JP3853493B2 - Continuous unloader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous unloader that unloads loose objects such as ore and coal, and more particularly, to a continuous unloader that can flexibly follow a scraping portion against the shaking of a ship.
[0002]
[Prior art]
Conventionally, a swivel mast that is suspended from the top support frame of the boom and is rotatable about an axis, a lift frame that is supported by the lower end of the swivel mast so as to be movable up and down, and is pivotally supported by the lift frame horizontally. A lever member having a slidable tip, a tilting cylinder for tilting the lever member, and an endless shape for transporting a loose article suspended from the tip of the lever member along the longitudinal direction of the swivel mast A bucket and an expansion / contraction cylinder for urging and expanding / contracting the tip of the lever member in order to apply a predetermined tension to the bucket, and further storing a constant fluid pressure in the expansion / contraction cylinder Connecting the accumulator that absorbs the loosening of the endless bucket that occurs when the lifting frame is lifted by the boat being pushed up. Unloader is known.
[0003]
[Problems to be solved by the invention]
However, since the above unloader only adjusts the set pressure of the accumulator, the reaction force received by the bucket changes due to the fluctuation of the resistance of the expansion cylinder and the loss of the mechanical system.
Since the contact pressure of the bucket is directly related to the tension pressure, each cannot be arbitrarily set. That is, the tension pressure needs to be set to an optimum value for smooth operation of the bucket row, but the ground contact pressure of the bucket is uniquely determined. Even if only the ground pressure is changed to the optimum value, it cannot be changed.
[0004]
Furthermore, the unloader does not give any consideration to the inclination of the hull.
The present invention has been made in view of the conventional problems, and the object of the present invention is to scrape up and down and tilt the hull by constantly measuring the load acting on the unloader. An object of the present invention is to provide a continuous unloader that can flexibly follow a bucket.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a continuous unloader according to the present invention has a scraping frame attached to a swing arm rotated by a swing cylinder and a tilt cylinder for tilting the scraping frame to the swing arm. Furthermore, in a continuous unloader in which a plurality of buckets are attached to an endless chain that circulates around the scraping frame and the swing arm, a pair of front and rear load cells that detect a load acting on the bucket on the scraping frame And a control system for controlling the swing cylinder thrust and the front load cell so that the deviation between the sum of the loads detected by these load cells and the preset set load for the entire frame becomes zero. Load and preset load related to the frame front It is characterized in that it comprises a control device the deviation has a control system for controlling the tilt cylinder thrust to be zero.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 7, a pivotable boom 52 is provided on the upper portion of the traveling body 1 provided on the wharf 51 for unloading. A chain bucket is provided at the front end side of the boom 52, and the excavation part 53 scrapes off the bulk material 5 such as ore loaded on the ship 4, and the bulk material 5 scraped off at the excavation part 53 moves upward. And a vertical elevator portion 2 that transports and discharges.
[0007]
As shown in FIG. 1, in the elevator column 11, one end of the swing arm 10 and one end of the tension rod 12 are respectively provided on the component surface 41 adjacent to the surface having the opening (not shown). The hinge pin 42 is pivotally supported by the hinge pin 42.
Further, the tie rod 13 is pivotally supported by a hinge pin 43 so as to connect the other end of the swing arm 10 and the tension rod 12, and is constituted by the swing arm 10, the tension rod 12, the tie rod 13, and the component surface 41. A parallel link mechanism having the surface 41 as a fixed portion is formed.
[0008]
A swing cylinder 14 serving as an actuator is provided near the attachment portion of the tension rod 12, and the tip of the cylinder rod 44 of the swing cylinder 14 is linked to the middle part of the swing arm 10. A horizontal frame 9 serving as a scraping frame is rotatably coupled to a link coupling portion between the tie rod 13 and the swing arm 10. Further, the middle part of the horizontal frame 9 is coupled to the link coupling portion between the tie rod 13 and the tension rod 12 via the tilt cylinder 15.
