Dredge device and seabed deposit drilling machine

Abstract

To efficiently recover excavated seabed resource by minimizing the amount of resources left behind.SOLUTION: A dredge device includes: a chamber formed a bottom opening facing the sea bottom and a front opening facing one of a first direction intersecting a vertical direction; a suction device having a suction port disposed in the chamber and sucking sand grave soil water in the chamber through the suction port; and an injection device that injects liquid toward the sea bottom in the chamber, the chamber has a top plate disposed to face each other at a position spaced apart in the vertical direction on the sea bottom; and a pair of side plates extending downward in the vertical direction from the top plate toward the sea bottom and disposed such that the distance therebetween decreases with increasing distance from the front opening, the injection device has a plurality of injection nozzles disposed spaced apart from each other in the first direction along each of the pair of side plates.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to dredging equipment and subsea deposit excavators. [Background technology]

[0002] Various seabed resources exist on the seabed, such as hydrothermal deposits, cobalt-rich crusts, manganese crusts, and methane hydrates. For example, cobalt-rich crusts are widely distributed in thin layers on the surface of the seabed. When mining such seabed resources, drilling machines similar to surface miners are used.

[0003] Such an excavator is equipped with a dredging device that removes the sand, gravel, soil, and water containing the ore dug up by the drum cutter. As an example of such a dredging device, as described in Patent Document 1, a structure is known that includes a chamber formed to open to the ground, a suction device that sucks the sand, gravel, soil, and water from a suction port in the chamber, and a nozzle that sprays liquid into the chamber. In the chamber of this dredging device, an excavation device is disposed that includes a rotating drum that is rotated in the chamber and a bit that is attached around the rotating drum. The sand, gravel, soil, and water that is blown up on the back side by the excavation device is sucked in by the suction device from the suction port in the chamber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7084763 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in excavation equipment such as a drum cutter equipped with a rotating drum around which a bit is fixed, the sand and gravel containing the excavated seabed resources are not only rolled up on the back side but also on the left and right sides of the drum cutter. Furthermore, on an uneven seabed surface, the sand and gravel may accumulate in the valleys, and it may not be possible to fully recover the resources. Therefore, there is a demand for a dredging device to efficiently recover the excavated seabed resources while minimizing the amount of material left behind.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a dredging device and a seabed mineral deposit excavation machine that can efficiently recover excavated seabed resources while minimizing the amount of resources left behind. [Means for solving the problem]

[0007] In order to solve the above problems, the dredging device of the present disclosure comprises a chamber that is movable in one direction of a first direction intersecting the vertical direction and has a bottom opening facing the seabed and a front opening facing one of the first directions, a suction device having an inlet arranged in the chamber and sucking in sand, gravel, soil and water in the chamber through the suction port, and an injection device that injects liquid toward the seabed in the chamber, wherein the chamber has a top plate arranged to face the seabed at a position spaced apart in the vertical direction, and a pair of side plates extending downward in the vertical direction from the top plate toward the seabed and arranged so that the spacing between them becomes smaller as they move away from the front opening, and the injection device has a plurality of injection nozzles arranged spaced apart from each other in the first direction along each of the pair of side plates.

[0008] In addition, the seabed deposit excavation machine of the present disclosure includes the dredging device, an excavation machine body arranged vertically above the chamber and capable of traveling in the first direction, and an excavation device arranged vertically below the excavation machine body and forward of the chamber in the traveling direction. Effect of the Invention

[0009] According to the dredging device and seabed deposit excavation machine disclosed herein, it is possible to efficiently recover excavated seabed resources while minimizing the amount of resources left behind. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional side view of a seabed deposit drilling machine according to a first embodiment of the present disclosure. FIG. [Diagram 2] FIG. 1 is a perspective view showing a dredging device according to a first embodiment of the present disclosure. [Diagram 3] A cross-sectional view showing a dredging device according to a second embodiment of the present disclosure from the rear. [Figure 4] FIG. 13 is a perspective view showing a dredging device according to a second embodiment of the present disclosure, with the chamber omitted. [Diagram 5] FIG. 11 is a perspective view showing a dredging device according to a modified example of the second embodiment of the present disclosure. [Figure 6] FIG. 11 is a side view showing a dredging device according to a third embodiment of the present disclosure. [Figure 7] FIG. 11 is a side view showing a dredging device according to a modified example of the third embodiment of the present disclosure. [Figure 8] FIG. 11 is a rear view showing a dredging device according to a modified example of the third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments for carrying out the dredging device 4 and the seabed deposit excavator 1 according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to only these embodiments.

[0012] First Embodiment (Subsea mineral deposit drilling machine) The seabed ore deposit excavator 1 is a machine that excavates seabed resources such as hydrothermal deposits, cobalt-rich crust, manganese crust, and methane hydrate. The seabed ore deposit excavator 1 of this embodiment excavates cobalt-rich crust that covers the surface layer (about 1 cm to 25 cm) of the seabed F. Therefore, the seabed ore deposit excavator 1 is operated underwater (particularly in the deep sea). As shown in FIG. 1, the seabed ore deposit excavator 1 includes an excavator main body 2, an excavation device 3, and a dredging device 4.

[0013] (Excavator body 2) The excavator body 2 has a crawler (not shown) and is capable of traveling on the seabed F. The excavator body 2 is capable of traveling in a first direction D1. The excavator body 2 is disposed above the excavation device 3 and the dredging device 4 in the vertical direction Dv.

[0014] In this embodiment, the direction of travel of the excavator body 2, which intersects with the vertical direction Dv (perpendicular in this embodiment), is referred to as the first direction D1. Furthermore, one side of the first direction D1, on which the excavator body 2 advances, is referred to as the forward side D1f. Moreover, the other side of the first direction D1, on which the excavator body 2 retreats opposite the forward side D1f, is referred to as the rearward side D1r. Moreover, the width direction of the dredging device 4, which intersects with the first direction D1 and the vertical direction Dv (perpendicular in this embodiment), is referred to as the second direction D2 (see FIG. 2). The first direction D1 and the second direction D2 may be directions that intersect with the vertical direction Dv but are not perpendicular to it, depending on the inclination of the seabed F on which the excavator body 2 is traveling.

[0015] (Drilling Rig 3) The excavation device 3 excavates the surface layer of the seabed F. The excavation device 3 rolls up the gravel generated after excavation on both sides of the rear D1r in the first direction D1 and the second direction D2 relative to the excavation device 3. The excavation device 3 is disposed on the front D1f in the first direction D1 relative to the dredging device 4. In other words, the excavation device 3 is disposed outside the dredging device 4 and independent of the dredging device 4. The excavation device 3 is fixed downward in the vertical direction Dv relative to the excavator body 2. The excavation device 3 of this embodiment includes a rotating drum 31 and a bit 32.

