JPH05493B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dredger, and particularly to a dredger that performs dredging work using a grab bucket.

[Prior Art] A dredger as shown in FIG. 14 is generally known as a dredger that uses a grab bucket as a dredging means.

This dredger uses a revolving crane type rope grab bucket for dredging. As shown in the figure, a base b is attached to the bow deck of a barge a, and a swing part d of a crane c is provided on the base b. A wire g is suspended from a pulley f provided at the tip of the boom e, and a grab bucket h is attached to the wire g.

There is also an example in which a construction machine, such as a backhoe, is used instead of the crane c. As shown in FIG. 15, a telescopic arm j is attached to the tip of a bucket hoe i, and a grab bucket h is provided at the lower end of this arm j.

[Problems to be Solved by the Invention] By the way, in a dredger using a swing crane, the area occupied by the swing section d of the crane is large, and the turning radius of the swing section d is also inevitably large.
Therefore, the overturning moment acting on the barge a becomes large, and the width and length of the barge a, that is, the barge a itself, becomes large in order to prevent the barge a from overturning. At the same time, manufacturing costs increase.

Furthermore, since the work is carried out by placing an earth and sand carrier (not shown) on the side of barge a, barge a has a large width, and a large space is required in the lateral direction relative to the forward direction of dredging work. I need. For this reason,
In narrow waterways such as rivers, dredging operations may be hindered, and other vessels may be unable to navigate during dredging operations. Furthermore, even when it is necessary to secure a waterway urgently, it is necessary to excavate a channel wider than necessary, which slows down the forward speed of dredging work. Furthermore, since the grab bucket h is only suspended by the rope g, there are problems such as the grab bucket h falling over or being insufficiently grasped due to irregularities on the bottom of the water, slopes, etc., resulting in a decrease in work efficiency.

In the case of a dredger using the backhoe i, the telescopic arm j is only mechanically extended and contracted by the operator, so the barge a may be damaged by waves, etc.
When the grab bucket is shaken, it may violently collide with the bottom of the water or rise suddenly when trying to grab dirt, etc. at the bottom of the water. For this reason, there was a problem that dredging work could not be carried out when barge a was shaking.

Furthermore, in general, dredging work involves stirring up the surrounding seawater, etc. along with the sediment from the bottom and riverbed each time it is excavated, causing problems such as damage to surrounding fishing grounds due to seawater pollution.

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to miniaturize the barge and place the earth and sand carrier at the stern of the barge so that it can enter narrow rivers and other waterways and be used for dredging in those waterways. work, and furthermore,
The forward speed of dredging can be increased in emergencies, etc., and a wide area can be efficiently dredged with one mooring without being affected by the movement of the barge, and at the same time, the spread of seawater pollution caused by dredging work can be prevented as much as possible. Our goal is to provide a dredger that can.

[Means for Solving the Problems and Their Effects] The first invention provides a hopper provided on a barge for receiving dredged earth and sand, and a hopper which can freely extend up and down into the dredging work area from the barge. The arm is suspended from the tip of the arm so that it can tilt forward, backward, left and right, and expand and contract vertically.It extends into the dredging work area and excavates the earth and sand, and expands and contracts to transport the dredged earth and sand to the above-mentioned hopper. The barge is equipped with a dredging machine section for loading the barge into the water, and the barge's center of gravity fluctuates less, making it possible to downsize the barge.

In addition to the configuration of the first invention, the second invention provides a structure in which the dredging machine is connected to drive means that control the tilting of the dredging machine part in the front, back, left, and right directions and the expansion and contraction in the vertical direction, and the dredging machine is moved by the movement of the barge. The barge is equipped with a vibration compensation device for absorbing external force transmitted to the dredging machine section, and an extension drive pressure adjustment device for adjusting the extension drive pressure of the drive means that controls the vertical expansion and contraction of the dredging machine section. This allows dredging to be carried out efficiently without being affected by any disturbances in the area.

Furthermore, in addition to the configuration of the first invention, a third invention includes a pollution diffusion control means that is detachably provided in the dredging machine part and covers the dredging part to control the spread of pollution generated during excavation. This system is designed to prevent the pollution that occurs during dredging from spreading into surrounding waters.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of the dredger, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a front view of the dredger.

