JP6890343B2 - Dredging method using a dredging machine - Google Patents

Description

The present invention relates to a dredging method using a dredging machine equipped on a dredging vessel.

In the harbor area, dredging vessels are used for dredging work to maintain the water depth of the harbor and the shipping lane, and to dig down the seabed of the shipping lane to accommodate vessels that are getting larger year by year. There is a work boat called a dredger, which is equipped with a dredger, for example, a swivel hoist, at the front of a steel box-shaped hull. In the dredging work, a grab bucket (hereinafter, simply referred to as "bucket") suspended from the sheave at the tip of the jib is lowered to the seabed, the earth and sand on the seabed is picked up, and the earth and sand is placed on the earthen carrier next to the dredger. To load.
In recent years, while CO ₂ environmental problems and energy-saving measures have been highlighted, some inventions in which energy-saving measures have been applied to such dredging vessels and dredging machines have been proposed (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-72178

However, according to the claim, Patent Document 1 states that "a drenching vessel having an excavation means for excavating an object to be drought, the motor for driving the excavation means, an engine generator for generating electric power, the motor and the engine". A first converter provided between the generator and adjusting the electric power generated by the engine generator, and an inverter provided between the motor and the first converter to control the operation of the motor. A second converter provided in parallel with the engine generator and storing the regenerated electric power from the motor, and a second converter provided between the inverter and the electric storage device to adjust the electric power sent from the electric storage device. The content of the invention is that the position energy of the grab bucket when the bucket is unwound is converted into electrical energy and stored in the electric storage device, and the engine output at the time of hoisting is assisted by the motor. Staying.

The dredging work is a work performed while repeating one cycle of bucket winding (bucket lowering) → bucket closing → ground cutting → bucket hoisting → turning → bucket opening → turning. The load value on the engine varies greatly depending on each process. The load is most applied in the one-round process at the time of "ground cutting", which is the initial stage of the bucket hoisting process. In addition to the inertial force of both the weight of the grab bucket and the contents, the maximum load is applied by the adsorption force of the seabed. The dredger large engine is selected to accommodate this maximum load, a large diesel engine, which is also 2500 horsepower, for example, 30 m ³ class dredger is mounted.
However, depending on the dredging depth, the output is large, which is required only in about 1/4 of the work cycle. It is an output that is not necessary except for ground cutting and hoisting. Since the engine of the dredging machine is operated at a substantially constant rotation speed during the dredging work, there is a problem that a certain amount of fuel is consumed even when the engine load is small.

The present invention solves the above problems, recovers and stores excess output energy of the engine at low load, and utilizes this for engine assist at high load to save energy and further reduce the size of the engine. It is an object of the present invention to provide a dredging method using a dredging machine that also enables.

In order to achieve the above object, the gist of the invention according to claim 1 is to attach a jib protruding from a swivel body and a wire to the jib, and suspend a grab bucket on the tip side of the wire. A support drum provided with a drum portion that winds the wire base end side so that the winding and winding can be performed, and a crank shaft that drives the rotation are connected to the support drum via a first clutch, and the support drum is connected. To the support drum via the fourth clutch, the engine for rotating the engine, the surplus output recovery generator that is connected to the crank shaft via the third clutch, and collects the surplus output of the engine and supplies it to the storage battery. Bucket unwinding, bucket closing, bucket hoisting, using a dredger equipped with an assist motor that is connected and uses the energy stored in the storage battery to support the rotational movement of the support drum by the engine. While the steps of turning, opening the bucket, and turning proceed in sequence, the assist motor supports the rotational movement of the support drum by the engine during the hoisting process of the grab bucket, while outside the hoisting process of the grab bucket. In the process of, the surplus output energy of the engine is recovered by the surplus output recovery generator and stored in the storage battery, and further, the engine is output in a high efficiency range of fuel efficiency at the working speed of the engine. The surplus output energy of the engine is recovered by the surplus output recovery generator and stored in the storage battery, and in addition, the hull-side generator that operates the hull movement spud is the storage battery. By using the spud with the hull-side generator, the drenching location is sequentially shifted to perform the drenching work at a new location, and the hull-side generator is operated even when the hull movement is stopped, and the surplus power is generated. There is a dredging method using a dredging machine, which is characterized in that the above-mentioned storage battery is supplied to the storage battery.