[0016] The rotating drum 31 is driven to rotate about an axis O. The rotating drum 31 is formed in a cylindrical shape centered on the axis O. The rotating drum 31 can be rotated by a motor in either a clockwise or counterclockwise direction about the axis O. In other words, the rotating drum 31 can excavate the surface layer of the seabed F regardless of the direction of rotation.

[0017] A plurality of bits 32 are attached to the periphery of the rotating drum 31. The bits 32 are arranged so as to protrude outward from the outer circumferential surface of the rotating drum 31.

[0018] (Dredging Equipment) The dredging device 4 excavates the surface layer of the seabed F while moving over the seabed F with the excavator body 2, and collects the gravel soil produced after excavation together with seawater. The dredging device 4 transports the collected gravel soil to an offshore work ship (not shown) or platform (not shown). The dredging device 4 of this embodiment is fixed downward in the vertical direction Dv of the excavator body 2. The dredging device 4 is fixed downward in the vertical direction Dv relative to the excavator body 2. The dredging device 4 is fixed rearward D1r in the first direction D1 relative to the excavation device 3. The excavation device 3 of this embodiment includes a chamber 5, a suction device 6, and an injection device 7.

[0019] The chamber 5 is movable forward D1f in the first direction D1 by moving together with the excavator body 2. The chamber 5 has a hollow structure with a space S formed therein. The chamber 5 is formed with a bottom opening 50 facing the seabed F and a front opening 51 facing the front D1f in the first direction D1. Therefore, the interior of the chamber 5 faces the seabed F and is connected to the underwater in the front D1f of the first direction D1. As shown in FIGS. 1 and 2, the chamber 5 of this embodiment has a top plate 55, a pair of side plates 56, a rear plate 57, and a curtain portion 59.

[0020] The top plate 55 is disposed at a position spaced apart from the seabed F in the vertical direction Dv. The top plate 55 is disposed so as to face the seabed F. The top plate 55 is a plate-shaped member that extends horizontally to the seabed F. Therefore, the widest surface of the top plate 55 faces the vertical direction Dv. The top plate 55 is made of a metal material.

[0021] The pair of side plates 56 extend downward in the vertical direction Dv from the top plate 55 toward the seabed F. The pair of side plates 56 are arranged such that the distance between them decreases in the first direction D1 as they move away from the front opening 51. In this embodiment, the pair of side plates 56 are arranged spaced apart from each other in the second direction D2. Therefore, the pair of side plates 56 are furthest from each other in the first direction D1 at the position of the front opening 51.

[0022] The rear plate 57 extends downward in the vertical direction Dv from the top plate 55 toward the seabed F. The rear plate 57 connects the pair of side plates 56 to each other. That is, the pair of side plates 56 are closest to each other at the positions where the side plates 56 are connected to the rear plate 57 in the first direction D1.

[0023] In this embodiment, each of the side plates 56 and the rear plate 57 has a plate body 581 and a cover portion 582.

[0024] The plate body 581 is connected to the top plate 55. The plate body 581 extends downward in the vertical direction Dv from the edge of the top plate 55. The plate body 581 is made of the same metal material as the top plate 55. The plate body 581 is disposed at a position spaced apart from the seabed F in the vertical direction Dv.

[0025] The cover portion 582 is connected to the plate body 581 below in the vertical direction Dv. The cover portion 582 extends from the lower end of the plate body 581 in the vertical direction Dv toward the seabed F. The cover portion 582 is formed of a material or structure softer than the plate body 581. The cover portion 582 is configured, for example, as a soft material, not a metallic material but an elastic material such as rubber. Also, the cover portion 582 is formed, for example, as a soft structure, in a brush shape rather than a plate shape. The cover portion 582 is capable of coming into contact with the seabed F.

[0026] The curtain portion 59 is disposed so as to cover a part of the front opening 51. The curtain portion 59 is connected to the top plate 55. The curtain portion 59 extends downward in the vertical direction Dv from the edge of the top plate 55 in the first direction D1. The curtain portion 59 is formed to have a length approximately equal to that of the top plate 55 in the second direction D2. The curtain portion 59 is formed to have a length approximately equal to that of the plate portion in the vertical direction Dv. The curtain portion 59 is disposed at a position spaced apart in the vertical direction Dv from the seabed F. That is, when viewed from the first direction D1, the curtain portion 59 overlaps with the upper part of the front opening 51 in the vertical direction Dv, but does not overlap with the lower part of the front opening 51 in the vertical direction Dv. The curtain portion 59 is formed of a material or structure softer than the cover portion 582.

[0027] A space S is formed inside the chamber 5 by the top plate 55, the pair of side plates 56, the rear plate 57, and the curtain portion 59 as described above. In addition, a front opening 51 is formed by the top plate 55 and the pair of side plates 56 at a position facing forward D1f in the first direction D1 in the chamber 5. In addition, a bottom opening 50 is formed by the pair of side plates 56 and the rear plate 57 at a position facing downward in the vertical direction Dv in the chamber 5.

[0028] The suction device 6 sucks up the gravel, soil, and water in the chamber 5. The gravel, soil, and water is a mixture of gravel and soil that has been excavated from the surface layer of the seabed F by the excavation device 3 and stirred up, and seawater around the excavation device 3. The suction device 6 is capable of adjusting the flow rate of the gravel, soil, and water that it sucks up from the chamber 5. The suction device 6 in this embodiment has a suction port 61 and a transfer pipe 62.

[0029] The suction port 61 is disposed within the chamber 5. In this embodiment, the suction port 61 is an opening at the end of the transfer tube 62. The suction port 61 is disposed within the chamber 5 at a position protruding downward in the vertical direction Dv with respect to the top plate 55.

[0030] The transfer pipe 62 extends from the chamber 5 to a work boat or the like (not shown). The transfer pipe 62 in this embodiment is a hollow transport pipe. The transfer pipe 62 sucks up gravel, soil, and water via a pump (not shown).

[0031] The jetting device 7 jets high-pressure seawater (liquid) towards the seabed F within the chamber 5. The jetting device 7 takes in seawater from outside the chamber 5 and jets it as high-pressure seawater. The jetting device 7 jets high-pressure water with a higher pressure than the gravel and soil water within the chamber 5 towards the seabed F. The jetting device 7 jets high-pressure water so as to guide the gravel and soil deposited on the seabed F to the suction port 61 while causing it to float from the seabed F within the chamber 5. The jetting device 7 of this embodiment has a plurality of jet nozzles 71, a jet line 72, and a jet pump 73.

