JP5856053B2 - Cutter head for dredging the ground, cutter suction dredger with such a cutter head, and method for dredging the ground - Google Patents

Description

The present invention relates to a cutter head for dredging the ground under the surface of the water, and this cutter head is suitable for attaching a cutter suction dredger to a ladder and moving the ground by a ladder in a lateral sweeping motion. The invention also relates to a cutter suction dredger with such a cutter head and a method for dredging the ground, in particular the relatively hard ground.

  A cutter head of the type described in the preceding paragraph is known, for example, from NL1031253. A known cutter head is a swivel that is rotatable about a central axis, the swivel being formed by a base ring and a hub arranged concentrically at a distance from the base ring. In between, a plurality of support arms with drilling tools extend. The known drilling tools are bit-like, meaning that they comprise flat portions at their outer free ends and at their end faces contact the ground over a defined linear distance. For a good excavation operation, the excavation tool must first contact the ground during rotation of the known cutter head. Therefore, the excavation tool is located at the leading portion of the support arm when viewed in the rotation direction of the cutter head.

  The cutter head is applied in combination with a cutter suction dredger (also called a cutter dredger). The cutter suction dredger includes a ship fixed to the ground by a so-called spud post. Because of this fixation, the reaction force generated in the cage can be transmitted to the ground and absorbed. A suction pipe is attached to the ladder of the cutter suction dredger, and the suction pipe is connected to the cutter head, along which the dredged ground is removed. During the dredging, the cutter head begins to rotate, and the ladder and the suction pipe are lowered into the water at an oblique angle as a whole and come into contact with the ground. The cutter head is dragged across the ground by pulling the ladder alternately from port to starboard using a winch. The cutter head rotates about the cutter head axis-the line connecting the center of rotation of the base ring and the hub-so that the end face of the excavation tool receives the weight of the cutter head, ladder, and suction pipe with a large force. It hits. Debris generated thereby is sucked up by the suction pipe and discharged through the passage opening between the support arms. The entire ground surface can be dredged by moving the cutter suction dredger at once over a predetermined distance and repeating the sweeping motion described above.

  U.S. Pat. No. 4,319,415A discloses a cutter head for a cutter. The cutter head includes a revolving body that can rotate around a rotation axis, and the revolving body is formed by a base ring and a hub that is disposed at a slight distance from the base ring. The support arm extends. The support arm includes a tooth holder for incisors. The tooth holder has a T-shaped profile so that it can be releasably attached to the support arm.

  WO 2005 / 035884A describes a robotic manipulator for removing worn teeth from a dredger's cutter head and for replacing the removed teeth with new ones. The manipulator is installed on the dredger. The disclosed cutter head is of the usual type including about 5 support arms each having about 8 teeth.

  GB-A-2024492 discloses a cutter head that includes a central hub on which at least one helical helical web is mounted. The web includes an array of cutter bits that are spaced along the web and project so that successive bits on the same web in use dig deeper than the previous bit in use.

  NL-A-8104969 discloses a conventional cutter head for a cutter suction dredger that includes a normal amount of five support arms, each fitted with about eight teeth.

  U.S. Pat. No. 4,470,210A discloses an adapter for a cutter head. The adapter is rotatable about the vertical and horizontal axes so that the optimum excavation angle of the incisor can be adjusted.

  U.S. Pat. No. 4,986,611 A discloses a cutting tooth for a cutter dredger that can be attached to the support arm of the cutter head by means of a clamping portion of the cutting tooth in the adapter using intermittent flexible elements.

  Known cutter heads are capable of dredging relatively hard ground, eg rock, defined in the context of the present application as having a uniaxial compressive strength (UCS) of at least 50 MPa, or with limited efficiency. There is a drawback of either. UCS is a concept known to those skilled in the art and indicates the compressive strength of the ground, and the side walls of the ground are not supported during compression. Efficiency is understood in the context of the present application to mean the volume of ground that is drowned per unit time and unit power.

  The object of the present invention is, in addition to other advantages, a cutter that can dredge the surface of the ground more efficiently and increase the efficiency compared to known cutter heads, particularly capable of dripping a relatively hard type of ground. It is to provide a cutter head for a suction dredger.

  According to the invention, for this purpose, a cutter head comprising a pivoting body rotatable about a central axis, the pivoting body being constituted by a base ring and a hub arranged slightly away from the base ring. A plurality of support arms formed between the base ring and the hub are formed, the cutter head comprises at least 50 drilling tools, and the drilling tools are preferably at least at their outer free ends. Are axisymmetric along their entire length, thereby providing cutter heads that are free to rotate about their longitudinal axis. In particular, it has been found that a relatively hard ground, in particular, for example rocks, can be dredged with higher efficiency than known cutter heads by providing an excavation tool that is axisymmetric on the side in contact with soil on the support arm of the cutter head. . It has been found that the excavation tool being axisymmetric has a positive effect on the destruction of the ground, in particular the relatively hard ground.