As shown in the figure, on the deck of a barge 2 of a dredger 1, a luffing arm 3 is provided at the bow part of the barge 2 so that it can be raised and lowered freely, and its base end is pivotally supported by a support stand 5 on the deck side with a pin 4. ing. A gimbal 6 is pivotally supported at the tip of the arm 3 via a pin 7 so as to be tiltable in the longitudinal direction (longitudinal direction of the barge 2). and,
A dredging machine part 8 is suspended on this gimbal 6 via a pin 9 so as to be tiltable in the left-right direction (in the width direction of the barge 2).

This dredging machine section 8 is shown in enlarged views of main parts in FIGS. 4 and 5 and in a schematic view in FIG. 6.
A guide frame 10 is supported by a pin 9 on the gimbal 6 so as to be tiltable in the left-right direction, and an elevating cylinder 12 is suspended within the guide frame 10 by a pin 11 from its upper end. Further, near the lower end of a cylindrical telescopic arm 14 is fixed to the lower end of the rod 13 of the lifting cylinder 12.
In this state, the elevating cylinder 12 is inserted into the telescopic arm 14, and as the elevating cylinder 12 operates, the telescopic arm 14 surrounds the cylinder 12 and moves up and down. Inside the guide frames 15 and 16 located at the middle and lower ends of the guide frame 10, there is provided a structure for guiding the vertical movement of the telescoping arm 14 within the frame 10 and for supporting against external forces caused by excavation, etc. when the hull is rocking. Guide roller 17,1
8 is provided. These guide rollers 1
A plurality of 7 and 18 are provided so as to surround the telescopic arm 14 and equally support the outer periphery thereof. A hydraulic grab bucket 1 is attached to the lower end of the telescoping arm 14.
9 is pivotally supported by a pin 20 so as to be tiltable in left and right directions, and an opening/closing cylinder 21 for opening and closing the grab bucket 19 is connected to the pin 20 and the bucket 19.
It is provided by connecting parts.

A hydraulic cylinder 22 for tilting back and forth serves as a driving means for tilting the guide frame 10 supported by the gimbal 6 back and forth at the tip of the undulating arm 3.
is provided with one end being pivotally supported by the intermediate guide frame 15 of the guide frame 10 and the other end being pivotally supported by the undulating arm 3. Furthermore, a hydraulic cylinder 23 for left and right tilting as a driving means for tilting the guide frame 10 left and right is provided with one end being pivotally supported by the intermediate guide frame 15 and the other end being pivotally supported by the gin hull 6. Further, near the base end of the hoisting arm 3, there is a hoisting hydraulic cylinder 2 as a driving means for hoisting the arm 3.
4 is provided with one end being pivotally supported on the arm 3 and the other end being pivotally supported on the barge 2 side. Here, 25 to 30 are support pins for each hydraulic cylinder 22, 23, and 24.
Moreover, 31 is a stopper that supports the turning limit of the erecting arm 3 and prevents it from rolling backwards.

As a result of the above, the grab bucket 19 rises from the bottom floor S, such as the bottom of the water, by the expansion and contraction of the telescoping arm 14,
It is configured to move onto the barge 2 by raising the erecting arm 3.

On the other hand, an earth and sand dumping hopper 32 is fixed on the deck directly below the grab bucket 19 when the undulating arm 3 is raised to the stopper 31 position. A shipboard conveyor 33 for transporting earth and sand is located below the lower opening of the hopper 32.
The onboard conveyor 33 is provided extending from the lower part of the hopper 32 on the deck toward the rear of the stern, and is configured to drop earth and sand into an earth and sand carrier 34 moored at the stern of the barge 2. In addition, 35 is a rear drive pulley, 36 is a front head pulley, 3
7 is a carrier roller, 38 is a chute, and 39 is a support frame that supports the conveyor 33.

Further, on the deck of the barge 2, mooring winches 40a, 40b, 41a, and 41b for mooring the barge 2 are installed on both sides of the bow and both sides of the stern. 42a, 42b, 43a, 43b are anchors on the opposite shore or submarine anchors and mooring winches 40
It is a mooring rope that connects 40b, 41a, and 41b. Furthermore, on the deck, maneuvering winches 44a and 44b are installed on both sides for pulling the earth and sand carrier 34 toward the stern of the ship. A ship maneuvering winch 45a for shifting to
45b is provided at the stern end. 46a, 4
6b, 47a, and 47b are ropes for ship maneuvering.