[0032] The multiple jet nozzles 71 are arranged apart from each other in the first direction D1 along the pair of side plates 56. The multiple jet nozzles 71 are arranged between the suction port 61 and the side plate 56 in the second direction D2 when viewed from the vertical direction Dv. The multiple jet nozzles 71 are arranged on both sides of the suction port 61 in the second direction D2 when viewed from above in the vertical direction Dv. In addition, at least one jet nozzle 71 is arranged on the rear D1r of the first direction D1 with respect to the suction port 61 when viewed from the vertical direction Dv. That is, the jet nozzle 71 is also arranged between the suction port 61 and the rear plate 57 in the first direction D1 when viewed from the vertical direction Dv. Therefore, the multiple jet nozzles 71 are arranged to surround the suction port 61 from the sides other than the front D1f of the first direction D1 when viewed from the vertical direction Dv. Adjacent jet nozzles 71 are arranged at equal intervals. The multiple jet nozzles 71 jet seawater straight in the vertical direction Dv toward the seabed F. The multiple jet nozzles 71 are arranged so as to penetrate the top plate 55 in the vertical direction Dv. The multiple jet nozzles 71 are fixed to the top plate 55.

[0033] The jet line 72 is capable of supplying seawater to the multiple jet nozzles 71. The jet line 72 is in communication with the multiple jet nozzles 71. The jet line 72 extends in the vertical direction Dv, then bends and extends along the top plate 55. The jet line 72 is a transport pipe having a smaller diameter than the transfer pipe 62. In this embodiment, as shown in FIG. 2, the jet line 72 has a first jet line 721 and a second jet line 722.

[0034] The first jet line 721 is connected to a plurality of jet nozzles 71 on one side in the second direction D2 across the suction port 61 when viewed from above in the vertical direction Dv.

[0035] When viewed from above in the vertical direction Dv, the second jet line 722 is connected to a plurality of jet nozzles 71 on the other side of the second direction D2 across the suction port 61. In other words, the second jet line 722 is connected to a plurality of jet nozzles 71 that are not connected to the first jet line 721. The second jet line 722 is a transport pipe having the same diameter as the first jet line 721.

[0036] As shown in Fig. 1, the jet pump 73 takes in seawater outside the chamber 5 as a liquid, increases the pressure, and supplies it to the jet line 72. The jet pump 73 is attached to the jet line 72 outside the chamber 5. The jet pump 73 sucks in seawater around the dredging device 4 through a filter (not shown). The high-pressure seawater discharged from the jet pump 73 is supplied to the first jet line 721 and the second jet line 722 with the flow rate being evenly distributed.

[0037] (Action and effect) The dredging device 4 and the seabed ore deposit excavator 1 configured as above have a chamber 5 in which a bottom opening 50 facing the seabed F and a front opening 51 facing the front D1f of the first direction D1 are formed. Therefore, the gravel excavated by the excavation device 3 is collected into the chamber 5 from the front opening 51 and the bottom opening 50 as the excavator body 2 moves forward D1f in the first direction D1. Furthermore, the gravel collected in the chamber 5 is rolled up by seawater sprayed toward the seabed F from the multiple jet nozzles 71. In particular, the gravel collected on the seabed F having an uneven shape such as a depression is also rolled up, and it is possible to prevent the gravel collected on the seabed F from being unable to be collected. At that time, the multiple jet nozzles 71 are arranged along the pair of side plates 56. Therefore, the gravel collected by the multiple jet nozzles 71 comes into contact with the side plates 56 and tends to gather near the center of the chamber 5. In this state, by sucking the gravel, soil, and water in the chamber 5 from the suction port 61, it is possible to reduce the amount of gravel and soil left behind in the chamber 5. Therefore, it is possible to efficiently recover the excavated seabed resources by reducing the amount of the excavated seabed resources left behind.

[0038] Furthermore, when viewed from the vertical direction Dv, the chamber 5 is formed such that the position of the front opening 51 in the first direction D1 is the widest in the second direction D2. That is, the chamber 5 is widest at the front opening 51 in the second direction D2. Therefore, gravel and soil can be efficiently collected into the chamber 5 from the front opening 51.

[0039] Moreover, the multiple injection nozzles 71 are disposed between the suction port 61 and the side plate 56 in the second direction D2 when viewed from the vertical direction Dv. Therefore, the gravel soil stirred up by the multiple injection nozzles 71 is more likely to come into contact with the side plate 56 on the outer side of the injection nozzles 71, and approaches the suction port 61 on the inner side. Furthermore, the gravel soil that comes into contact with the side plate 56 bounces back and approaches the suction port 61 on the inner side. In other words, the gravel soil stirred up by the multiple injection nozzles 71 is more likely to gather near the suction port 61 of the chamber 5 without being dispersed within the chamber 5. Therefore, the gravel soil collected in the chamber 5 can be sucked up with a smaller amount of the gravel soil left behind.

[0040] Moreover, the side plate 56 and the rear plate 57 have a plate body 581 connected to the top plate 55, and a cover part 582 connected below the plate body 581 in the vertical direction Dv. Furthermore, the cover part 582 is formed of an elastic material such as rubber or in a brush shape, and is made of a material or structure softer than the plate body 581. Therefore, the plate body 581 can ensure the strength of the side plate 56 and the rear plate 57. In addition, since the cover part 582, which is likely to come into contact with the seabed F, is made of a soft material or structure, even if the side plate 56 and the rear plate 57 come into contact with the seabed F, they can cover the seabed F while deforming to follow the shape of the seabed F. In other words, the cover part 582 can be deformed to pass through the seabed F having an uneven shape such as a large hump or large ore in the gravel soil while ensuring the airtightness of the chamber 5. Therefore, damage to the side plate 56 and the rear plate 57 can be suppressed while maintaining the efficiency of collecting gravel soil into the chamber 5.

[0041] Moreover, in the jet device 7, seawater taken in from outside the chamber 5 by the jet pump 73 is jetted from the multiple jet nozzles 71. Therefore, there is no need to separately prepare a liquid to be jetted in the chamber 5.

[0042] Second Embodiment Next, a second embodiment of the dredging device 4A according to the present disclosure will be described. In the second embodiment described below, the same reference numerals are given to the components common to the first embodiment, and the description thereof will be omitted. In the second embodiment, the dredging device 4A is different from the first embodiment in that a swirling component is imparted to the gravel, soil, and water sucked from the suction port 61A.