[0009]
As shown in FIG. 4, sprockets 6 and 7 are arranged at both longitudinal ends of the horizontal frame 9, and an endless chain, which will be described later, with a sprocket (not shown) provided inside the elevator column 11. 19 is held. A guide rail 18 is attached to the horizontal frame 9 via a pair of front and rear connecting members 45.
[0010]
As shown in FIG. 5, the guide roller 20 attached to the bucket 3 meshes so that the endless chain 19 can be guided around the guide rail 20. Further, the total distance between the three sprockets described above is substantially the same before and after the swing cylinder 10 is operated and the horizontal frame 9 is moved up and down. Two sprocket positions are set.
[0011]
Here, the horizontal frame 9 has a slidable inner cylinder 8 so that a constant tension is applied to the endless chain 19 by a cylinder (not shown) against the extension of the chain and a slight length change when the swing arm is operated. It has become. In addition, a plurality of buckets 3 are attached to the endless chain 19 by pin coupling, and the loose material 5 can be scraped off by the bucket 3 as the endless chain 19 rotates.
[0012]
On the other hand, as shown in FIG. 5, the load cell 21 is attached to one link coupling portion 45 of the pair of link coupling portions 45 that couple the support frame 23 that supports the guide rail 18 from behind and the horizontal frame 9. ing. Reference numeral 22 denotes a connecting pin.
As shown in FIG. 1, the front load cell 21A attached to the front link coupling portion 45A and the rear load cell 21B attached to the rear link coupling portion 45B each detect an upward load acting on the bucket. The load detected by the load cells 21A and 21B is input to a PLC (hereinafter referred to as a control device) 24.
[0013]
As shown in FIG. 3, the control device 24 includes an input value (input load) 101 at the front portion of the horizontal frame inputted from the front load cell 21A and a set load 103 relating to the front portion of the frame inputted from a setting device (not shown). , And PI control is performed so that the deviation becomes zero, and the control signal 105 is output to a proportional solenoid valve for a tilt cylinder, which will be described later, while the horizontal frame input from the rear load cell 21B The deviation between the sum of the input value (input load) 102 and the input value (input load) 101 of the front portion of the horizontal frame input from the front load cell 21A and the set load 104 related to the entire frame input from a setting device (not shown) is The PI control is performed so that it becomes zero, and the control signal 106 is output to a swing cylinder proportional solenoid valve described later. There.
[0014]
A swing circuit 25 is connected to the swing cylinder 14. The swing circuit 25 includes a drive circuit 33 that enables the cylinder rod 44 to extend and contract and a self-weight reducing circuit 34. The drive circuit 33 serving as a drive system includes a switching valve 28 that expands and contracts the horizontal frame by expanding and contracting the cylinder rod 44 by switching the hydraulic pressure inlet of the swing cylinder 14.
[0015]
The self-weight reducing circuit 34 is provided so as to bypass the drive circuit 33, and the hydraulic pressure generated by the hydraulic pump 27 is supplied to the rod-side hydraulic pressure in the swing cylinder 14 via the proportional solenoid valve 31 and the switching valve 29. It is configured so that it can be introduced into the introduction port 35. The proportional solenoid valve 31 is a pressure reducing valve that also serves as a relief valve, and has a structure that variably controls the pressure on the secondary side in accordance with an electrical command signal from the control device 24.
[0016]
Thus, when the switching valve 29 is operated, the hydraulic pressure controlled by the control device 24 acts on the cylinder rod 44 side. As a result, when the swing cylinder 14 is operated to be contracted by raising the ship bottom, oil controlled by the control device 24 flows into the hydraulic pressure inlet 35 side. On the other hand, when the ship bottom descends, the oil on the cylinder rod 44 side is released from the proportional solenoid valve 31 to the tank 36 by the pressure controlled by the control device 24.
