JPH0660500B2 - Cutter of pump dredger-rotation speed control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cutter rotation speed control device for a pump dredging ship, which performs a dredging work while swinging around a spud as a swing center.

[Prior Art] A pump dredger will be described with reference to FIGS. 4 and 5.
The bow of the hull 1 is provided with a ladder 3 having a cutter 2 for excavating water bottom sediment at the tip, and the ladder 3 is elevated by a ladder winch and a wire rope (not shown). Electric cutter motor 4
It is designed to be driven by rotation.

On the bow, wire ropes 5 and 6 diagonally forward from this.
Is stretched, and the tips of the wire ropes 5 and 6 are fixed to the water bottom by anchors 7 and 8. The base ends of the wire ropes 5 and 6 are wound around swing winches 11 and 12 which are rotated by motors 9 and 10.

The stern of the hull 1 is provided with a pile-like spud 13 which is driven to the bottom of the water and serves as a swing center for swinging the bow provided with the rudder 3. Thus, the swing winch 11,1
When one of the two is wound and the other is unwound, the hull 1 swings around the spud 13.

Further, the hull 1 is provided with a gyro compass 14 for detecting the turning direction of the hull 1. In order to stop the cutter 2 at the right and left crossing positions 15 and 16 preset as the dredging width, the gyro compass 14 is provided. An automatic speed reducer is provided to gradually reduce the swing speed from the set swing speed deceleration start positions 17 and 18. Therefore, the cutter 2 provided on the rudder 3 which is swung between the right and left offset positions 15 and 16 excavates the water bottom while moving along the swing trajectory of the hull 1, and the excavated earth and sand are excavated by a dredging pump and an unillustrated dredging pump. It is discharged by the discharge pipe.

[Problems to be Solved by the Invention] As described above, the swing speed, the pump rotation speed, and the like are conventionally controlled during dredging, but the rotation speed of the cutter is often kept constant. , The mass of excavated earth and sand is large when the swing speed is fast, and small when the swing speed is slow,
Since these earth and sand pass through the inside of the dredging pump and are discharged through the discharge pipe of 3000 to 4000 m, there is a problem that the discharge pressure, suction pressure, flow velocity, etc. of the pump are likely to change.

The present invention controls the number of rotations of the cutter in accordance with the swing speed to make the size of the lump of excavated soil uniform and to perform constant control of the amount of dredged soil.

[Means for Solving Problems] The present invention relates to a cutter trajectory display device that detects a swing speed of a cutter by a signal such as a gyro compass, a setting device that sets the width of excavated soil, and a signal from the setting device. And a calculator that calculates an appropriate cutter rotation speed based on a signal from the cutter trajectory display device, and a cutter controller that controls the rotation speed of the cutter motor based on the signal from the calculator. Have.

[Operation] Therefore, an appropriate cutter rotation speed corresponding to the swing speed of the cutter is obtained by the arithmetic unit, the rotation speed of the cutter motor is controlled, and the constant amount of dredged soil can be controlled.

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

FIG. 1 is a block diagram of a cutter rotation speed control device of the present invention. Reference numeral 19 indicates the cutter 2 based on the azimuth detected by the gyrocompass 14 and the swing diameter R (see FIG. 5).
Is a cutter trajectory display device for obtaining the peripheral speed of the cutter, that is, a swing speed v, and 20 is a swing speed v from the cutter trajectory display device 19, an excavated sand width t from the setting device 21 (see FIG. 2), An arithmetic unit for obtaining an appropriate cutter rotation speed N from the number B of blades 22 attached to the cutter 2 (see FIG. 3) and outputting this value as a corresponding analog signal. Is a cutter controller that controls the rotation speed of the cutter motor 4 based on the signal of.