[0043] As shown in Figures 3 and 4, the dredging equipment 4A of the second embodiment further includes a swirling flow promoting section 8. The swirling flow promoting section 8 imparts a swirling component to the gravel, soil, and water sucked into the suction port 61A in the chamber 5. The swirling flow promoting section 8 imparts a swirling component along the inner circumferential surface of the transfer pipe 62 to the gravel, soil, and water flowing into the transfer pipe 62. The swirling flow promoting section 8 of this embodiment has an enlarged diameter section 81 and a swirling blade section 82.

[0044] The enlarged diameter portion 81 is formed so as to enlarge the suction port 61A in the chamber 5. The enlarged diameter portion 81 is formed so as to gradually narrow from the bottom to the top in the vertical direction Dv. The enlarged diameter portion 81 is formed in a cone shape with the lower end in the vertical direction Dv being the widest and the upper end in the vertical direction Dv being the narrowest, like an inverted funnel. The lower end of the enlarged diameter portion 81 in the vertical direction Dv opens in the chamber 5. Therefore, in the second embodiment, the opening at the lower end of the enlarged diameter portion 81 in the vertical direction Dv constitutes the suction port 61A. The upper end of the enlarged diameter portion 81 in the vertical direction Dv is connected to the transfer pipe 62. The enlarged diameter portion 81 is arranged so that the central axis of the transfer pipe 62 and the central axis O8 of the enlarged diameter portion 81 overlap with each other.

[0045] The swirl vane section 82 is disposed in the expanded diameter section 81. The swirl vane section 82 generates a vortex flow centered on the central axis O8 of the expanded diameter section 81 from inside the chamber 5 toward the transfer pipe 62. The swirl vane section 82 of this embodiment has a vane base 821 and a plurality of vane bodies 822. The vane base 821 is formed in a cone shape centered on the central axis O8 of the expanded diameter section 81.

[0046] A plurality of wing bodies 822 extend from the wing base 821. The plurality of wing bodies 822 extend from a surface of the wing base 821 facing upward in the vertical direction Dv along which the central axis O8 of the enlarged diameter portion 81 extends. The plurality of wing bodies 822 are arranged at intervals in the circumferential direction around the central axis O8 of the enlarged diameter portion 81. The wing body 822 connects the wing base 821 and the enlarged diameter portion 81. The wing body 822 is fixed to the wing base 821 and the enlarged diameter portion 81 in an immovable state. The wing body 822 has a curved wing surface that twists from the bottom to the top in the vertical direction Dv.

[0047] In the dredging device 4A of the second embodiment, the jetting device 7A further includes a plurality of enlarged diameter section jet nozzles 76A and an enlarged diameter section jet line 77A.

[0048] The multiple enlarged diameter section jet nozzles 76A are arranged independently of the multiple jet nozzles 71. The multiple enlarged diameter section jet nozzles 76A are arranged in an annular shape along the edge of the lower end of the enlarged diameter section 81 in the vertical direction Dv. Therefore, the multiple enlarged diameter section jet nozzles 76A are arranged so as to surround the enlarged diameter section 81 when viewed from the vertical direction Dv. Adjacent enlarged diameter section jet nozzles 76A are arranged at equal intervals. The multiple enlarged diameter section jet nozzles 76A jet seawater straight in the vertical direction Dv toward the seabed F. The multiple enlarged diameter section jet nozzles 76A are fixed to the enlarged diameter section jet line 77A.

[0049] The enlarged diameter section jet line 77A is capable of supplying seawater to the multiple enlarged diameter section jet nozzles 76A. The enlarged diameter section jet line 77A branches off from the jet line 72. When viewed from the vertical direction Dv, the enlarged diameter section jet line 77A extends in a ring shape along the edge of the lower end of the enlarged diameter section 81 in the vertical direction Dv. The enlarged diameter section jet line 77A is a transport pipe with approximately the same diameter as the jet line 72.

[0050] In the dredging device 4A of the second embodiment, a swirling component is imparted to the gravel, soil, and water sucked from the suction port 61A in the chamber 5. Specifically, the gravel, soil, and water pass between the blade bodies 822 in the enlarged diameter section 81, and the blade bodies 822 cause the gravel, soil, and water to swirl like a vortex. Therefore, while the gravel, soil, and water are sucked from the suction port 61A, a swirling flow is generated around the enlarged diameter section 81. As a result, the gravel and soil is more likely to be stirred up in the surrounding area including the lower part of the enlarged diameter section 81. Therefore, the gravel and soil is prevented from being left behind on the seabed F, and the gravel and soil collected in the chamber 5 can be reduced and sucked up. Therefore, the amount of the excavated seabed resources left behind can be reduced, and more efficient recovery can be achieved.

[0051] Additionally, multiple enlarged diameter portion jet nozzles 76A are disposed around the enlarged diameter portion 81. The seawater jetted toward the seabed F by the multiple enlarged diameter portion jet nozzles 76A scoops up the gravel and soil. This makes it even easier for the gravel and soil to be scooped up around the enlarged diameter portion 81. This prevents the gravel and soil from accumulating on the seabed F, and allows the gravel and soil recovered in the chamber 5 to be sucked up with less of it being left behind.

[0052] <Modification of the second embodiment> The swirl promotion section may have any configuration as long as it can impart a swirling component to the gravel, soil, and water sucked from the suction port 61B. For example, as a modification of the second embodiment, the swirl flow promotion section 8B may have a shape different from that of the second embodiment.

[0053] As shown in Fig. 5, the expanded diameter portion 81B of the modified example of the second embodiment is formed in a truncated cone shape such that the cross section is a trapezoid. The lower end of the expanded diameter portion 81B in the vertical direction Dv opens in the chamber 5. Therefore, the opening at the lower end of the expanded diameter portion 81B in the vertical direction Dv constitutes the suction port 61B. The upper end of the expanded diameter portion 81B in the vertical direction Dv is closed. The expanded diameter portion 81B is connected to the transfer pipe 62 in an upper region in the extension direction on the side surface.

[0054] Moreover, the swirl vane section 82B of the modified example of the second embodiment generates a vortex flow centered on the central axis O8 of the enlarged diameter section 81B from inside the chamber 5 toward the transfer pipe 62 by only one vane body 822B. The swirl vane section 82B has a vane base 821B and only one vane body 822B.

[0055] The blade base 821B is formed in a truncated cone shape centered on the central axis O8 of the expanded diameter portion 81B. The upper surface of the blade base 821B in the vertical direction Dv is connected to the expanded diameter portion 81B.

[0056] The wing body 822B is formed to protrude from the side of the wing base 821B in a flat plate shape. The wing body 822B extends in a spiral shape in the vertical direction Dv along the side of the wing base 821B. In other words, one wing body 822B is formed to be twisted from below to above in the vertical direction Dv. The wing body 822B is fixed to the wing base 821B and the enlarged diameter portion 81B in an immovable state.