In the hydraulic circuit of each cylinder 21, 22, 23, 24, as shown in FIG.
In order to absorb the impact transmitted to the hoisting arm 3 and the dredging machine part 8 when the grab bucket 19 collides with the bottom floor S or suddenly rises from the bottom floor S due to the oscillation of A sway compensator 48 is connected to each hydraulic circuit, and a hydraulic oil flow rate regulator 49, which is an extension drive pressure regulator, is further provided to adjust the ground pressure when the grab bucket 19 lands on the bottom S. It is being

The overall configuration of the hydraulic circuit is as follows.
A power pump 51 and a control pump 52 are connected to the hydraulic pump driving engine 50. The suction side of the power pump 51 communicates with an oil tank 53, and the discharge side communicates with a rod side 55 of the lifting cylinder 12 via a supply pipe 54. The head side 56 of the lifting cylinder 12 is a hydraulic tank 53.
is connected to. A pressure switch 57 is installed in the middle of the supply pipe 54 to detect the pressure inside this pipe 54.
and a relief valve 58 that prevents the inside of the pipe 54 from exceeding a predetermined pressure. Note that 59 is a check valve.

Further, a hydraulic oil flow rate adjustment device 49 is provided in connection with the supply pipe 54 . Specifically, a discharge pipe 60 that smoothly returns the return oil from the lifting cylinder 12 to the oil tank 53 and a flow rate adjustment pipe 61 that adjusts the flow rate of the return oil are connected to the supply pipe 54 in parallel with each other. There is. and,
The discharge pipe 60 and the flow rate adjustment pipe 61 communicate with the oil tank 53 via a check valve 62 in the middle thereof. The discharge pipe 60 is provided with a check valve 63 that opens and closes this pipe 60, and the flow rate adjustment pipe 61 is provided with a throttle valve 64 that adjusts the flow rate of hydraulic oil.
A check valve 65 for opening and closing this pipe 61 is provided.

The suction side of the control pump 52 is connected to the oil tank 53.
The discharge side communicates with two solenoid valves 67 and 68 arranged in parallel via piping 66, respectively. A pipe 66a on the side of the solenoid valve 67 communicates with a check valve 63 of the discharge pipe 60 to open and close this valve 63, and a pipe 66b on the side of the solenoid valve 68 communicates with a check valve 65 of the flow rate adjustment pipe 61. This valve 65 is then opened and closed. A relief valve 69 is connected to the pipe 66 to prevent the pressure inside the pipe 66 from exceeding a predetermined pressure.

The hydraulic oil flow rate adjustment device 49 is configured as described above.

Furthermore, a vibration compensator 48 is provided on the rod side 55 of the lifting cylinder 12.

Specifically, the rod side 55 of the lifting cylinder 12
The piping 70 connected to the solenoid valve 71
It communicates with the piston accumulator 72 via. This piston accumulator 72 is provided with a piston 73 that can freely move in the longitudinal direction.With this piston 73 as a boundary, hydraulic pressure is applied to the lifting cylinder side 74 and to the opposite side of the lifting cylinder side 74. is affected by air pressure. Furthermore, two air tanks 75 are connected to the pneumatic side of the piston accumulator 72. still,
These two air tanks 75 have a capacity such that a change in pressure with respect to a change in the piston 73 of the piston accumulator 72 can be ignored. In addition, solenoid switches 67, 68, 71
is electrically connected to the pressure switch 57.

The hydraulic circuit configured as described above is also installed in the luffing cylinder 24, the hydraulic cylinders 22 and 23 that tilt the guide frame 10 in the front, back, left, and right directions, and the opening/closing cylinder 21 of the grab bucket, and further includes two hydraulic circuits that tilt the guide frame 10. cylinder 2
2 and 23 are provided with safety valves (not shown) that operate only when the grab bucket 19 lands on the ground and operate at low pressure to prevent damage to the dredging machine section 8 due to the movement of the barge 2.

In addition, the above-mentioned undulation cylinder 24 and guide frame 1
A hydraulic adjustment mechanism (not shown) is provided between the guide frame 10 and the hydraulic cylinder 22 that tilts the guide frame 10 back and forth so that the guide frame 10 is always kept vertical when the hoisting arm 3 moves up and down.