  Known drilling tools are relatively wide at their outer free ends and can withstand the large forces experienced in the cage. The weight of the underwater part of the cutter suction dredger is ultimately distributed over the contact surface area between the drilling tool and the ground. By providing a relatively wide outer free end to a known excavation tool, this contact surface area is relatively large, whereby the force transmitted to the ground is distributed over a relatively large surface area. Therefore, the average pressure on the contact surface remains limited, thereby avoiding breakage of the drilling tool.

  Since the excavation tools according to the invention are axisymmetric at least at their outer free ends and come into contact with the ground at this part, the excavation tools can enter the ground with relatively little force. Furthermore, the pressure applied locally to the ground is relatively high, thereby effectively crushing the ground, especially the relatively hard ground.

  U.S. Pat. No. 4,488,608 A discloses a rotary stone cutting head for excavating dry rock or the like having a conical excavation tool, a part of which includes a hardened (tungsten carbide) insert. State that the cutting head is described. Tools with inserts are positioned somewhat deeper than other cutter tools to avoid premature failure when in contact with an irregular rock surface.

  DE 10 2005 051450 A1 discloses an axisymmetric drilling tool that in some cases can freely rotate about its rotational symmetry axis, while US Pat. No. 4,575,156 A is similar to that used in coal mining. This relates to an axisymmetric drilling tool. Neither document suggests using such tools for dredging in water.

  A preferred embodiment of the cutterhead is characterized in that the excavation tool is rotationally symmetric and more preferably has a conical shape. Such a geometry allows a higher average pressure to be transmitted to the ground than is possible with known drilling tools. Another advantage of the drilling tool according to the invention, in particular the preferred conical variant, is that it occupies less space than known drilling tools because of its shape. This has made it possible to provide a cutter head with a large number of excavating tools, which has been found to be advantageous for the dredge efficiency of the cutter head. For the same reason, the passage openings that exist between the support arms of the cutter head and discharge the crushed ground can likewise be made smaller than in the case of known cutter heads. This is because the excavation tool according to the present invention does not disturb the passage so much. Thereby, the number of support arms can also be increased.

  According to another preferred embodiment of the present invention, the excavation tool includes a substantially cylindrical shank portion that is reduced in diameter relative to the conical top. The excavation tool according to this embodiment is arranged such that the coupling means provided on the arm of the cutter head has its cylindrical shank portion. The coupling means preferably includes a block socket with a central hole into which a cylindrical shank portion is inserted for rotation. In this embodiment, the conical portion protrudes outside the block socket over an effective length, which is relatively short compared to the overall length of the excavation tool. This has the advantage that it can withstand much greater forces than prior art incisors. Further, the block socket effectively supports the excavation tool against bending deformation. In a preferred embodiment, the excavation tool projects outside the holder by a length of 10-500 mm, more preferably 20-250 mm, and most preferably 50-150 mm.

  In a particularly preferred embodiment, the excavation tool is preferably arranged in its socket so that it can rotate freely or at least easily about its rotational symmetry axis. This is possible because the excavation tool is rotationally symmetric. Enabling free or easy rotation of the tool during operation reduces the risk of breakage of the tip of the drilling tool in contact with the soil and also the risk of spontaneous cutting due to friction with the soil. This increases the useful life of the drilling tool and saves valuable time because it does not require frequent replacement of broken or pointed drilling tools.

  The conical portion of the drilling tool is preferably provided with a hardened tip in contact with the soil at the outer end. The tip can be made of carbide, for example.

  In another preferred embodiment, the cutter head according to the present invention has a radius of curvature at the top of the conical drilling tool of at most 500 mm, more preferably at most 350 mm, even more preferably at most 100 mm, and most preferably at most 50 mm. Features. Yet another preferred variant includes a conical excavation tool, the upper radius of curvature of which is 1-100 mm, and more preferably 5-80 mm. In yet another preferred variation, the excavation tool includes a holder that houses a conical cemented carbide insert.

  A preferred embodiment of the cutter head according to the invention is characterized in that the cutter head comprises at least 5 support arms, more preferably at least 10 support arms, and most preferably at least 15 support arms. It is also possible for the cutter head to include a swiveling surface with a passage opening between the base ring and the hub. Here, the part of the swiveling surface between the openings forms the “support arm” of the cutter head. Another option is to provide the cutter head with an axially extending support arm on which a circumferentially extending lateral arm is mounted.