[0057] The swirl flow promoting section 8B further includes a swirl nozzle 84 and a swirl nozzle line 85. The swirl nozzle 84 imparts a swirl component to the gravel, soil and water sucked from the suction port 61B in the chamber 5 by seawater. The swirl nozzle 84 injects high-pressure seawater. The multiple swirl nozzles 84 are arranged independently of the multiple jet nozzles 71 and the expanded diameter section jet nozzle 76A. The multiple swirl nozzles 84 are arranged in a ring shape apart from each other along the edge of the lower end of the expanded diameter section 81B in the vertical direction Dv. Therefore, the multiple swirl nozzles 84 are arranged so as to surround the expanded diameter section 81B when viewed from the vertical direction Dv. In other words, the multiple swirl nozzles 84 are arranged in parallel with the multiple expanded diameter section jet nozzles 76A when viewed from above in the vertical direction Dv. The multiple adjacent swirl nozzles 84 are arranged at equal intervals. The multiple swirl nozzles 84 spray seawater obliquely upward along a spiral flow path formed in the expanded diameter section 81B by the blade main body 822B from below to above in the vertical direction Dv. The multiple swirl nozzles 84 are fixed to a swirl nozzle line 85.

[0058] The swirl nozzle line 85 is capable of supplying seawater to the multiple swirl nozzles 84. The swirl nozzle line 85 branches off from the jet line 72. When viewed from the vertical direction Dv, the swirl nozzle line 85 extends in an annular shape so as to follow the edge of the lower end of the expanded diameter portion 81B in the vertical direction Dv. In other words, when viewed from above in the vertical direction Dv, the swirl nozzle line 85 is formed in an annular shape so as to be parallel to the multiple expanded diameter portion jet lines 77A. The swirl nozzle line 85 is a transport pipe having a diameter approximately the same as that of the jet line 72.

[0059] With this configuration, the same effect as in the second embodiment can be obtained. In addition, the modified example has a swirl nozzle 84 and a swirl nozzle line 85. Specifically, around the enlarged diameter portion 81B, high-pressure seawater is sprayed obliquely upward by the swirl nozzle 84. Therefore, the swirling flow generated around the enlarged diameter portion 81B becomes stronger. As a result, the strong swirling flow makes it easier for the gravel soil to be stirred up. Therefore, it is possible to further prevent the gravel soil from remaining on the seabed F, and the amount of gravel soil collected in the chamber 5 left behind can be reduced and sucked up.

[0060] <Third embodiment> Next, a dredging device 4C of a third embodiment according to the present disclosure will be described. In the third embodiment described below, the same reference numerals are given to the components common to the first and second embodiments, and the description thereof will be omitted. In the third embodiment, the dredging device 4C is different in that it is capable of following the uneven shape of the seabed F, which is not horizontal but has bumps.

[0061] 6, the dredging device 4C of the third embodiment is configured to allow the chamber 5 to follow the unevenness of the seabed F. Specifically, the dredging device 4C further includes an inclined traveling unit 91, a biasing mechanism 92, and a towing unit 93.

[0062] The inclined running section 91 is fixed to the chamber 5 in an immovable state. The inclined running section 91 is movable so as to incline with respect to an imaginary plane perpendicular to the vertical direction Dv while being in contact with the seabed F. Therefore, the inclined running section 91 is movable so as to incline at any angle while supporting the chamber 5 while being in contact with the seabed F. The inclined running section 91 of this embodiment has a frame portion 911 and a contact portion 912.

[0063] The frame portion 911 is fixed to the side plate 56 of the chamber 5 in an immovable state. A pair of frame portions 911 are arranged to sandwich the chamber 5 in the second direction D2. The frame portions 911 are formed of a material that is not deformed by the biasing force of the biasing mechanism 92. The frame portions 911 are arranged at a position spaced apart from the seabed F in the vertical direction Dv. The frame portions 911 may have a structure such as a frame body formed of multiple steel materials surrounding the chamber 5.

[0064] The contact portion 912 is movable while in contact with the seabed F. In this embodiment, the contact portion 912 is a plurality of tires that rotate relative to the frame portion 911. Therefore, the contact portion 912 rotates while in contact with the seabed F, thereby moving the chamber 5 along the seabed F via the frame portion 911. Note that the contact portion 912 may have another configuration as long as it is movable while in contact with the seabed F. For example, the contact portion 912 may be a sled-shaped member that can come into contact with the seabed F.

[0065] The biasing mechanism 92 biases the inclined traveling section 91 downward in the vertical direction Dv. The biasing mechanism 92 biases the inclined traveling section 91 against the excavator body 2 so as to press the inclined traveling section 91 against the seabed F. The biasing mechanism 92 damps the impact of the seabed F on the inclined traveling section 91 in the vertical direction Dv so as to reduce the impact. The biasing mechanism 92 of this embodiment has a plurality of suspensions 921. Each suspension 921 has, for example, a coil spring and a shock absorber. Each suspension 921 is connected to the frame section 911 and the excavator body 2. The plurality of suspensions 921 are arranged at intervals in the first direction D1 and the second direction D2. Therefore, the plurality of suspensions 921 bias the inclined traveling section 91 at four different points.

[0066] The towing unit 93 moves the inclined traveling unit 91 in the first direction D1 in association with the movement of the excavator body 2. The towing unit 93 is connected to the excavator body 2 and the frame unit 911 so as to be rotatable.

[0067] In this embodiment, a portion of the transfer pipe 62 has a flexible tube 65 that is highly flexible and can be bent in any direction. The flexible tube 65 is disposed below the excavator body 2 in the vertical direction Dv. The flexible tube 65 has, for example, a bellows structure.

[0068] According to such a dredging device 4C, the inclined traveling section 91 is supported on the excavator body 2 via a plurality of suspensions 921. That is, the inclined traveling section 91 is connected to the excavator body 2 in a state in which it can swing freely in the vertical direction Dv with respect to the excavator body 2 by the plurality of suspensions 921. Therefore, even if the seabed F is not horizontal but inclined, due to the uneven shape, the frame section 911 is kept in a state of being biased toward the seabed F while swinging by the plurality of suspensions 921 via the contact section 912 in contact with the seabed F. Therefore, the chamber 5 fixed to the frame section 911 of the inclined traveling section 91 can be kept in a position parallel to the seabed F. This makes it possible to keep the chamber 5 positioned in a stable position relative to the seabed F regardless of the uneven shape of the seabed F.