Furthermore, as shown in FIGS. 10 to 13, the dredging machine section 8 includes a grab bucket 19 that is disposed at its lower end and performs dredging work on the bottom floor S. A contamination diffusion control means is removably provided to cover the dredged portion T to be dredged and to restrict the dispersion of contamination generated during excavation. First of all,
To briefly explain the structure of the grab bucket 19,
The grab bucket 19 includes an upper frame portion 110 supported by a pin 20 at the lower end of the telescoping arm 14 and connected to one end of an opening/closing cylinder 21, and a rotating bucket shell 111 to which the other end of the opening/closing cylinder 21 is connected and driven to open and close. a lower frame portion 105 that rotatably supports the movable base end via a pin 112;
The support bracket 106 is suspended between the lower frame part 105 and the upper frame part 110 to support the lower frame part 105 and the upper frame part 110. The pollution diffusion control means is configured to surround the bucket tossiel 111 that is driven to open and close to perform dredging work. In this example, the pollution diffusion control means are:
It is composed of a cover 100 that covers the entire bucket shell 111 and shields the dredged portion T of the bottom floor S from the surrounding water area. To explain this cover 100 specifically, this cover 100 is a bucket Toshiel 1
A pair of side plates 102 that cover the bucket tosiel 111 from the front and rear directions, and a cover plate 101 that covers the bucket tosiel 111 from above and from the left and right are joined between these side plates 102, and the lower side facing the dredged portion T is open. . Moreover, this cover 100 is formed in a size that can accommodate the entire bucket shell 111 in its maximum open state. And especially this cover 1
00 is formed at the depth at which the bucket tosiel 111 lands on the bottom S when it lands on the bottom S in an open state for dredging work, and separates the dredged portion T from the surrounding water area. configured to shield.

Note that in this cover 100, the side plate 102 is the adjustment plate 1.
04 to the lower frame part 105, and the cover plate 1
01 is the bolt 10 attached to the lower frame part 105.
7 and is adapted to be detachably attached to the grab bucket 19.

In the figure, 103 and 108 pass through the cover 100 and extend from the upper frame portion 110 to the lower frame portion 10.
5 is a guide hole through which the support bracket 106 and the opening/closing cylinder 21 are inserted.

Next, the operation of the embodiment will be described.

When the main dredger arrives at its destination, for example barge 2
The mooring ropes 42a and 42b at the bow of the ship are moored to bollards on the opposite shore, and the mooring ropes 43 at the stern are moored to bollards on the opposite shore.
The anchors (not shown) connected to the tips of the mooring winches 40a, 43b are separately thrown into the bottom floor S of the seabed etc. by an anchoring boat (not shown), etc., and the mooring winches 40a, 40
The barge 2 is moored by operating the terminals b, 41a, and 41b. Then, as shown in FIGS. 8 and 9, the ropes 46a and 46b for maneuvering are connected to the earth and sand carrier 34 being towed by a tugboat (not shown) or the like. Next, the ship handling winches 44a and 44b are operated to bring the earth carrier 34 alongside the stern of the barge 2.
At the same time, ropes 47a and 47b for maneuvering the soil transport vessel 34 in order to shift it in the transverse direction of the barge 2 are connected to the soil transport vessel 34 by crossing them. Incidentally, FIG. 9 shows a state in which the soil transport ship 34 is shifted by operating the ship maneuvering winches 45a and 45b.

Next, dredging work will begin. First, when not working,
As shown by the imaginary lines in the figures and FIG. 4, the dredging machine section 8 fixed on the barge 2 is dropped into the dredging work area.

The hoisting cylinder 24 is contracted and the hoisting arm 3 is brought down to the dredging work area. At this time, guide frame 10
is always held vertically by the hydraulic adjustment mechanism. Next, the opening/closing cylinder 21 of the grab bucket 19 is contracted to open the grab bucket 19.
Then, extend the lifting cylinder 12 and extend the telescopic arm 1.
The grab bucket 19 at the lower end of No. 4 is dropped into the dredging work area of the bottom floor S. The dropping speed of the grab bucket 19 to the bottom floor S is determined by the hydraulic oil flow rate adjusting device 4.
By operating the solenoid valves 67 and 68 of 9 and adjusting the throttle valve 64, the hardness can be freely controlled to a value that corresponds to the hardness of the bottom floor S. Next, the opening/closing cylinder 21
Bucket 1 extending and biting into the bottom part S
By closing 9, the earth and sand are grabbed and excavated.

If pollution prevention measures are required, please refer to Section 10.
As shown in Fig. 13, the grab bucket 19
Attach the cover 100 to the For dredging work with cover 100 installed, grab bucket 19
At the same time as the hippo 100 lands on the bottom floor S, the dredged portion T by the bucket tosiel 111 is cut off from the surrounding water area. In this state, Bucket Toshiel 1
11 to carry out excavation work, the work area by the bucket tosiel 111 is limited to the cover 100, and even if dirt is suspended or seawater is stirred in the dredged part T and pollution attempts to spread. , can be confined within the cover 100, and the dispersion of pollution into surrounding waters during work can be effectively regulated.