(Action)
As in the present invention, when the engine surplus output during processes other than the ground cutting and bucket hoisting processes is recovered and stored, and this is used (assisted) for the ground cutting and bucket hoisting processes that require a large amount of energy, Since the high load range is cut, an engine with a small maximum output can be selected. The engine can be made compact and the equipment cost of the dredging machine can be reduced compared to the conventional one. Then, by storing the output of the engine when the workload is low, the engine can always be used in the output range with good fuel efficiency. By averaging the engine output, it becomes possible to use the engine in the high fuel efficiency range. The running cost (fuel cost) can be suppressed as well as the initial cost (equipment cost).
The fuel consumption varies depending on the load on the engine, and the consumption can be obtained by a graph called the fuel consumption rate, which is a graph of the engine-specific output and the fuel consumption (FIG. 11). From this graph, when the high efficiency range of fuel consumption in the working rotation speed of the engine is obtained and the engine is operated with its output kept substantially constant in the high efficiency range (the engine output is shown by a broken line in FIG. 12), the engine is operated. In the low load time zone, which occupies most of the above, the surplus output up to the high efficiency range can be recovered and stored in the storage battery. At the same time, fuel efficiency can be improved. Then, by supplying the energy stored in the storage battery as a drive source of the assist motor at the time of ground cutting or bucket hoisting in a high load time zone, it becomes possible to assist the engine output using the regenerative energy. The total fuel consumption is reduced, and the engine output at the time of ground cutting and bucket hoisting when the load peaks is suppressed, which leads to the miniaturization of the engine.
In addition, when the surplus power of the hull-side generator is recovered, the energy saving that is more effective is achieved by organically interacting with the hull-side generator and the diesel engine for the dredger, which has been considered separately in the past. Can be done.

The dredging method using the dredging machine of the present invention maintains the combustion efficiency of the engine in a highly efficient state, recovers and stores excess output energy, and can assist the engine under heavy load, thus making it possible to reduce the running cost. This leads to environmental measures and energy saving measures, and also makes it possible to reduce the size of the engine.

It is one form of a dredging method using a dredging machine , and is a schematic explanatory view in which the dredging machine is in the bucket unwinding process. It is a schematic explanatory view that the dredging machine of FIG. 1 is at the time of ground cutting at the initial stage of the bucket hoisting process. It is a schematic plan view of the dredging machine of FIG. It is a time chart diagram which shows the change in each process of the dredging method using the dredging machine of FIG. It is explanatory drawing which shows the linkage operation and energy flow of each device by the control means in the bucket unwinding process. It is explanatory drawing which shows the linkage operation and energy flow of each device by the control means in a bucket closing process. It is explanatory drawing which shows the linkage operation and energy flow of each device by the control means in the bucket hoisting process including the time of ground cutting. It is explanatory drawing which shows the linkage operation and energy flow of each device by the control means in a bucket turning process. It is explanatory drawing which shows the linkage operation and energy flow of each device by the control means in a bucket opening process. It is explanatory drawing which shows the linkage operation and energy flow of each device by the control means in a bucket turning process. It is explanatory drawing which shows the fuel consumption with respect to the engine output. It is explanatory drawing of the relationship between surplus energy and regenerative energy which makes up for the shortage of engine output with respect to the energy required for dredging work. It is a control flowchart of the control circuit in one Embodiment of this invention. It is a top view of the dredging machine of another aspect alternative to FIG. It is a top view of the dredging machine which concerns on the dredging method using the dredging machine of this invention .

Hereinafter, the dredging method using the dredging machine according to the present invention will be described in detail. FIG. 15 is a form of a dredging method using the dredging machine of the present invention, FIG. 1 is a schematic explanatory view of the dredging machine in the bucket unwinding process, and FIG. 2 is a schematic explanatory view of the dredging machine of FIG. 1 at the time of ground cutting. 3 is a schematic plan view of the dredging machine of FIG. 1, and FIG. 4 is a time chart diagram showing changes in each process using the dredging machine of FIG. 1. 5 to 10 are explanatory views showing the linked operation and energy flow of each device by the control means in each process, FIG. 5 shows a bucket unwinding process, FIG. 6 shows a bucket closing process, and FIG. 7 includes ground cutting. The bucket hoisting process, FIG. 8 shows a swivel process, FIG. 9 shows a bucket opening process, and FIG. 10 shows an explanatory diagram in a swivel process. FIG. 11 is an explanatory diagram of fuel consumption with respect to engine output, FIG. 12 is an explanatory diagram of the relationship between surplus energy and regenerative energy that supplements engine output, FIG. 13 is a control flowchart of a control circuit, and FIG. FIG. 15 shows a plan view of the dredging machine according to the dredging method using the dredging machine of the present invention. Each figure is a simplified diagram, and the control means CR is omitted except for FIGS. 3, 5, and 15, and devices, parts, and the like that are not directly related to the present invention are omitted.