[0069] <Modification of the third embodiment> The inclined traveling section and the biasing mechanism may have any configuration as long as they can cause the chamber 5 to follow the uneven shape of the seabed F. For example, as a modification of the third embodiment, the inclined traveling section 91D and the biasing mechanism 92D may have shapes different from those in the third embodiment.

[0070] As shown in Figures 7 and 8, a dredging device 4D according to a modified example of the third embodiment further includes an inclined traveling section 91D and an urging mechanism 92D. The inclined traveling section 91D and the urging mechanism 92D according to this modified example are arranged as a pair independently with respect to the chamber 5. The inclined traveling section 91D and the urging mechanism 92D are arranged as a pair so as to sandwich the chamber 5 in the second direction D2. The inclined traveling section 91D and the urging mechanism 92D are independently movable on one side of the second direction D2 so as to make the chamber 5 follow the uneven shape of the seabed F.

[0071] The pair of inclined traveling sections 91D independently support the chamber 5 with respect to the excavator body 2. The inclined traveling section 91D of this modification has a support section 915, an arm section 916, a support fixing section 917, and a contact section 912D.

[0072] The support portion 915 supports the contact portion 912D rotatably about a virtual axis extending in the second direction D2.

[0073] The arm portion 916 extends from the excavator body 2 in a first direction D1. The arm portion 916 moves the support portion 915 in the first direction D1 in conjunction with the movement of the excavator body 2. The base end of the arm portion 916 is connected to the excavator body 2 rotatably around an imaginary axis extending in the second direction D2. The base end of the arm portion 916 is located forward D1f with respect to the chamber 5 in the first direction D1. The tip of the arm portion 916 supports the support portion 915 rotatably around an imaginary axis extending in the second direction D2. The tip of the arm portion 916 is located rearward D1r with respect to the chamber 5 in the first direction D1.

[0074] The support fixing part 917 connects the support part 915 and the chamber 5. The support fixing part 917 supports the chamber 5 in a movable state so that the chamber 5 is tilted in the second direction D2 relative to the support part 915 when viewed from the first direction D1. Specifically, in this embodiment, the support fixing part 917 is fixed to the support part 915 in an immovable state. The support fixing part 917 is connected to the side plate 56 in a rotatable state around a virtual axis extending in the first direction D1. The support fixing part 917 extends in the second direction D2.

[0075] The contact portion 912D is movable while in contact with the seabed F. In this embodiment, the contact portion 912D is a plurality of tires that rotate relative to the support portion 915. The two contact portions 912D are disposed spaced apart from each other in the first direction D1 relative to the support portion 915. Therefore, the contact portion 912D rotates while in contact with the seabed F, thereby moving the chamber 5 along the seabed F via the support portion 915.

[0076] The biasing mechanism 92D biases the excavator body 2 so as to press the inclined traveling section 91D against the seabed F. The biasing mechanism 92D biases each of the inclined traveling sections 91D independently. The biasing mechanism 92D damps so as to reduce the impact in the vertical direction Dv generated from the seabed F on the inclined traveling section 91D. The biasing mechanism 92D of this embodiment has a hydraulic cylinder 922 and a spring damper 923.

[0077] Oil is sealed inside the hydraulic cylinder 922. The hydraulic cylinder 922 extends upward in the vertical direction Dv from the arm portion 916. The hydraulic cylinder 922 connects the arm portion 916 and the spring damper 923.

[0078] The spring damper 923 is disposed above the hydraulic cylinder 922 in the vertical direction Dv. The spring damper 923 connects the hydraulic cylinder 922 and the excavator body 2. In other words, the spring damper 923 is connected in series to the hydraulic cylinder 922 between the excavator body 2 and the arm portion 916.

[0079] In this modification, the chamber 5 further includes a chamber support portion 521 and a chamber contact portion 522. The chamber support portion 521 extends from the rear plate 57 toward the rear D1r in the first direction D1. The chamber support portion 521 is fixed to the rear plate 57 in a state in which it cannot move. The chamber contact portion 522 is movable in a state in which it is in contact with the seabed F. The chamber contact portion 522 is a tire that rotates relative to the chamber support portion 521. Therefore, the chamber contact portion 522 may be the same member as the contact portion 912D. The chamber contact portion 522 rotates in a state in which it is in contact with the seabed F, thereby supporting the chamber 5 via the chamber support portion 521 in a state in which it can move along the seabed F.

[0080] According to the dredging device 4D of such a modification, when moving on the inclined seabed F such that only the front D1f of the first direction D1 is located above the vertical direction Dv, the dredging device 4D moves while performing a pitch motion to rotate around a virtual axis extending in the second direction D2 through its center of gravity. Specifically, the arm portion 916 rotates downward in the vertical direction Dv so that the support portion 915 moves away from the excavator body 2. At that time, the hydraulic cylinder 922 and the spring damper 923 connected to the arm portion 916 are extended. As a result, a force acts on the arm portion 916 by the hydraulic cylinder 922 and the spring damper 923 so as to press the arm portion 916 from the excavator body 2 toward the seabed F. Therefore, the contact portion 912D connected to the arm portion 916 via the support portion 915 is also pressed toward the seabed F. In addition, the chamber 5 connected to the support portion 915 via the support fixing portion 917 is also pressed toward the seabed F. As a result, the dredging device 4D performs a pitching motion to press the chamber 5 against the seabed F.

[0081] In addition, a description of the case where the seabed F is inclined so that the rear D1r of the first direction D1 is located above the vertical direction Dv, which is the opposite to the above case, will be omitted. However, in this case, each component of the dredging device 4D moves in the direction opposite to that described above.

[0082] In addition, when moving on the inclined seabed F such that only one side in the second direction D2 is located above the vertical direction Dv, the dredging device 4D moves while performing a roll motion such that it rotates around a virtual axis extending in the first direction D1 through its center of gravity. Specifically, the arm portion 916 rotates upward in the vertical direction Dv so that the support portion 915 located on one side in the second direction D2 with respect to the chamber 5 approaches the excavator body 2. At that time, the hydraulic cylinder 922 and the spring damper 923 connected to the arm portion 916 are compressed. That is, the other arm portion 916 arranged apart in the second direction D2 rotates in the opposite direction. As a result, the position of the tip of the other arm portion 916 arranged apart in the second direction D2 is shifted in the vertical direction Dv. As a result, the pair of support portions 915 arranged apart in the second direction D2 are pressed against the seabed F in a state of being shifted in the vertical direction Dv. In addition, the chamber 5 connected to the support part 915 via the support fixing part 917 is also pressed against the seabed F in a state inclined parallel to the seabed F. As a result, the dredging device 4D performs a rolling motion to press the chamber 5 against the seabed F.