  The number of drilling tools can be varied within wide limits and it is advantageous for the number of drilling tools to be as large as possible. In a preferred embodiment, the cutter head according to the present invention comprises at least 100 excavation tools, even more preferably at least 140 excavation tools, and most preferably at least 180 excavation tools. Here, the excavation tool can be distributed regularly and irregularly over the turning surface of the cutter head. The number of drilling tools per support arm is preferably at least 10 drilling tools, more preferably at least 15 drilling tools, more preferably at least 20 drilling tools, and most preferably at least 25 drilling tools. .

  The cutter head according to the present invention excavates the ground in a fundamentally different manner from known cutter heads. Whereas known cutter heads strike the ground with great force into large pieces, the cutter head according to the present invention breaks the ground into much smaller pieces. Since more drilling tools are in the direction of cutter head rotation, the ground is drilled more rapidly and continuously. This work has been found to be more efficient, especially on hard ground.

  The support arm includes a first series of excavation tools at a leading portion when viewed in the direction of rotation of the cutter head, and at least one support arm has a second series of excavations at a portion facing away from the central axis. It has further been found that it is advantageous to include a tool. Although it is unusual to provide an excavation tool on the portion of the support arm that faces outward from the central axis, efficiency can be increased. Surprisingly, the connection of the excavation tool to the part of the support arm that faces away from the central axis is sufficiently strong to transmit the force generated by the excavation tool that hits the hard arm, for example rock, to the support arm. I found. More excavation tools can be placed on a single support arm in this way than with the prior art. This is particularly advantageous for relatively hard ground dredging.

  In an advantageous embodiment, the first series of drilling tools on the support arm is offset with respect to the second series of drilling tools. This further increases the efficiency of the dredging process. Since the excavation tool is displaced, the work area of the excavation tool is widened. This is because the second series of drilling tools is not disturbed by the first series of drilling tools.

  In yet another embodiment, the support arm has a length and the excavation tool is located on both sides of the center of the support arm along up to 80% of the length of the support arm. While no negative impact on the efficiency of the cutter head due to the absence of a drilling tool near the outer end of the support arm has been found, this measure simplifies the construction of the cutter and is therefore inexpensive. On the other hand, the presence of a drilling tool near the cutter head hub is advantageous for advancing the cutter head.

The excavation tool is connected in particular to the support arm by means of coupling. This facilitates exchanging excavation tools that may be required as a result of wear or damage. Here, it is advantageous to connect the coupling means itself with the support arm, such as by using a weld connection.

  In a preferred embodiment of the cutter head according to the invention, the support arm of the cutter head comprises a guide on which the coupling means and / or the excavation tool is mounted so as to be displaceable. Suitable guides include, for example, guide rails on which coupling means and / or excavation tools can slide. This preferred variant has the advantage that the coupling means and / or the excavation tool can be easily displaced. Therefore, the intermediate distance between the excavating tools can be adjusted in a simple manner depending on the characteristics of the ground, in particular the hardness.

  The invention also relates to the use of a cutter head according to the invention for excavating a ground part with a uniaxial compressive strength (UCS) of 50-200 MPa, preferably 60-150 MPa and most preferably 80-100 MPa. Regarding the advantages of using a cutter head, reference is made to the advantages of the cutter head according to the invention described above.

  The invention also relates to a cutter suction dredger comprising a cutter head according to the invention. The cutter suction dredger equipped with the cutter head according to the present invention can dredge the ground, particularly the relatively hard ground, that is, the ground having a UCS of more than 50 MPa with high efficiency.

  The present invention will now be further described with reference to the drawings and description of preferred embodiments, without limiting the invention thereto. The drawings are not necessarily to scale.

FIG. 2 is a schematic side view of a portion of a cutter suction dredger with a ladder attached and comprising a cutter head according to the present invention. It is a perspective view of the cutter head by this invention. 1 is a detailed side view of an excavation tool according to the present invention. FIG. 6 is a detailed side view of an excavation tool according to another embodiment of the present invention. FIG. 6 is a detailed side view of an excavation tool according to yet another embodiment of the present invention.

  FIG. 1 shows a cutter suction dredger 1 with a ladder 2 mounted so as to be pivotable about a horizontal axis 3. The ladder 2 comprises a suction pipe 4, which can suck up loose parts of the ground to a level above the water surface 100, which is then discharged. The ladder 2 is pulled on the ground surface 9 by a winch 5 placed on the deck of the cutter suction dredger 1 to dredge or break. The winch includes a plurality of swing winches (not shown) and a ladder winch 8. The ladder 2 includes a cutter head 10 according to the present invention at the outer end thereof. The cutter head 10 can be lowered into the water by a ladder winch cable 8 and can be moved over the ground surface 9 during use by a reciprocating sweeping movement of the cutter suction dredger 1 from port to starboard and vice versa. In order to be able to absorb the forces generated here on the ground surface, the cutter suction dredger 1 is fixed to the ground by a spud post 101. FIG. 1 shows the spud post in the left (starboard) unfixed position and the spud post in the right (starboard) fixed position.

