JP4267750B2 - Continuous unloader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous unloader that unloads loose objects from bulk carriers, and more particularly to a continuous unloader that detects the distance between the scraper bucket and the bottom of the ship in the vicinity of the bottom of the ship and smoothly shifts to the bottom preparation mode.
[0002]
[Prior art]
In general, a continuous unloader attaches a bucket row to a rigid unloader body and continuously unloads while scraping loose objects in the ship, but when the bottom of the ship and the bucket of the scraper contact, Since an excessive load may be applied and the bucket, the unloader main body, or the ship may be damaged, a device for avoiding an overload caused by contact is provided at the time of bottoming.
In order to operate these devices, means for correctly detecting the distance between the bucket and the bottom of the boat is necessary when the bucket of the scraping unit approaches the bottom of the boat.
[0003]
As a device for this purpose, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-254670 or Japanese Patent Application Laid-Open No. 7-196171, the detection rod provided in the scraping portion is moved forward toward the bottom of the ship, A method for calculating the distance to the bottom of the ship, or as disclosed in Japanese Patent Publication No. 5-11915, ultrasonic waves and electromagnetic waves are transmitted toward the bottom of the ship, and the time from the transmission to the reflection and return is measured. A method for calculating the distance has been proposed.
[0004]
[Problems to be solved by the invention]
However, these methods have problems such as a complicated structure of equipment for detecting the distance between the bucket and the ship bottom and an increase in weight. In addition, since an operation for detecting the distance between the bucket and the ship bottom is required, there is a problem that the efficiency of the original cargo handling work is reduced.
[0005]
The present invention has been made to solve such conventional problems, and its purpose is to accurately detect the distance from the bucket to the bottom of the ship without installing special equipment, and at the same time, smoothly It is to provide a continuous type unloader that shifts to the operation.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a continuous unloader having an L-shaped scraping portion attached to a swing arm rotatable by a hydraulic cylinder at a lower portion of a vertical elevator, and a load cell provided in the scraping portion. Is equipped with a self-weight reduction device that detects the load on the scraping part and controls the hydraulic pressure of the hydraulic cylinder by the load to limit the downward load on the scraping part, and detects the stroke of the swing cylinder rotating hydraulic cylinder. A stroke detection sensor is provided, and the level of the scraping portion at the start of excavation is determined from the difference between the ship bottom detection stroke acquired when the load load of the load cell reaches a preset set load and the initial stroke acquired at the start of excavation. A control device for calculating the distance to the ship bottom is provided.
[0007]
In this way, without providing a special device or sensor for detecting the bottom of the ship, the bottom detection stroke captured when the load load of the load cell reaches a preset set load, and the initial stroke captured at the start of excavation, The distance between the scraping part and the ship bottom can be easily detected from the difference between the two.
[0008]
Further, the present invention sets a range in which the bottom of the swing arm hydraulic cylinder stroke can be adjusted, and the operation mode is switched to the bottom adjustment mode when the bottom detection stroke is within the range in which the bottom can be adjusted. It is characterized by.
[0009]
In this way, the distance between the scraping part and the bottom of the ship can be detected in conjunction with the operation for switching to bottoming operation, so that the distance from the scraping part to the bottom of the ship is within an appropriate range. When the bottom preparation start button is pressed, the operation can be shifted to the bottom preparation work as it is.
[0010]
In addition, the present invention provides that when the bottom adjustment start button is pressed and the stroke of the swing arm turning hydraulic cylinder reaches the maximum stroke and the load load of the load cell does not reach a preset value, It is characterized by outputting a detection signal.
[0011]
In this way, when the bottom push start button is pushed too early and the bucket of the scraping part does not reach the bottom of the ship even if the swing arm is lowered to the maximum, a display of non-detection of the bottom of the ship is given, The operator can easily grasp the situation.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 4, the unloader body 1 that is provided on a travelable machine base 51 that can be swung and raised is provided with a vertical elevator section 4 at its tip. And the unloader scraping part 3 (henceforth the scraping part 3) provided in the vertical elevator part 4 unloads the rose thing in the hold 2a of the main ship 2 continuously.