[0083] In addition, a description of the case where the seabed F is inclined so that the other side of the second direction D2 is located above the vertical direction Dv, which is the opposite to the above-mentioned case, will be omitted. However, in this case, each component of the dredging device 4D moves in the direction opposite to that described above.

[0084] In this way, even when the seabed F has an uneven shape, the chamber 5 can be kept positioned in a stable attitude relative to the seabed F while performing pitch and roll movements.

[0085] (Other embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included.

[0086] For example, the chamber 5 is not limited to the above-mentioned structure as long as it has a bottom opening 50 and a front opening 51. The chamber 5 may have a pair of side plates 56 connected to each other at the rear D1r in the first direction D1. That is, the chamber 5 does not need to have a rear plate 57. Furthermore, the chamber 5 does not need to have a curtain portion 59.

[0087] In addition, the side plate 56 and the rear plate 57 are not limited to a structure having the plate main body 581 and the cover portion 582. For example, the side plate 56 and the rear plate 57 may be formed of only one material. In addition, the side plate 56 and the rear plate 57 may be formed to have different configurations.

[0088] The configuration of the suction devices 6, 6C is merely an example, and is not limited to the configuration of the embodiment as long as it is capable of sucking up the gravel, soil, and water from within the chamber 5. For example, the pump of the suction devices 6, 6C may be installed in the dredging devices 4, 4A, 4B, 4C, or may be installed midway along the transfer pipe 62 between the dredging devices 4, 4A, 4B, 4C and a work boat or the like.

[0089] The configuration of the jetting devices 7 and 7A is merely an example, and is not limited to the configuration of the embodiment as long as it is possible to jet high-pressure liquid downward in the vertical direction Dv toward the seabed F in the chamber 5. For example, the jetting devices 7 and 7A may have a structure having only one jetting line 72. Furthermore, the jetting nozzle 71 is not limited to a structure that jets seawater straight in the vertical direction Dv. For example, the jetting nozzle 71 may be arranged at an angle inward so as to face the suction port 61 in the second direction D2. In this way, the jetting nozzle 71 jets seawater away from the side plate 56 and close to the suction port 61, which makes it easier to collect gravel and soil near the center of the chamber 5, which is near the suction port 61. Conversely, the jetting nozzle 71 may be arranged at an angle outward so as to face the side plate 56 in the second direction D2. In this way, the jetting nozzle 71 jets seawater close to the side plate 56, which makes it easier to hit the gravel and soil near the side plate 56 against the side plate 56 and collect the gravel and soil near the center of the chamber 5. Therefore, it is possible to prevent gravel from being left behind near the side plate 56.

[0090] Further, only one excavation device 3 may be arranged for one excavator body 2, or a plurality of excavation devices 3 may be arranged for one excavator body 2. In this case, it is preferable that the same number of dredging devices 4, 4A, 4B, 4C as the excavation devices 3 are arranged.

[0091] <Additional Notes> The dredging apparatus 4, 4A, 4B, 4C and the sea-bed deposit excavator 1 described in each embodiment can be understood, for example, as follows.

[0092] (1) The dredging apparatus 4, 4A, 4B, 4C according to the first embodiment is movable in one direction of a first direction D1 intersecting with a vertical direction Dv, and includes a chamber 5 having a bottom opening 50 facing the seabed and a front opening 51 facing one side of the first direction D1, suction ports 61, 61A, 61B arranged in the chamber 5, suction devices 6, 6C for sucking sand, gravel, soil, and water in the chamber 5 through the suction ports 61, 61A, 61B, and a jet device 6 for jetting liquid toward the seabed in the chamber 5. The chamber 5 has a top plate 55 arranged to face the seabed at a position spaced apart in the vertical direction Dv, and a pair of side plates 56 extending downward in the vertical direction Dv from the top plate 55 toward the seabed and arranged so that the spacing between them becomes smaller with increasing distance from the front opening 51, and the injection device 7, 7A has a plurality of injection nozzles 71 arranged at a distance from each other in the first direction D1 along each of the pair of side plates 56.

[0093] In the dredging device 4, 4A, 4B, 4C, the excavated gravel soil is collected into the chamber 5 from the front opening 51 and the bottom opening 50. Furthermore, the gravel soil collected in the chamber 5 is lifted up by seawater sprayed from the multiple jet nozzles 71 toward the seabed F. At that time, the multiple jet nozzles 71 are arranged along the pair of side plates 56. Therefore, the gravel soil lifted up by the multiple jet nozzles 71 comes into contact with the side plates 56 and tends to gather near the center of the chamber 5. In this state, the gravel soil water in the chamber 5 is sucked from the suction ports 61, 61A, 61B, so that the amount of the gravel soil collected in the chamber 5 left behind can be reduced and sucked up. Therefore, the amount of the excavated seabed resources left behind can be reduced and efficiently collected.

[0094] (2) The dredging apparatus 4, 4A, 4B, and 4C of the second aspect are the dredging apparatus 4, 4A, 4B, and 4C of (1), in which the chamber 5 is formed such that, when viewed from the vertical direction Dv, the position of the front opening 51 in the first direction D1 is widest in a second direction D2 that intersects the vertical direction Dv and the first direction D1.

[0095] According to this configuration, the chamber 5 is widest at the front opening 51 in the second direction D2. Therefore, gravel and soil can be efficiently collected into the chamber 5 through the front opening 51.

[0096] (3) The dredging equipment 4, 4A, 4B, 4C of the third aspect is the dredging equipment 4, 4A, 4B, 4C of (1) or (2), and the multiple injection nozzles 71 are arranged between the suction ports 61, 61A, 61B and the side panel 56 in a second direction D2 intersecting the vertical direction Dv and the first direction D1 when viewed from the vertical direction Dv.

[0097] According to this configuration, the gravel soil stirred up by the multiple jet nozzles 71 is more likely to come into contact with the side plate 56 on one side of the second direction D2 relative to the jet nozzles 71, and approaches the suction ports 61, 61A, and 61B on the other side of the second direction D2. Furthermore, the gravel soil that comes into contact with the side plate 56 bounces back and approaches the suction ports 61, 61A, and 61B on the other side of the second direction D2. In other words, the gravel soil stirred up by the multiple jet nozzles 71 is more likely to gather near the suction ports 61, 61A, and 61B of the chamber 5 without being dispersed within the chamber 5. Therefore, the gravel soil collected in the chamber 5 can be sucked up with less remaining behind.