Next, the lifting cylinder 12 is contracted and the bucket 1 is
9 is pulled up, the undulating cylinder 24 is extended, and the undulating arm 3 is raised to move the bucket 19 onto the barge 2. At this time, bucket 19 is hoppa 32
The bucket 19 is opened by extending the opening/closing cylinder 2 position, and soil is dropped into the hopper 32. The earth and sand in the hopper 32 is carried to the stern by a conveyor 33 and is dropped into the earth carrier 34. The empty bucket 19 is dropped into the dredging area again, but the guide frame 10 is tilted back and forth and left and right by the two hydraulic cylinders 22 and 23, dredging a wide area with one mooring. Furthermore, even when the guide frame 10 tilts to the left and right, the bucket 19 supported by the pins 20 always bites vertically into the bottom floor S, thereby efficiently dredging.

In addition, when dropping the earth and sand onto the earth transport vessel 34 by the conveyor 33, the ship maneuvering winches 45a and 45b are operated so that the earth and sand to be dropped are not biased, and the earth transport vessel 34 is moved in the width direction of the barge 2. Shift to to evenly drop soil and sand.

The hydraulic circuit when the bucket 19 is raised and lowered operates as follows.

When the bucket 19 is raised, the control pump 52 is unloaded and the solenoid valves 67 and 68 are turned on.
Turn it off. As a result, the check valve 63,
65 is in the closed state. Furthermore, solenoid valve 7
Turn 1 off as well. Then, the power pump 51 is turned on-load, hydraulic oil is sent to the rod side 55 of the lifting cylinder 12 via the supply pipe 54, and the bucket 19 is raised.

When the bucket 19 is lowered, the power pump 51 is unloaded and the control pump 52 is turned on-load. Then, the solenoid valves 67, 6 are adjusted according to the descending speed of the bucket 19 and the ground pressure to the bottom floor S.
8 as appropriate and check valves 63 and 65.
Activate ON and OFF.

Further, the oscillation compensator 48 operates as follows.

When the barge 2 is shaken by waves or the like, the dredging machine section 8 is also shaken along with the barge 2.

If this movement is an up-and-down motion, the bucket 19 that has landed on the bottom floor S may float up or collide with the bottom floor S as the barge 2 moves up and down, and grab dirt. It may become impossible to do so.

For this reason, in the hydraulic circuit of the lifting cylinder 12, the pressure switch 57 first senses a change in the internal pressure of the supply pipe 54 that occurs when the bucket 19 lands on the bottom floor S. A signal from the pressure switch 57 that senses the change turns the solenoid valves 67 and 68 OFF, and the discharge pipe 60 and flow rate adjustment pipe 61 are closed. Next, the solenoid valve 71 is turned on, and the lifting cylinder 12 and the oscillation compensator 48 are communicated with each other.

When the barge 2 sinks downward, the lifting cylinder 12 contracts and the oil pressure on the rod side 55 decreases. As a result, the oil pressure inside the piston accumulator 72 also decreases. When this oil pressure decreases below the preset pressures in the two air tanks 75, the piston 73 is pushed by the air pressure and moves, reducing the oil pressure in the accumulator 72 and the oil pressure on the rod side 55 of the lifting cylinder 12. is maintained at the pressure in the air tank 75.

When the barge 2 floats upward, the lifting cylinder 1
2 is extended, and the oil pressure on the rod side 55 increases. As a result, the oil pressure inside the piston accumulator 72 also increases. When this oil pressure exceeds the pressure in the air tank 75, the piston 73 is pushed toward the air side,
The oil pressure drops to the pressure in the air tank 75.

As described above, the bucket 19 is always pressed against the bottom floor S with a constant pressure even when the barge 2 moves up and down, thereby efficiently performing dredging work.

In addition, in response to the movement of barge 2 back and forth and left and right,
Similarly to the above, the hydraulic cylinders 22 and 23 that tilt the guide frame 10 are each provided with a vibration compensator 4.
8 is provided. This causes the barge 2 to sway when the bucket 19 lands on the floor, causing the telescopic arm 14
Abnormal external force applied to the dredging machine section 8 is absorbed by the vibration compensator 48 to prevent damage to the dredging machine section 8. The pressure in the air tank 75 of the vibration compensator 48 connected to the hydraulic cylinders 22 and 23 is as follows:
It is set in consideration of the strength of the dredging machine section 8 in the horizontal direction. Further, the vibration compensator 48 connected to the hydraulic cylinders 22 and 23 is provided with a safety valve (not shown) to double prevent damage.