[0013]
As shown in FIG. 1, the scraping portion 3 mainly includes a bucket 5, a swing arm 6, a swing cylinder 7, a tilt cylinder 8, a chain 13, a scraping frame 31 having spckets 15 and 16 at both front and rear ends, and a parallel. An endless chain 13 composed of links 32 and having buckets 5 attached at regular intervals is stretched over drive sprockets (not shown) provided on the front and rear spkets 15 and 16 and the top of the vertical elevator 4. The swing arm 6 and the scraping frame 31 are supported in an L shape by the swing cylinder 7, the tilt cylinder 8, and the parallel link 32.
The swing cylinder 7 includes a swing cylinder hydraulic circuit 19, and the tilt cylinder 8 includes a tilt cylinder hydraulic circuit 20.
[0014]
The head side hydraulic line 25 and the rod side hydraulic line 26 in the swing cylinder hydraulic circuit 19 are connected to the hydraulic pump 18 via an electromagnetic proportional type directional switching valve 24 (hereinafter referred to as a directional switching valve 24). Further, the direction switching valve 22 is provided in the branch line 33 branched from the head side hydraulic line 25, and the direction is switched to the bypass line 35 connected to the rod side hydraulic line 26 and the distribution line 34 on the outlet side of the hydraulic pump 18. A valve 21 and an electromagnetic proportional pressure control valve 23 are sequentially provided.
[0015]
As shown in FIG. 2 and FIG. 3, the bucket guide roller 12 attached to the bucket 5 is engaged with the guide rail 11 suspended below the scraping frame 31 via the connecting member 36. .
[0016]
On the other hand, the control device 17 includes the load load detected by the load cells 14 a and 14 b provided on the connecting member 36, the stroke of the swing cylinder 7 detected by the stroke detection sensor 37 provided on the swing cylinder 7, and the vertical elevator unit 4. The swing arm inclination angle detected by the provided swing arm inclination angle detection sensor 38 is input.
[0017]
As shown in FIG. 6, in normal cargo handling, the bucket elevator hoisting device (not shown) and the swing cylinder 7 are operated, and the scraper 3 is bitten from the surface of the loose article 9 by a certain depth. The posture is fixed, and the loose object 9 is scraped off by the lateral movement of the unloader. In this state, the direction switching valves 21 and 22 and the direction switching valve 24 of the swing cylinder hydraulic circuit 19 are all in the closed position, and the pressure oil to the swing cylinder 7 is shut off, and the swing cylinder 7 is fixed. Held in position.
[0018]
The following procedure is used to detect the distance between the scraping portion and the ship bottom at the start of excavation during cargo handling.
That is, when the ship bottom 10 approaches, the operator presses a bottom preparation operation start button (not shown) on the operation panel as shown in FIG. 5 (S1). When this button is pressed, the control device 17 stores the stroke of the swing cylinder 7 as an initial value, and at the same time, the swing cylinder hydraulic circuit 19 automatically switches the bucket speed to a low speed appropriate for the bottom. Simultaneously with (S2), the swing arm 6 is lowered at a low speed (S3).
[0019]
Specifically, at the same time when the direction switching valve 24 of the swing cylinder hydraulic circuit 19 is switched in the cylinder extending direction, an electric command for reducing the flow rate is given to the electromagnetic proportional pressure control valve 23.
[0020]
Then, the scraping unit 3 starts to descend slowly toward the ship bottom 10 while scraping the loose material 9. When the timing to press the bottom preparation operation start button is appropriate, the scraping unit 3 descends while scraping the loose article 9 and eventually comes into contact with the ship bottom 10.