(1) Dredging machine The dredging machine M is equipped on the dredging vessel D, and is equipped with a jib J, a support drum 11, an opening / closing drum 21, an engine 61, a surplus output recovery pump 31, an assist motor 41, a control means CR, and a position energy recovery hydraulic pressure. It includes a pump 51 and a dredging generator 71 (generator on the hull side) for moving the hull (FIGS. 1 and 15 ).
The jib J is a boom in which the base end portion is attached to the swivel body 91 of the dredging machine M and is projected diagonally upward from the swivel body 91 in order to lift the grab bucket G that has grasped the earth and sand E. At the tip of the jib J, a sheave SV, which is a guide wheel that changes the direction of the wire 15 and the wire 25, is attached in order to wind up and down the bucket G.

The support drum 11 has a drum portion such that a wire 15 is attached to a jib J, a bucket G is suspended on the tip side of the wire, and the bucket G can be raised and lowered (also referred to as “bucket hoisting, bucket hoisting”). This is a bucket holding main drum around which the base end side of the wire is wound around 110 (FIGS. 1 and 5). The wire 15 supports the bucket G in an ascending / descending manner by winding and manipulating the wire 15 via the jib J and the sheave SV.

The opening / closing drum 21 is a bucket opening / closing drum in which the wire 25 is attached to the jib J, the wire tip side is connected to the bucket G, and the wire base end side is wound around the drum portion 210 so that the bucket G can be opened / closed. (Figs. 1 and 5). The wire 25 can open and close the bucket G by winding and manipulating the wire 25 via the jib J and the sheave SV. Although the opening / closing drum 21 is used for opening / closing the bucket G, for example, a device for opening / closing the bucket G using an electric motor may be attached. Further, a hydraulic tube may be arranged from the swivel body 91 to the point of the bucket G, and the bucket G may be opened and closed by using hydraulic pressure.

The crankshaft 610 (including the drive shaft 611 connected to the crankshaft 610) of the engine 61 is connected to the support drum 11 via the first clutch 19 and to the open / close drum 21 via the second clutch 29, respectively. It is an engine that rotates both or one of the support drum 11 and the opening / closing drum 21 (FIG. 3). Here, the diesel engine 61 is adopted, and the crankshaft 610, which converts thermal energy into kinetic energy and drives it to rotate, rotates the support drum 11 and the opening / closing drum 21. The crankshaft 610 is connected to the torque converter 65 on one end side, and the engine drive shaft 611 is connected to the drum rotation shaft 111 via the first clutch 19 via a transmission device 66 such as a speed reducer. The support drum 11 rotates by the drive rotation of the crankshaft 610. Further, the engine drive shaft 611 is connected to the drum rotation shaft 211 via the second clutch 29 via a transmission device 66 such as a speed reducer and a gear mechanism, and the opening / closing drum 21 rotates by the drive rotation of the crankshaft 610.

The surplus output recovery pump 31 is a machine that gives energy to the liquid by supplying surplus power from the engine 61. The pump 31 is connected to the other end side of the crankshaft 610 via a third clutch 39 to recover the surplus output of the engine 61 and supply it to the accumulator 80 (FIG. 3). The crankshaft 610 is drive-connected to the surplus output recovery pump 31 via the third clutch 39, and the surplus output recovery pump 31 recovers the surplus output of the engine 61. The recovered regenerative energy is sent to the accumulator 80. The regenerative energy referred to in the present invention includes not only energy that converts kinetic energy into electrical energy and recovers it, but also energy that converts kinetic energy into hydraulic energy and recovers it.
The surplus output recovery pump 31 is a surplus output recovery hydraulic pump that converts the surplus output of the engine 61 into hydraulic energy and supplies it to the accumulator 80, and employs a variable displacement hydraulic pump. This is because the discharge amount can be controlled by the control means CR described later, and the discharge amount and energy consumption can be made variable. It can do the same job with less engine horsepower than a fixed-capacity pump and consume less fuel.
In the present embodiment, the surplus output recovery pump 31 recovers the surplus output of the engine 61 and supplies it to the accumulator 80. The surplus output of the engine 61 is connected to the crankshaft 610 via the third clutch 39. It can also be used as a surplus output recovery generator that is recovered and supplied to the storage battery BT.