In such a configuration, first, the cutter trajectory display device 19 calculates the azimuth of the hull 1 detected by the gyro compass 14 and the swing diameter R of the hull 1 obtained by the measurement to obtain the swing speed v. The swing diameter R
As shown in FIG. 5, the distance R ₁ from the spud 13 to the front end 24 of the spud carriage well (measured by a spud carriage position indicator (not shown)) and the trunnion pin 25 of the ladder 3 from the front end 24 of the spud carriage well.
A distance R ₂ to, those obtained from the plane length R ₃ Metropolitan ladder 3 performs correction such as trim heel.

Generally, as shown in FIG. 3, the cutter 2 has a blade.
22 is attached, and the blade 22 excavates water bottom sediment, but as shown in FIG. 2, the amount of excavated sediment is t × h
It can be expressed as xy (m ² ). In addition, "a" indicates a swing direction, "b" indicates a forward direction, and "c" indicates a depth direction. Here, h is the excavated soil thickness, which is determined by the amount of descent of the ladder 3, and y is the length of excavated soil, which is a value determined by the extrusion amount of the spud carriage (not shown). Further, t is the width of the excavated sediment, and the swing speed v (m
/ Min) and the rotation speed N (rpm) of the cutter 2, that is, the blade
It is a value determined by the number of times 22 hits the earth and sand. Therefore, the width t of the excavated sediment is given by the following equation.

However, B: the number of blades 22 (which is a constant value depending on the specifications of the cutter 2) Therefore, the value of t is set by the setter 21 and input to the calculator 20. The calculator 20 obtains an appropriate value of N from the above equation, and N
The analog signal corresponding to is output to the cutter controller 23,
The rotation speed of the cutter motor 4 is controlled based on this value.

By the way, when the cutter 2 comes close to the right or left off-positions 15 and 16, the swing speed is decelerated and eventually stops, so in this case, the setting device 21 is preset to the cutter 21 so that the cutter motor 4 does not stop. The cutter minimum rotation speed N'is set in advance, and when N obtained by the above equation becomes smaller than N ', the cutter motor 4 is operated at the rotation speed N'.

In the present invention, as described in the above embodiment, the rotation speed of the cutter 2 is controlled from the swing speed, but instead of the cutter rotation speed, the bucket rotation speed of the bucket dredger that has a spud and swings to dredge. It can also be applied to control.

[Effects of the Invention] As described above, according to the present invention, (i) since the size of a mass of excavated soil can be dredged evenly, there is less opportunity for stones to be clogged in the dredging pump, and the dredging pump can be opened. It is possible to improve the dredging efficiency by reducing the interruption of dredging.

(ii) Since the size of the lumps is uniform, fluctuations in the suction and discharge pressures of the dredging pump and the flow velocity in the discharge pipe are small, the dredging state can be stabilized, and the amount of excavated soil can be increased. You can

(iii) Since the soil thickness excavated by the cutter is always constant, when the uniform soil is dredged, the cutter is less likely to be abnormally loaded, and the cutter is less worn and has a longer life.

And so on.

[Brief description of drawings]

FIG. 1 is a block diagram of a cutter rotation speed control device of the present invention, FIG. 2 is an explanatory view of excavated earth and sand, FIG. 3 is an explanatory view of a cutter, FIG. 4 is a schematic plan view of a pump dredger, and FIG. It is a schematic side view of a pump dredger. 1 is a hull, 2 is a cutter, 3 is a ladder, 4 is a cutter motor, 13 is a spud, 14 is a gyro compass, 19 is a cutter trajectory display device, 20 is a calculator, 21 is a setting device, and 23 is a cutter controller. .

Claims (1)

[Claims] Claims: 1. A pumping dredger in which a cutter is rotated while swinging around a spud as a swing center to perform dredging work, and a cutter trajectory display device for detecting the swing speed of the cutter by a signal such as a gyro compass, and excavation. A setter for setting the width of the earth and sand, a calculator for calculating an appropriate cutter rotation speed based on a signal from the setter and a signal from the cutter trajectory display device, and a cutter motor based on the signal from the calculator And a cutter controller for controlling the rotation speed of the cutter, the cutter rotation speed control device for a pump dredger.