 is wound around 1a, and the bucket conveyor 3 is driven by the upper hydraulic motors 7a and 8a.

Even at the lower drive position b, the lower hydraulic motors 7b and 8b are arranged so as to face each other, and the lower sprockets 10b and 11 are attached to the drive shafts of these hydraulic motors 7b and 8b.
b are attached respectively. These lower sprockets 10b and 11b are the upper sprockets 10a and 11b.
It is located directly below the extension direction of a of the elevator. Each chain 6 is wound around the lower sprockets 10b and 11b,
The bucket conveyor 3 is also driven by the lower hydraulic motors 7b and 8b. In particular, here, each hydraulic motor 7b, 8
Since the drive shaft of b is not connected, the hydraulic motors 7b and 8b are operated independently and at a constant speed in synchronization with the upper hydraulic motors 7a and 8a.

In addition to the sprockets 10a, ..., Each chain 6 of the bucket conveyor 3 has an upper idle sprocket 12 provided at the upper end side of the elevator section 5, and an intermediate section provided at the boundary between the elevator section 5 and the scraping section 2. The idle sprocket 13 and the lower idle sprocket 14 provided at the tip of the scraping unit 2 are also wound and guided. These idle sprockets 12 are driven to rotate as the chain 6 circulates. In particular, the lower idle sprocket 14 and the lower sprocket 10b,
A lower side portion 15 of the bucket conveyor 3 connecting with 11b forms a substantial scraping portion of a load and extends in a direction perpendicular to a rising portion 16 of the bucket conveyor 3 located in the elevator portion 5. Thus bucket conveyor 3
Circulates between the sprockets described above in the direction of the arrow.

Although not shown in the drawings, the continuous unloader 1 has a telescopic jack for moving the lower idle sprocket 14 toward and away from the lower sprockets 10b, 11b, and an intermediate idle for absorbing the chain 6 length. A jack for moving the sprocket 13 and a tilting jack for tilting the lower side part 15 with respect to the rising part 16 are provided, and the scraping part 2 or the lower side part 15 is provided.
The posture (position, size, etc.) can be appropriately changed according to the actual scraping situation.

In addition, at the upper drive position a, the unloader 1 is attached to the drive shaft 17a of one upper hydraulic motor 7a.
A brake mechanism (brake means) 18 is provided for braking or stopping the bucket conveyor 3 when the operation is stopped. The brake mechanism 18 is a disc brake mechanism in this embodiment, and specifically, is mainly composed of a disc 19 attached to the drive shaft 17a and a caliper mechanism 20 fixed to a frame (not shown). Caliper mechanism 2
0 has a built-in brake pad, which is mechanically actuated at the same time as the unloader 1 is stopped to automatically grip the disk 19, thereby braking the drum member 9 and stopping the bucket conveyor 3 Are regulated to move. Therefore, when the unloader 1 is stopped, the bucket conveyor 3 is held at the current position with the bucket 4 loaded.

The unloader 1 is provided with a hydraulic pressure supply section 21 for supplying hydraulic pressure to the hydraulic motors 7a. The hydraulic pressure supply unit 21 is mainly composed of an electric motor 22 and a hydraulic pump 23 directly connected to the electric motor 22. The hydraulic pump 23 employs a swash plate type, which has a mechanism in which a plate is inclinedly attached to the shaft of the electric motor 22 and the piston is reciprocated by the rotation of the plate to pump the hydraulic oil. The hydraulic pump 23 can adjust the pressure-feed oil flow rate by controlling the inclination angle of the plate described later. The hydraulic oil from the hydraulic pump 23 or the hydraulic oil whose pressure has been increased is supplied to each hydraulic motor 7a ... By one hydraulic path 24 (shown by a chain line) and used to drive the bucket conveyor 3. The hydraulic oil that has become a low pressure after driving is returned to the tank that stores the hydraulic oil through a low-pressure hydraulic path (not shown). Further, the unloader 1 is subjected to speed control, attitude control, and the like during operation. At the same time, there is provided a controller 25 with a built-in computer that also executes an emergency stop of the unloader 1 described later. The controller 25 is electrically connected to the electric motor 22, the hydraulic pump 23, the caliper mechanism 20 of the brake mechanism 18, and the speed sensor (sensor) 26 (wiring is indicated by a chain double-dashed line). Here, the speed sensor 26 is specifically a rotary encoder, which is connected to one of the upper hydraulic motors 8a to detect its operation or rotation speed.

During operation of the unloader 1, the controller 25
While operating the electric motor 22 at a constant speed, the hydraulic pump 23 performs the above-described tilt angle control to adjust the pressure-feed oil flow rate and operate each hydraulic motor 7a ... At a predetermined speed corresponding to the load carrying speed. . At the same time, the above-mentioned jacks are operated by an operation from the outside to execute the posture control of the unloader 1 to the scraping unit 2.