The assist motor 41 is a prime mover that is connected to the support drum 11 via the fourth clutch 49 and rotates using the energy stored in the accumulator 80 or the storage battery BT, and supports the rotational movement of the support drum 11 by the engine 61. To do.
Here, the assist hydraulic motor 41 rotates by using the energy stored in the accumulator 80 as a drive source. The assist hydraulic motor 41 is connected to the rotating shaft 111 of the support drum 11 via the fourth clutch 49. When hydraulic pressure is supplied from the accumulator 80 and the assist hydraulic motor 41 is driven and rotated, and the rotation speed exceeds the rotation speed of the support drum 11 by the engine 61, the fourth clutch 49 is engaged and the support drum 11 is engaged. Assists rotation.
When the surplus output of the engine 61 is recovered by the surplus output recovery generator instead of the surplus output recovery hydraulic pump 31 and supplied to the storage battery BT, an assist electric motor is used instead of the assist hydraulic motor 41. Used.

The control means CR rotates the assist motor 41 when the bucket G is hoisted, and causes the surplus output recovery pump 31 to recover the surplus output energy of the engine 61 during the operating time of the bucket G other than when the bucket G is hoisted. It is a controller that accumulates in the accumulator 80 or collects it in the surplus output recovery generator and stores it in the storage battery BT. The excess output energy of the engine 61 is stored in the accumulator 80 (or the storage battery BT) during the operating time of the grab bucket G where the workload of the engine 61 is low, and the operating time of the grab bucket G where the workload is high, specifically. Is incorporated into the control circuit so that the assist motor 41 supports (assists) the rotational movement of the support drum 11 by the engine 61 at the time of ground cutting and hoisting.
The assist motor 41, the fourth clutch 49, the surplus output recovery pump 31, and the third clutch 39 are each connected to a controller which is a control means CR having a built-in CPU, and the controller is an operation signal of a driver lever in the driver's seat. Controls the energization of the assist motor 41, the fourth clutch 49, the surplus output recovery pump 31, and the third clutch 39 based on the above. FIG. 13 shows a control flowchart of those control circuits. The drive procedure of the assist motor 41 and the surplus output recovery pump 31 is shown. When the engine 61 is driven, the operation lever operation signal is read in step 101, and the bucket hoisting operation is not applicable in the following step 102, The surplus output recovery pump 31 is turned on, the third clutch 39 is turned on, the assist motor 41 is turned off, and the fourth clutch 49 is turned off (step 103). On the other hand, when the bucket hoisting operation is applicable in step 102, the assist motor 41 is turned on, the fourth clutch 49 is turned on, the surplus output recovery pump 31 is turned off, and the third clutch 39 is turned off (). Step 104). Thus, by turning on / off the assist motor 41, the fourth clutch 49, the surplus output recovery pump 31, and the third clutch 39, when the energy required for the dredging operation is smaller than the engine output as shown in FIG. 12, the surplus It recovers energy and supplies regenerative energy when the required energy is insufficient for the engine output. With respect to the required energy curve, the assist motor 41 using the regenerative energy supports the shortage at the time of hoisting the bucket, which is not enough with the engine output operated at the high fuel efficiency efficiency point, and obtains nothing.

The control means CR of the present embodiment uses the surplus output energy of the engine 61 as the surplus output recovery pump 31 during the operating time of the bucket G such as bucket unwinding, bucket closing, turning, and bucket opening when the workload of the engine 61 is low. Collects and accumulates in the accumulator 80. The surplus output energy of the engine is recovered by the surplus output recovery pump 31 as regenerative energy and sent to the accumulator 80, where the surplus output energy is stored. Then, in the operating time zone of the bucket winding including the ground cutting where the workload of the engine 61 is high, the assist motor 41 using the energy accumulated in the time zone when the workload of the engine 61 is low is driven and rotated to drive and rotate the engine. It is controlled to support the rotational movement of the support drum 11 by 61. The control means CR is a sensor (governor opening sensor, pressure sensor of accumulator 80, wire tension sensor, wire tension sensor, rotation sensor of support drum 11, rotation of opening / closing drum 21) attached to each part of the dredger M. It also controls each hydraulic valve, the discharge amount of the surplus output recovery pump 31, the first to fifth clutches 19, 29, 39, 49, 59, etc. based on the information of the sensor, the turning position sensor, etc.). The dredging operation proceeds by the operation of the bucket opening / closing operation lever, the turning operation pedal, and the like in addition to the operation of the operation lever, and a known control circuit is incorporated for these operations.

As described above, the main task of the engine 61 is to rotate the support drum 11 when hoisting the bucket, but the excess energy of the engine 61 is not simply released and lost during most of the processes that do not require the task, but is dredged. The control means CR, which is the control device of the machine M, is activated to recover the surplus output recovery pump 31 as regenerative energy to the accumulator 80 (FIG. 12). Then, the regenerative energy is used as a drive source for the assist motor 41 and used when the engine load is high, so that the engine 61 is miniaturized. In addition, the engine 61 is operated in a high efficiency range with its output kept substantially constant to improve fuel efficiency.