[0098] (4) A dredging apparatus 4, 4A, 4B, 4C relating to a fourth aspect is any one of the dredging apparatuses 4, 4A, 4B, 4C of (1) to (3), wherein the pair of side plates 56 have a plate main body 581 connected to the top plate 55, and a cover portion 582 connected below the plate main body 581 in the vertical direction Dv and formed of a material or structure softer than the plate main body 581.

[0099] According to this configuration, the plate body 581 can ensure the strength of the side plate 56. In addition, since the cover portion 582, which is likely to come into contact with the seabed, is made of a soft material or structure, even if the side plate 56 comes into contact with the seabed, it can cover the seabed while deforming to follow the shape of the seabed. In other words, the cover portion 582 can deform to pass through a seabed with uneven shapes such as large humps or large ores in gravel while ensuring the airtightness of the chamber 5. Therefore, damage to the side plate 56 can be suppressed while maintaining the efficiency of collecting gravel into the chamber 5.

[0100] (5) The dredging apparatus 4, 4A, 4B, 4C of the fifth aspect is any one of the dredging apparatuses 4, 4A, 4B, 4C of (1) to (4), and the injection device 7, 7A injects seawater outside the chamber 5 as the liquid.

[0101] According to such a configuration, there is no need to prepare a separate liquid to be ejected in the chamber 5.

[0102] (6) The dredging apparatus 4A, 4B relating to the sixth aspect is any one of the dredging apparatuses 4A, 4B of (1) to (5), and is equipped with a swirling flow promotion section 8, 8B that imparts a swirling component to the gravel, soil and water sucked from the suction ports 61A, 61B in the chamber 5.

[0103] With this configuration, a swirling flow is generated while the gravel and soil water is being sucked in from the suction ports 61A and 61B. As a result, the gravel and soil is more easily stirred up. This prevents the gravel and soil from accumulating on the seabed, and reduces the amount of gravel and soil left behind after collection in the chamber 5. This reduces the amount of excavated seabed resources left behind, making collection more efficient.

[0104] (7) A dredging device 4C according to a seventh aspect is any one of the dredging devices 4C (1) to (6), and is provided with an inclined running section 91 that is fixed to the chamber 5 and movable so as to be inclined with respect to a virtual plane perpendicular to the vertical direction Dv while being capable of contacting the seabed, and a biasing mechanism 92 that biases the inclined running section 91 downward in the vertical direction Dv.

[0105] According to this configuration, even if the seabed is not horizontal but inclined, the inclined running part 91 in contact with the seabed is kept in a state of being urged toward the seabed by the urging device while swinging. Therefore, the chamber 5 fixed to the inclined running part 91 can be kept in a position parallel to the seabed. This makes it possible to keep the chamber 5 positioned in a stable position relative to the seabed, regardless of the seabed F's shape, no matter how uneven it is.

[0106] (8) The seabed mineral deposit excavation machine 1 of the eighth embodiment is a dredging device 4, 4A, 4B, 4C which is any one of (1) to (7), and comprises the dredging device 4, 4A, 4B, 4C, an excavation machine body 2 which is arranged above the chamber 5 in the vertical direction Dv and capable of moving in the first direction D1, and an excavation device 3 which is arranged below the excavation machine body 2 in the vertical direction Dv and forward D1f in the traveling direction relative to the chamber 5. [Explanation of symbols]

[0107] 1. Seabed ore drilling machine 2. Excavator body 3. Drilling equipment 31...Rotating drum 32...bit O…Axis line 4, 4A, 4B, 4C, 4D…Dredging equipment 5. Chamber 50…Bottom opening 51…Front opening 55…Tabletop 56…Side panel 57...Rear plate 581…Board body 582…Cover part 59…Makubu S…Space 6, 6C…Suction device 61, 61A, 61B...Suction port 62…Transfer pipe 7, 7A…Injection device 71...Injection nozzle 72…Injection line 721…First injection line 722…Second injection line 73...Injection pump 8, 8B...Swirling flow promotion part 81, 81B... Expanded diameter part O8…center axis 82, 82B... Swivel wing section 821, 821B...Wing base 822, 822B…Wing body 76A…Expanded diameter injection nozzle 77A…Expanded diameter injection line 84...Swivel nozzle 85...Swivel nozzle line 91, 91D…Inclined running section 911…Frame section 912, 912D…Contact part 915...Support part 916…Arm section 917...Support and fixing part 92, 92D...Biasing mechanism 921…Suspension 922...Hydraulic cylinder 923…Spring damper 93...Traction part 65...Flexible tube D1…first direction D1f…Front D1r…backward D2…Second direction Dv: Vertical direction F…Undersea

Claims

1. a chamber that is movable in one direction intersecting a vertical direction and has a bottom opening facing the seabed and a front opening facing the first direction; a suction device having a suction port disposed in the chamber and configured to suck the gravel, soil, and water from the chamber through the suction port; an injection device for injecting liquid into the chamber towards the seabed, The chamber has a top plate disposed to face the seabed at a position vertically spaced apart from each other, and a pair of side plates extending downward in the vertical direction from the top plate toward the seabed, the side plates being disposed such that the distance between the side plates decreases with increasing distance from the front opening, The dredging device has a plurality of jet nozzles arranged spaced apart from each other in the first direction along each of the pair of side plates.

2. The dredging device according to claim 1, wherein the chamber is formed such that, when viewed from the vertical direction, the position of the front opening in the first direction is widest in a second direction intersecting the vertical direction and the first direction.

3. The dredging device according to claim 1 or claim 2, wherein the multiple injection nozzles are arranged between the suction port and the side plate in a second direction intersecting the vertical direction and the first direction when viewed from the vertical direction.

4. The pair of side plates includes a plate body connected to the top plate, A dredging device according to claim 1 or claim 2, further comprising a cover portion connected to the plate body below in the vertical direction and formed of a material or structure softer than the plate body.

5. The dredging device according to claim 1 or 2, wherein the injection device injects seawater outside the chamber as the liquid.

6. The dredging device according to claim 1 or claim 2, further comprising a swirling flow promoting section that imparts a swirling component to the gravel, soil and water sucked from the suction port in the chamber.

7. an inclined traveling section that is fixed to the chamber and is movable so as to be inclined with respect to a virtual plane perpendicular to the vertical direction while being capable of contacting the seabed; The dredging device according to claim 1 or claim 2, further comprising a biasing mechanism for biasing the inclined traveling portion downward in the vertical direction.

8. A dredging device according to claim 1 or 2; An excavator body disposed above the chamber in the vertical direction and movable in the first direction; A seabed ore deposit drilling machine comprising: a drilling device arranged below the drilling machine body in the vertical direction and forward of the chamber in the traveling direction.

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