[0021]
Then, a reaction force from the ship bottom 10 acts on the bucket 5 of the scraping portion 3, and the load cells 14 a and 14 b are directed upward via the guide roller 12 provided on the bucket 5 and the guide rail 11 meshing with the roller 12. The load of acts. During normal excavation, a downward load is applied to the load cells 14a and 14b due to the weight of the bucket and the weight of the scraped pieces, but when the bucket 5 comes into contact with the ship bottom 10, an upward reaction force is applied thereto. The differential force between the two acts on the load cells 14a and 14b.
[0022]
When the detection values of the load cells 14a and 14b reach the threshold value set in advance (S4), the stroke of the swing cylinder 7 at that time is taken into the control device 17 as the ship bottom detection stroke. Next, the control device 17 calculates the distance (height) from the bucket to the ship bottom at the start of excavation from the difference between the initial stroke and the ship bottom detection stroke.
[0023]
Therefore, if an indicator (not shown) is provided in the cab and this calculated value is displayed, the operator can be informed of the distance from the bucket to the bottom of the ship at the start of excavation.
If the posture of the scraping unit 3 at the time of detecting the ship bottom is appropriate for starting the bottoming operation (see FIG. 7), it is preferable in terms of efficiency to subsequently shift to the bottoming operation.
[0024]
Therefore, a predetermined range is set for the swing cylinder stroke that can start bottoming, and when the bottom detection stroke is within this range, the operation mode is automatically switched to the bottoming mode. (S6), that is, input to the control device 17.
[0025]
When the operation mode is automatically switched to the bottom adjustment mode, the direction switching valve 24 of the hydraulic circuits 19 and 20 is switched to the neutral position, and at the same time, the direction switching valves 21 and 22 are opened. Pressure oil pressure-controlled by the electromagnetic proportional pressure control valve 23 acts on the rod side of the swing cylinder 7 and the tilt cylinder 8. After that, the bucket 5 contacts the ship bottom 10, and the bucket 5 and the ship bottom 10 The bottoming operation is performed in a state where the cargo handling acting in between is controlled.
[0026]
The tilt cylinder 8 is a device for changing the inclination of the scraping unit 3. In the bottom preparation mode, the bucket row is brought into contact with the ship bottom 10 evenly by controlling the pressure of the cylinder 8. Is for. Since the tilt cylinder hydraulic circuit 20 connected to the tilt cylinder 8 has the same configuration and function as the swing cylinder hydraulic circuit 19 connected to the swing arm cylinder 7, detailed description thereof is omitted.
[0027]
Further, when the load detection value does not reach the threshold value when the detection value of the stroke detection sensor 37 of the swing cylinder 7 has reached the maximum stroke value with the bottom start button pressed, the control device 17 does not reach the threshold value. (S 10) It is preferable to program so as to output a ship bottom non-detection signal (S 12) and input it to the control device 17.
[0028]
Although it is assumed that the timing to push the bottom preparation start button is too early and the bucket 5 of the scraping unit 3 does not reach the bottom 10 even if the swing arm is lowered to the maximum (see FIG. 8), the bottom of the ship is not detected. Is displayed, the operator can easily grasp the situation.
[0029]
Further, at this time, a deviation from the bottom ready start range may be read, and a boom hoisting cylinder (not shown) may be operated to compensate for the deviation.
On the other hand, FIG. 9 is obtained by adding a solenoid valve 27 and a throttle valve 28 to the swing cylinder hydraulic circuit 19 to obtain the same functions as those in FIGS.
[0030]
That is, when the ship bottom 10 approaches, the operator presses a bottom preparation operation start button (not shown) provided on the operation panel. When the bottom adjustment operation start button is pressed, the control device 17 automatically switches the bucket speed to a low speed and energizes the float valves 21 and 22 to switch to the self-weight reduction circuit. At the same time, the solenoid valve 27 is energized and a preset electrical command is given to the solenoid proportional valve 23. This electrical command is set so that the pressure of the swing cylinder 7 is slightly smaller than the weight of the scraper 3 coupled to the swing arm 6 is supported.