The present embodiment further includes a potential energy recovery hydraulic pump 51. The rotational power of the support drum 11 which is connected to the support drum 11 via the fifth clutch 59 and transmits the position energy when the grab bucket is lowered is converted into hydraulic energy and recovered, and the hydraulic energy is supplied to the accumulator 80. The position energy recovery hydraulic pump 51 is further provided. When the control means CR works to lower the bucket G having a large mass (when the bucket is unwound), the potential energy is converted into flood control by the potential energy recovery hydraulic pump 51 and recovered. The position energy recovery hydraulic pump 51 converts the rotational power of the support drum 11 which is connected to the support drum 11 via the fifth clutch 59 and transmitted by the potential energy when the bucket is lowered (bucket unwinding) into high pressure hydraulic energy. The hydraulic energy is collected and supplied to the accumulator 80. The potential energy recovery is transmitted and boosted through the fifth clutch 59 connected to the rotating shaft 111 of the support drum 11.
In the figure, reference numeral 81 is a hydraulic pipe, reference numeral 82 is a check valve, reference numeral 84 is a control valve, reference numeral 92 is a swivel gear, reference numeral 93 is a turning motor, and reference numeral S is a sea surface.

FIG. 14 is a dredging machine M of another aspect, and shows a plan view corresponding to FIG. In FIGS. 1 to 13, the assist motor 4 and the potential energy recovery hydraulic pump 51 are provided separately, but both are combined into a hydraulic pump motor to simplify the device (dredging machine M). The assist hydraulic motor 41 and potential energy recovery hydraulic pump 51 are used. Therefore, the fourth clutch 49 and the fifth clutch 59 are combined into one clutch.

FIG. 15 is a dredging machine according to a dredging method using the dredging machine of the present invention, and shows a plan view corresponding to FIG. Some dredger D in the present invention has a hull towed. Nevertheless, the dredging vessel D includes a hull moving diesel engine 70 and a hull moving diesel generator (hereinafter, also referred to as “hull side generator”) 71 as shown in FIGS. 1 and 15. The hull-side generator 71 of FIG. 15 is a drive source for operating the hull-moving spud SP shown in FIG. The hull-side generator 71 finishes the dredging work at one place in, for example, about 30 minutes, and then moves to a slightly shifted place using the spud SP. After that, the dredging work is completed while the movement is stopped for about 30 minutes, and the movement to a slightly shifted place is repeated. While the ship is stopped for about 30 minutes, the ship is not moved, but it is also used for cabin lighting, GPS personal computer, etc., and the generator 71 is operating. Therefore, a seventh electric motor 72 for driving the seventh hydraulic pump 73 for recovering the surplus electric power while the hull is stopped moving and supplying it to the accumulator 80 is provided. The surplus electric power recovery electric circuit 95 is connected to the seventh electric motor 72 installed on the swivel body 91 from the generator 71 installed on the hull side through the slip ring 910 of the swivel body 91. The seventh electric motor 72 collects the surplus electric power while the hull movement is stopped to drive the seventh hydraulic pump 73. Then, the pressure is increased by the seventh hydraulic pump 73 and supplied to the accumulator 80 to be used as regenerative energy.
Other configurations relating to the dredging machine M of FIGS. 14 and 15 are the same as those of the dredging machine M of FIGS. 1 to 13, and the description thereof will be omitted. In the figure, the same reference numerals as those in FIGS. 1 to 13 indicate the same or corresponding parts.

(2) Dredging Method Using Dredging Machine Next, a dredging method using the dredging machine M will be described.
In the dredging work, there is also a pump dredging method and the like, but the present invention is a grab dredging method using the dredging machine M. The earth and sand E deposited on the seabed is excavated by the grab bucket G. The bucket G suspended from the tip of the jib is moved up and down by the support drum 11 on the swivel body 91 capable of turning 360 degrees, and the earth and sand E on the seabed is dredged.
1 and 5 show the bucket unwinding process, and as shown in FIG. 4, the process proceeds from the bucket unwinding to the bucket hoisting including the bucket closing and ground cutting, turning, bucket opening, and turning. One cycle ends. This one cycle is repeated to perform the dredging work. In FIG. 4, the horizontal axis indicates the time axis, and the vertical axis indicates the uppermost bucket state, engine output, potential energy recovery hydraulic pump 51, support drum 11, opening / closing drum 21, swivel motor 93, and other equipment items. The figure shows how those device items change over time. In the support drum 11 and the opening / closing drum 21, a large amount of energy is generated in the hoisting process including the ground cutting, but the time zone when the consumption (energy consumption) of the bucket operation peaks is the ground cutting. During each process, the engine 61 is operated at a substantially constant rotation speed within a range of good fuel efficiency at the working rotation speed.