By the way, in the above structure, the upper sprockets 10a and 11a are subjected to the weight of the bucket conveyor 3 and the load of the load, and the upper sprockets 10a and 1a are
It is unlikely that the chain 6 will disengage from the 1a, but if the idle sprockets 13 and 14 do not move in synchronism with each other during the attitude control described above, the chain 6 disengages from the lower sprockets 10b and 11b, and the driving force acts at all. There is a risk that it will not be done. For example, when the chain 6 is disengaged from one of the lower sprockets 10b, the lower hydraulic motor 7b that drives the chain 6 has no load, and most of the hydraulic oil concentrates on the lower hydraulic motor 7b, which significantly speeds up the hydraulic motor 7b. Since the other hydraulic motors 7a, 8a, 8b are not supplied with hydraulic pressure, they are equal to idle or stopped states. In this case, the hydraulic motors 7a, 8a, 8b can be reversely driven by the weight of the bucket conveyor 3 or the like, so that the bucket conveyor 3 also reverses its original circulation direction, resulting in the drop of the load. I will invite you. Further, since the hydraulic motor 7b is excessively speeded up, heat is generated from the hydraulic motor 7b itself or the hydraulic pump 23, which is dangerous. This is also the case when the sprocket 10b is damaged and the driving force cannot be transmitted.

Therefore, in this embodiment, an emergency stop of the unloader 1 is carried out when the circulating movement state of the bucket conveyor 3 is abnormal.

FIG. 2 shows a flow chart of control performed by the controller 25. During operation of the unloader 1, the controller 25 determines the command speed V ₀ in step S1.
The hydraulic oil flow rate of the hydraulic pump 23 is controlled so that the upper hydraulic motor 8a (7a) is operated. Then step S2
In, the controller 25 inputs an output signal indicating the actual operating speed Vx of the upper hydraulic motor 8 a from the speed sensor 26. Then, in step S3, the ratio Vx / V ₀ between V ₀ and Vx is compared with the comparison value V ₁ = 0.9,
When it is V ₁ or more, the actual operating speed Vx is sufficient, and the circulating state of the bucket conveyor 3 is normal.
It is determined that the chain 6 has not come off, and the process returns to step S2. On the other hand, when Vx / V ₀ is less than V ₁ , it means that the actual operating speed Vx is smaller than the speed at the normal time. , 8b is idle,
When it is judged that an abnormality has occurred in the circulating movement state of the bucket conveyor 3, the process proceeds to the next steps S4 and S5,
At the same time as stopping the electric motor 22 in S4, step S4
The brake mechanism 18 is forcibly operated.

When this happens, the hydraulic pump 23 also stops, the hydraulic pressure supply to the hydraulic motors 7a ... Is stopped, and the hydraulic motors 7a. At the same time, the movement of the bucket conveyor 3 is completely restricted by the brake mechanism 18, and the bucket conveyor 3 is prevented from being reversed due to its own weight or the load of the load. The reliability and reliability are greatly improved.

Particularly in this embodiment, since the speed sensor 26 is connected to the upper hydraulic motor 8a at the upper drive position a,
For example, as compared with the case where the lower hydraulic motors 7b and 8b are connected, it is possible to prevent pollution due to coal or the like. Also,
The value of the comparison value V ₁ is set to 10% instead of 1.
Since it is set to 0.9, it is possible to allow the actual operating speed Vx to fluctuate and prevent an unexpected emergency stop.

It should be noted that the present invention is not limited to the above-mentioned form, and it is possible to set each drive position to another place, for example. Further, in the present embodiment, a speed sensor is used as a sensor to detect the circulating movement state of the bucket conveyor by replacing it with the operating speed of the hydraulic motor, but this can also be changed to another one. A torque sensor that detects the output torque of the motor or a flow meter that detects the flow rate of oil supplied to the hydraulic motor may be used.

[0025]

The present invention exhibits the following excellent effects.

(1) It is possible to prevent a load from dropping when an abnormality occurs.

(2) The safety and reliability can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing one form of a continuous unloader according to the present invention.

FIG. 2 is a flowchart of control performed by a controller.

[Explanation of symbols]

 1 Continuous Unloader 3 Bucket Conveyor 7a, 8a Upper Hydraulic Motor (Drive Means) 7b, 8b Lower Hydraulic Motor (Drive Means) 18 Brake Mechanism (Brake Means) 25 Controller 26 Speed Sensor (Sensor) a Upper Drive Position (Drive Position) b Lower drive position (drive position)

Claims (1)

[Claims] 1. A continuous unloader having a bucket conveyor cyclically driven in at least two drive positions, the drive means being provided in each of the drive positions to drive the bucket conveyor, and to brake the bucket conveyor. The braking means provided, a sensor for detecting the circulating movement state of the bucket conveyor by the driving means, the abnormality of the movement state is judged based on a signal from the sensor, the driving means is stopped, and A continuous unloader, comprising: a controller that operates a braking means.