Then, the dredging machine section 8 is fixed on the barge 2 when the dredging work is completed, stopped, or not working.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) Since the dredging machine part is of a luffing arm type, the overturning moment acting on the barge is reduced and the barge can be made smaller. This can reduce the manufacturing cost of the dredger.

(2) Since the barge can be made smaller and the soil carrier is placed alongside the stern of the barge to load the soil, it is possible to move forward with a narrow dredging width, making it easier to enter narrow waterways such as rivers. Dredging work is now possible in the waterway, and in the event of an emergency such as river flooding, dredging can be carried out quickly to prevent disasters, and rescue and rescue operations can be carried out.
It is also effective in reconstruction.

(3) Since the hydraulic circuit of each cylinder is equipped with a vibration compensation device, dredging work can be carried out even on days with bad wave height and sea conditions, increasing the number of working days per year and improving dredging capacity. Furthermore, since the oscillation compensator absorbs abnormal forces acting on the dredging machine, there is no need to reinforce the dredging machine, and an increase in weight and cost can be suppressed.

(4) Since the dredging machine part can be tilted forward, backward, left, and right, it is possible to dredge a wide area with a single mooring, and it is also possible to reduce complicated, long-time, and manpower-intensive maneuvering work, which improves dredging work efficiency. improves.

(5) By equipping the dredging machine with pollution diffusion control means, it is possible to prevent seawater pollution due to the dispersion of earth and sand during dredging operations, and to suppress the occurrence of damage to surrounding fishing grounds.

(6) Therefore, the dredging cost per unit volume of dredged soil can be kept low.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the dredger of the present invention, Fig. 2 is a plan view of Fig. 1, Fig. 3 is a front view of Fig. 1, Figs. 4 and 5 are enlarged views of main parts, and Fig. 6 The figure is a schematic diagram of the main parts, Figure 7 is a system diagram showing the hydraulic circuit, Figures 8 and 9 are schematic diagrams showing the state of the earth and sand carrier alongside the barge, and Figure 10 is a diagram of the pollution diffusion control means. A side view showing an example, FIG. 11 is a plan view of FIG. 10, FIG. 12 is a side view of FIG. 10, FIG. 12A is a view in the direction of the X arrow, and FIG. , FIG. 13 is a side sectional view showing the state of dredging work, and FIGS. 14 and 15 are schematic views showing a conventional example. In the figure, 2 is a barge, 3 is a hoisting arm, 8 is a dredging machine part, 21 to 24 are cylinders serving as driving means, and 32
48 is a hopper, 48 is a vibration compensator, 49 is a hydraulic oil flow rate adjustment device which is an extension drive pressure adjustment device, and 100 is a cover which is a pollution diffusion control means.

Claims (1)

[Scope of Claims] 1. A hopper provided on a barge to receive dredged earth and sand, a undulating arm provided on the barge so as to be able to extend up and down into the dredging work area, and the tip of the arm. and a dredging machine section which is suspended from the hopper so as to be tiltable back and forth and from side to side and extendable in the vertical direction, and which extends into the dredging work area to excavate earth and sand and expands and contracts to feed the dredged earth and sand into the hopper. A dredger featuring: 2. A hopper installed on the barge to receive dredged earth and sand, a undulating arm installed on the barge so that it can be extended upwards and downwards into the dredging work area, and a tip of the arm that tilts forward, backward, left and right. A dredging machine part that is freely and vertically extended and contracted and extends into the dredging work area to excavate the earth and sand, and expands and contracts to feed the dredged earth and sand into the hopper, and a dredging machine part to the front, back, left and right of the dredging machine part. a vibration compensation device for absorbing the external force transmitted to the dredging machine section due to the motion of the barge, and a vibration compensation device for absorbing the external force transmitted to the dredging machine section due to the motion of the barge; A dredger characterized by being equipped with an extension drive pressure adjustment device for adjusting the extension drive pressure of a driving means that controls the dredger. 3. A hopper installed on the barge to receive dredged earth and sand, a undulating arm installed on the barge so that it can be extended upwards and downwards into the dredging work area, and a tip of the arm that tilts forward, backward, left and right. A dredging machine part that is freely suspended and expandable in the vertical direction and extends into the dredging work area to excavate earth and sand and expands and contracts to throw the dredged earth and sand into the hopper, and a dredging machine part that is detachably attached to the dredging machine part. A dredger is characterized in that it is equipped with a pollution diffusion control means that covers the dredged part and controls the spread of pollution generated during excavation.