The dredging method using the dredging machine M is performed as follows, for example. In FIGS. 5 to 10, middle black arrows represent the operation of each device, and white arrows represent the flow of energy.
First, in the bucket unwinding step of FIG. 5, since the bucket G having a large mass drops by its own weight, all the energy of the engine 61 is hydraulically accumulated as shown in FIGS. 3 to 5. While the first and second clutches 19 and 29 are disconnected, the third clutch 39 is engaged and the surplus output recovery hydraulic pump 31 connected to the engine crankshaft 610 recovers all of the engine output. The recovered energy is sent to the accumulator 80 and stored there.
Further, when the bucket G is lowered by its own weight, the wire 15 is fed from the support drum 11 and the wire 25 is fed from the opening / closing drum 21 to rotate both drums 11 and 21. By the control means CR, the fifth clutch 59 connected to the rotating shaft 111 of the support drum 11 is fitted, and the potential energy recovery hydraulic pump 51 is started to generate the flood control. The generated oil pressure is sent to the accumulator 80 and accumulating as regenerative energy.

In the subsequent bucket closing step of FIG. 6, the bucket G is closed. In this embodiment, the second clutch 29 is engaged, and the drive shaft 611 of the torque converter 65 that transmits engine power rotates the open / close drum 21 via the transmission device 66 including the speed reducer, winds the wire 25, and winds the bucket G. close. The seabed sediment E is taken into the bucket G. The control means CR engages the second clutch 29 and disconnects the fifth clutch 59. The third clutch 39 is kept in the engaged state. The output obtained by subtracting the output used for the bucket closing operation from the high fuel efficiency output of the engine output is collected by the surplus output recovery hydraulic pump 31 and accumulated in the accumulator 80.
At this time, the discharge amount of the surplus output recovery hydraulic pump 31 is controlled by comprehensively determining the governor opening degree, the amount of pressure accumulated in the accumulator 80, the wire tension, the operation schedule, and the like by the control means CR. Specifically, the total output of the torque converter 65 output and the hydraulic accumulator output is controlled in the fuel efficiency efficiency output region (inner region of the ellipse in FIG. 11), which is about 80% of the engine output. Here, for 100% engine output, the output point of the highest fuel efficiency in the engine is 100%.
Since there is no engine output used for the bucket opening / closing operation in the bucket G to which the device for opening / closing using the electric motor is attached, the surplus output recovery hydraulic pump 31 recovers all of the engine output.

The ground cutting and bucket hoisting shown in FIG. 7 below are performed in the same operation. Ground cutting is the initial stage of the hoisting process. The first and second clutches 19, 29 are engaged, the engine 61 operates in the high fuel efficiency range, and the engine output is all supported by the support drum 11 and the opening / closing drum 21 via the torque converter 65 and the transmission device 66 including the reduction gear. Used for rotary motion. The third clutch 39 that connects the engine 61 and the surplus output recovery pump 31 is disconnected, and pressure is not accumulated in the accumulator 80.
Then, the fourth clutch 49 is engaged, and the assist motor 41 is driven by the energy accumulated in the bucket unwinding process, the bucket closing process, and the like to support the rotational movement of the support drum 11 by the engine 61. The control valve 84 is opened, the assist hydraulic motor 41 is driven by the hydraulic energy accumulated in the accumulator 80, the fourth clutch 49 is engaged, and the assist hydraulic motor 41 assists ground cutting and bucket hoisting. To do. In addition to the engine output, the assist motor 41 assists the rotational movement of the support drum 11, and the energy required for ground cutting and bucket hoisting is secured. Grab the earth and sand E on the seabed with the bucket G.

In the subsequent swivel step, the swivel hydraulic motor 93 is driven by the hydraulic energy accumulated by the accumulator 80 (FIGS. 3 and 8). The swivel body 91 is turned to move the bucket G suspended from the jib J on the dredging place to the soil carrier side. By the turning process, the bucket G that grabs the earth and sand E is carried to the upper position of the earth carrier that comes alongside.
The control means CR engages the third clutch 39, collects all the engine output by the surplus output recovery hydraulic pump 31, and accumulates the pressure in the accumulator 80. The first clutch 19, the second clutch 29, and the fourth clutch 49 are disengaged. Here, when the oil pressure of the accumulator 80 is insufficient, if the swivel hydraulic motor 93 is driven and swiveled by the surplus output recovery hydraulic pump 31, the swivel operation is more smoothly performed, which is preferable. Further, if the hydraulic pressure generated when the swivel body 91 is stopped to be swiveled is stored in the accumulator 80 as regenerative energy as shown by the broken line in FIG. 8, energy saving is further promoted, which is more preferable.