[0017]
A reservoir tank 38 is connected to the hydraulic pressure inlet 37 on the head side in the swing cylinder 14 via a switching valve 30. For this reason, since the switching valve 30 is open when the self-weight reducing circuit 34 is operated, the oil on the cylinder head side is free between the reservoir tank 38 and the hydraulic pressure inlet 37 according to the movement of the cylinder rod 44. Inflow and outflow.
[0018]
On the other hand, the tilt circuit 15 is also connected to the same hydraulic circuit as the swing circuit 25, that is, the tilt circuit 26, so that the horizontal frame can follow the tilting of the hull.
As shown in FIG. 2, the tilt circuit 26 includes a drive circuit 33 'that allows the cylinder rod 44' to expand and contract and a self-weight reduction circuit 34 '. The drive circuit 33 'serving as a drive system includes a switching valve 28' that expands and contracts the cylinder rod 44 'to rotate the horizontal frame by switching the hydraulic pressure inlet of the tilt cylinder 15.
[0019]
The self-weight reducing circuit 34 'is provided so as to bypass the drive circuit 33', and the hydraulic pressure generated by the hydraulic pump 27 is supplied to the rod in the tilt cylinder 15 via the proportional solenoid valve 31 'and the switching valve 29'. It is configured to be able to be introduced into the hydraulic pressure inlet 35 'on the side. This proportional solenoid valve 31 ′ is a pressure reducing valve that also serves as a relief valve, and has a structure that variably controls the pressure on the secondary side in accordance with an electrical command signal from the control device 24.
[0020]
Thus, when the switching valve 29 'is operated, the hydraulic pressure controlled by the control device 24 acts on the cylinder rod 44' side. Accordingly, when the tilt cylinder 15 is actuated to contract by tilting the ship bottom, the decompressed oil flows into the hydraulic pressure inlet 35 'side. On the other hand, when the tilt cylinder 15 is extended, the oil on the cylinder rod 44 ′ side is released from the proportional solenoid valve 31 ′ to the tank 36 ′ by the pressure controlled by the control device 25.
[0021]
A reservoir tank 38 ′ is connected to a hydraulic pressure introduction port 37 ′ on the head side in the tilt cylinder 15 via a switching valve 30 ′. For this reason, since the switching valve 30 'is open when the self-weight reducing circuit 34' is operated, the oil on the cylinder head side causes the reservoir tank 38 'and the hydraulic pressure inlet 37' to move according to the movement of the cylinder rod 44 '. Oil freely flows in and out between them.
[0022]
A case where the continuous unloader configured as described above is applied to bottom-up work will be described.
FIG. 8 is an operation explanatory diagram showing a state in which the continuous unloader collects the bulk material remaining on the bottom of the ship. In the ship 4, the bulk material 5 is mostly landed, and a small amount of bulk material 5 is present on the bottom 55. It remains.
[0023]
In a state where a considerable amount of loose objects remains in the hold, the switching valve 29 and the switching valve 30 are in the closed position, and by operating the switching valve 28, the swing cylinder 14 is expanded and contracted to move the position of the horizontal frame 9. The switching valve 28 is closed at an arbitrary position and the scraping operation is performed. When the ship's bottom approaches, a switch (not shown) is turned on. Then, the solenoids of the switching valve 29 and the switching valve 30 are energized, and both valves are switched to the open state. At the same time, the command current of the control device 24 flows to the proportional solenoid valve 31 and the self-weight reducing circuit 34 is activated.
[0024]
Therefore, when the ship bottom of the hull 56 moves up and down under the influence of waves or the like, the control device 24 loads the load 102 at the rear of the horizontal frame input from the rear load cell 21B and the load 101 at the front of the horizontal frame input from the front load cell 21A. And the control signal 106 is output to the proportional solenoid valve 31 of the swing circuit 25. The PI control is performed so that the deviation between the sum of the above and the set load 104 related to the entire horizontal frame input by the setter (not shown) becomes zero. As a result, oil controlled by the control device 24 flows into the hydraulic pressure inlet 35 side of the swing cylinder 14, and the horizontal frame 9 flexibly follows up and down of the ship bottom 55.