[0031]
The opening of the throttle valve 28 is set in advance so that the cylinder arm 6 descends slowly. When the bottom preparation start button is pressed, the scraping unit 3 starts to slowly descend toward the ship bottom 10 while scraping loose objects. When the bucket 5 begins to contact the ship bottom 10, a reaction force from the ship bottom 10 acts on the bucket 5 of the scraping portion 3, and the guide roller 12 provided on the bucket 5 and the guide rail 11 that meshes with the roller 12 are provided. Thus, an upward load acts on the load cells 14a and 14b. When the detected values of the load cells 14a and 14b are equal to or less than the threshold value, the solenoid valve 27 is de-energized to switch to the bottom adjustment mode, and the bottom adjustment is performed by the same operation as that shown in FIGS. .
[0032]
【The invention's effect】
As described above, according to the present invention, the bottom detection stroke taken when the load load of the load cell reaches a preset set load without providing special equipment and sensors for detecting the bottom, The distance between the scraping part and the ship bottom can be easily detected from the difference from the initial stroke taken in.
[0033]
In addition, since the distance between the scraping part and the bottom of the ship can be detected in conjunction with the operation for switching to bottoming operation, start the bottoming within the appropriate distance from the scraping part to the bottom of the ship. When the button is pressed, the work can be shifted to the bottom preparation work as it is, and the cargo handling work is not hindered.
[0034]
In addition, when the bottom adjustment start button is pressed, if the stroke of the swing arm turning hydraulic cylinder reaches the maximum stroke and the load load of the load cell does not reach the preset value, a signal indicating that the ship bottom is not detected is sent. If the bottom push start button is pushed too early to output, and the bucket of the scraper does not reach the bottom of the ship even if the swing arm is lowered to the maximum, a display indicating that the bottom of the ship has not been detected is displayed. The operator can easily grasp the situation.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram applied to a continuous unloader of the present invention.
FIG. 2 is a side view of a scraping portion.
3 is a cross-sectional view taken along the line AA in FIG.
FIG. 4 is a side view of a continuous unloader during cargo handling.
FIG. 5 is a control flow diagram.
FIG. 6 is an explanatory view showing a normal excavation position of the scraping portion.
FIG. 7 is an explanatory diagram showing the position of the scraping unit in a normal bottom-reading operation start state.
FIG. 8 is an explanatory diagram showing the position of the scraping portion when the bottom preparation timing is too early.
FIG. 9 is another hydraulic circuit diagram.
[Explanation of symbols]
3 Scraping section 4 Vertical elevator section 6 Swing arm 7 Tilt cylinder 8 Swing cylinders 14a and 14b Load cell 17 Control device 37 Stroke detection sensor

Claims (3)

In a continuous unloader having an L-shaped scraping part attached to a swing arm that can be rotated by a hydraulic cylinder at the lower part of the vertical elevator, the load load of the scraping part is detected by a load cell provided in the scraping part, A self-weight reducing device that controls the hydraulic pressure of the hydraulic cylinder by the load load and restricts the downward load of the scraping part, is provided with a stroke detection sensor that detects the stroke of the hydraulic cylinder for swing arm rotation, and the load of the load cell Equipped with a control device that calculates the distance between the level of the scraping portion at the start of excavation and the distance from the bottom of the ship from the difference between the ship bottom detection stroke taken when the load reaches a preset set load and the initial stroke taken at the start of excavation A continuous unloader characterized by that. A range where the bottom can be adjusted is set for the stroke of the swing arm rotation hydraulic cylinder, and the operation mode is switched to the bottom adjustment mode when the bottom detection stroke is within the range where the bottom can be adjusted. The continuous unloader according to claim 1. When the bottom preparation start button is pressed, if the stroke of the swing arm rotation hydraulic cylinder reaches the maximum stroke and the load load of the load cell does not reach the preset value, a signal indicating that the bottom of the ship is not detected is output. The continuous unloader according to claim 1 or 2, wherein the unloader is configured as described above.

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