In the subsequent bucket opening step of FIG. 9, the wire 25 of the opening / closing drum 21 is extended to open the bucket G. Since the weight of the earth and sand E is added to the weight of the bucket shell and the bucket opening operation proceeds, the engine output is not used. With the third clutch 39 still engaged, the surplus output recovery hydraulic pump 31 connected to the crankshaft 610 recovers almost all of the engine output. The recovered energy is stored in the accumulator 80. The first clutch 19 is kept disengaged, but the second clutch 29 is engaged. When the bucket is opened, the opening / closing drum 21 is rotated by the wire 25, the fifth clutch 59 is engaged, and the clutch is transmitted to the potential energy recovery hydraulic pump 51 to store hydraulic pressure as regenerative energy.
In the bucket opening process, the bucket G carried on the earthen carrier is opened, and the earth and sand E is loaded on the earthen carrier.

The subsequent turning process is an operation of returning to the original pre-turning state (FIG. 10). The turning direction is only opposite to that of the turning process. The work and operation in that process are the same as in the turning process, and the description is omitted. When the final turning process is completed, one cycle is completed, and after that, this cycle is repeated to continue the dredging work. When the dredging work at that place is completed, the spud 72 is used by the hull side diesel generator 71, the dredging place is sequentially shifted, and the dredging work is performed at a new place, and finally the necessary dredging work is completed.

(3) Effect According to the dredging method using the dredging machine configured in this way, the surplus output energy of the engine 61 at low load is recovered and accumulated, and this is utilized for engine assist at high load to save energy. Can be planned. Until now, the surplus output of the engine 61 has not been used, and even if the hydraulic pump for hydraulic equipment such as the swivel motor 93 is constantly driven to generate flood control, the entire amount is driven by the relief valve except during swivel. It was abandoned. When the hydraulic energy was released to atmospheric pressure, it became heat energy to raise the oil temperature, and an oil cooler had to be used to lower the oil temperature. On the other hand, it is necessary to use an engine 61 having a large output in order to cope with the hoisting process including ground cutting, and there are problems of high equipment cost and increase in fuel consumption.
As in the present invention, the engine surplus output during processes other than the ground cutting and bucket hoisting processes is recovered and stored or stored, and this is used for the ground cutting and bucket hoisting processes that require a large amount of energy (assist). Then, since the high load region is cut, the engine 61 having a small maximum output can be selected. The engine 11 can be made compact, and the equipment cost of the dredging machine M can be reduced as compared with the conventional one.

Then, by accumulating or storing the output of the engine 61 when the work load is low, the engine 61 can always be used in the output range with good fuel efficiency. By averaging the engine output, the engine 61 can be used in the high fuel efficiency range. The running cost (fuel cost) can be suppressed as well as the initial cost (equipment cost). It is also effective in reducing greenhouse gases. Furthermore, the assist at the time of ground cutting eliminates the overload of the engine 61, suppresses the generation of air pollutants such as noise and black smoke due to the overload, and can also suppress the deterioration of fuel efficiency.

At present, the maximum of the Diesel engine-driven dredging machine M is 30m ^{class 3,} but this is the largest one currently used by the torque converter 65, and there is a fact that this is a bottleneck. .. According to the dredging method using this dredging machine , even larger dredging machines M and dredging vessels D can be constructed, which leads to an increase in dredging work capacity.

Further, if the surplus output recovery pump 31 is the surplus output recovery hydraulic pump 31 that converts the surplus output of the engine 61 into hydraulic energy and supplies it to the accumulator, and the assist motor 41 is the assist hydraulic motor 41, it is durable. It will be a dredging machine M that is even more excellent in terms of properties, safety, and cost. When using a generator, a storage battery, or an electric motor, there is a large loss in the power generation efficiency of the generator and the charge / discharge efficiency of the storage battery, the life of the secondary battery is short, and the cost burden is large. When a capacitor is used, there is a problem that it can be assisted only instantaneously due to the discharge characteristics, but when the hydraulic pump 31, the accumulator 80 or the hydraulic motor 41 is used, such a problem does not occur. There is no discharge when using hydraulic equipment, and unlike using electrical equipment, it is safe to use in the sea exposed to seawater, and each component equipment is excellent in stability and durability.