[0025]
FIG. 9 is a state explanatory view showing a state in which the continuous unloader follows the hull in which tilting has occurred. When the bottom is set up, the self-weight reducing circuit 34 ′ of the tilt circuit 26 is operated similarly to the swing circuit 29. deep.
When tilting occurs in the ship, the control device 24 reads the deviation between the load 101 at the front of the horizontal frame input from the front load cell 21A and the set load 103 related to the front of the frame input by a setting device (not shown). Since PI control is performed so that the deviation becomes zero and the control signal 105 is output to the proportional solenoid valve 31 ′ of the tilt circuit 26, the fluid pressure introduction port 35 ′ side of the tilt cylinder 15 is controlled by the control device 24. Oil flows in and the horizontal frame 9 flexibly follows the tilt of the ship bottom.
[0026]
In the above description, the case where the tilt cylinder 15 is disposed between the link coupling portion where the tie rod 13 and the tension rod 12 are coupled and the middle part of the horizontal frame 9 is described, but as shown in FIG. The tilt cylinder 15 may be directly attached between the swing arm 10 and the rear end of the horizontal frame 9.
[0027]
【The invention's effect】
As described above, the present invention directly detects the load acting on the bucket by the pair of front and rear load cells provided on the horizontal frame, and always installs the swing cylinder and tilt cylinder so that the reaction force of the bucket becomes a set value. In order to control, the hull is flexibly followed up and down and tilted, and a constant reaction force always acts on the bucket.
[0028]
In other words, since the swing cylinder responds to the vertical movement of the hull and the tilt cylinder follows the tilt of the hull, even if the hull is tilted, it is always grounded by a plurality of buckets. Without this function, the full load is borne only at the rear end or the front end of the bucket row, and an excessive load acts on the bucket and the bottom of the ship.
[Brief description of the drawings]
FIG. 1 is a structural explanatory view showing a structure of a continuous unloader according to the present invention and a hydraulic circuit used in the unloader.
FIG. 2 is a diagram illustrating the structure of a tilt circuit.
FIG. 3 is a diagram illustrating the structure of a control device.
FIG. 4 is an enlarged side view of a main part of a continuous unloader according to the present invention.
5 is a cross-sectional view taken along line VV in FIG.
6 is an enlarged view of a main part of FIG.
FIG. 7 is an overall configuration diagram illustrating a state in which a bulk material loaded on a ship is landed using a continuous unloader.
FIG. 8 is a state explanatory view showing a state in which a continuous unloader follows a hull in which vertical movement has occurred.
FIG. 9 is a state explanatory view showing a state in which a continuous unloader follows a hull in which tilting has occurred.
FIG. 10 is a side view showing another example of a continuous unloader.
[Explanation of symbols]
3 Bucket 9 Scraping frame 10 Swing arm 14 Swing cylinder 15 Tilt cylinder 19 Endless chain 21A, 21B Load cell 24 Controller 101 Load 102 detected by front load cell 102 Load detected by rear load cell 103 Set load 104 related to frame front Set load related to the whole

Claims (1)

A scraping frame is attached to a swing arm rotated by a swing cylinder, a tilt cylinder for tilting the scraping frame is attached to the swing arm, and an endless chain that circulates around the scraping frame and the swing arm. In the continuous unloader in which a plurality of buckets are attached to the scraper frame, the scraping frame includes a pair of front and rear load cells for detecting a load acting on the bucket, and is set in advance as a sum of the loads detected by the load cells. Deviation between the control system that controls the swing cylinder thrust and the load detected by the front load cell so that the deviation from the set load related to the entire frame is zero, and the preset set load related to the front of the frame Control system that controls tilt cylinder thrust so that the value becomes zero Continuous unloader, characterized in that it comprises a controller having.

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