Furthermore, if the potential energy of the bucket is converted to flood control, recovered and stored, and used when cutting the ground or hoisting the bucket, which requires energy, it is possible to effectively utilize the energy converted to thermal energy by the frictional force of the brake and discarded. In addition to the recovery of the surplus output of the engine 61, the recovery of the bucket potential energy can be used in combination to continuously and reliably assist in the ground cutting and hoisting processes.
Furthermore, when the seventh hydraulic pump 73 is turned by the seventh electric motor 72 that has recovered the surplus electric power of the hull moving diesel generator 71, the hydraulic pressure can be supplied to the accumulator 80, and the regenerative energy is further increased. Assist in the cutting and hoisting processes can be performed stably and reliably. By organically relating the dredging machine Ziesel engine 61 and the hull moving Ziesel generator 71, which have been considered separately in the past, it is possible to achieve more effective energy saving.
As described above, the dredging method using the dredging machine of the present invention exerts many excellent effects described above and is extremely useful.

In the present invention, the present invention is not limited to the one shown in the above embodiment, and various modifications can be made within the scope of the present invention according to the purpose and application. The shape, size, number, etc. of the support drum 11, the opening / closing drum 21, the surplus output recovery pump 31, the assist motor 41, the potential energy recovery hydraulic pump 51, and the like can be appropriately selected according to the application. For example, in FIG. 3, the surplus output recovery pump 31 may be provided on one end side of the crankshaft 610 instead of the other end side. In FIG. 3, a power divider (power dividing mechanism) is provided in the middle of the drive shaft 611 connecting the torque converter 65 and the transmission device 66 including the speed reducer, and is connected to the rotating drum 11 and the surplus output is recovered through the power divider. It can also be connected to the pump 31. Further, in the embodiment, the surplus output energy of the engine 61 was recovered by the surplus output recovery pump 31 in all the operating time zones of the bucket unwinding, the bucket closing, the turning, the bucket opening, and the turning except at the time of hoisting. Of course, it does not have to be collected during all operating hours.

11 Support drum 15 Wire 19 1st clutch 21 Open / close drum 25 Wire 29 2nd clutch 31 Excess output recovery pump (surplus output recovery hydraulic pump)
39 Third clutch 41 Assist motor (Assist hydraulic motor)
49 4th clutch 51 Potential energy recovery hydraulic pump 59 5th clutch 61 Engine 610 Crankshaft 611 Drive shaft (engine drive shaft)
71 Hull movement diesel generator (hull side generator)
72 Seventh Electric Motor (Electric Motor for Recovering Surplus Power)
73 Seventh hydraulic pump (hydraulic pump for collecting surplus power)
79 7th clutch 80 accumulator 91 swivel body BT storage battery CR control means (controller)
D Dredger M Dredger G Grab bucket (bucket)
J jib
SP Hull movement spud (spud)

Claims (1)

Equipped on a dredger, a jib protruding from a swivel body, a wire is attached to the jib, a grab bucket is hung on the wire tip side, and the wire base end side is wound so that it can be hoisted and unwound. A support drum provided with a rotating drum portion and a crank shaft for rotating drive are connected to the support drum via a first clutch, and an engine for rotating the support drum is connected to the crank shaft via a third clutch. , The surplus output recovery generator that recovers the surplus output of the engine and supplies it to the storage battery, and the support drum connected to the support drum via the fourth clutch, and the energy stored in the storage battery is used to support the engine. Using an assist motor that supports the rotational movement of the drum, and a dredging machine equipped with
The assist motor supports the rotational movement of the support drum by the engine during the grab bucket hoisting process while the bucket hoisting, bucket closing, bucket hoisting, swiveling, bucket opening, and swirling processes are sequentially performed. On the other hand, during a process outside the hoisting process of the grab bucket, the surplus output energy of the engine is recovered by the surplus output recovery generator and stored in the storage battery.
Further, the engine is operated at a substantially constant output in a high efficiency range of fuel efficiency at the working rotation speed of the engine, and the surplus output energy of the engine is recovered by the surplus output recovery generator and the storage battery. In addition, the hull-side generator that activates the hull-moving spud is connected to the storage battery , and the spud is used by the hull-side generator to sequentially shift the dredging location to perform drenching work at a new location. A dredging method using a dredging machine, which comprises operating the hull-side generator even while the hull movement is stopped, recovering the surplus electric power, and supplying the surplus electric power to the storage battery.

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