  Referring to FIG. 2, the cutter head 10 according to the present invention includes a revolving body 11 that can start to rotate around its rotation axis 12 by driving means (not shown). In this document, the rotating shaft 12 coincides with the central axis of the cutter head 10. In the illustrated embodiment, the swivel body 11 begins to rotate in a clockwise direction R as viewed from the bridge. Support arms 15 extend in a spiral manner between the base ring 13 and a hub 14 arranged at a distance from the base ring 13, and these support arms 15 are connected to the base ring 13 and the hub 14. Here, the support arm 15 has an arch shape, and the convex side faces the rotation direction R. The base ring 13, the hub 14 and the support arm 15 are substantially made of steel. This not only hardens the cutter head 10, but also increases the weight of the cutter head 10, so that the cutter head 10 is pushed in the direction of the ground for the heel under the influence of gravity. In this document, the support arm 15 is regularly arranged around the cutter head 10. A passage opening 16 is disposed between the support arms 15. A substantially steel coupling means 17 is welded to the front edge 15a of the support arm 15 with respect to the direction of rotation of the cutter head 10 in order to couple a first series of excavation tools to the support arm 15. . The coupling means 17, which is also substantially made of steel, is connected to the edge of the support arm 15 facing away from the central axis of the cutter head 10 in order to couple the second series of excavation tools 20 to the support arm 15. 15b to be welded. The coupling means 17 is oriented such that the front side of the first and second series of excavation tools 20 or the side that contacts the ground face in the rotation direction R.

  Referring to FIG. 3, an embodiment of a drilling tool 20 is shown. The illustrated excavation tool 20 having a full length 27 includes a substantially cylindrical portion 22 of diameter 25 and a conical second portion 23. The excavation tool 20 can be arranged such that, for example, by means of a snap connection 220, the aforementioned coupling means 17 of the cutter head 1 has a cylindrical part 22. Permanent connections or other forms of release connections are also possible. In the situation where the excavation tool 20 is arranged on the coupling means 17, the conical part 23 projects over an effective length 26 outside the coupling means or holder 17. The conical portion 23 of the drilling tool 20 comprises a hardened tip 28 at the outer end that contacts the soil. The appropriate radius of curvature at the top of the drilling tool 20 is preferably between 1 and 100 mm, depending on, among other factors, the characteristics of the ground and the specific design of the cutter head. The suitable total length 27 of the excavation tool 20 is preferably 20 to 400 mm in total. Suitable transverse dimensions 25 are preferably 10 to 100 mm in total. In a preferred embodiment, the length 26 of the excavating tool 20 protruding outside the holder 17 is 10-500 mm, more preferably 20-250 mm, and most preferably 50-150 mm.

  4 and 5, the excavation tool 20 is preferably coupled to the support arm 15 by coupling means 17 in the form of a block socket with a central hole 170, in which the excavation tool 20 is prepared for rotation. The cylindrical shank portion 22 is inserted. In the embodiment of FIG. 4, a conical portion 23 with a carbide tip 28 projects outwardly from the block socket over a relatively short effective length compared to the overall length of the excavation tool 20. The block socket 17 supports the excavation tool 20 against bending deformation, and can transmit a large compressive force in the axial direction 171 of the excavation tool 20. The excavation tool 20 is inserted from the left side into the central hole 170 until the snap connection 220 engages the corresponding annular groove 221 in the socket. In the engaged state, the excavation tool 20 is rotationally symmetric, so that the excavation tool 20 can freely rotate about the axis 171 in the central hole 170. This rotation may be somewhat hindered by frictional forces between the outer surface of the shank portion 22 and the inner surface of the central hole 170 or between the contact surface of the socket and the conical portion 23, but is essentially free to rotate. .

  Another embodiment shown in FIG. 5 uses a separate retaining ring 172 with a slot 173, allowing it to be compacted by compressing it. When engaged with the corresponding annular groove 221 (as in the embodiment shown in FIG. 4), the retaining ring expands to make the outer surface of the shank portion 22 rotatable. Locking of the excavating tool 20 in the axial direction 171 is achieved by engaging the rear portion 222 of the excavating tool 20 with the annular ring 172.

  The cutter head of the present invention is particularly suitable for breaking relatively hard ground, is a self-generated blade and has an extended service life.

Claims (10)

A cutter head (10) for dredging the ground under the water surface,
The cutter head includes a swivel (11) rotatable about a central axis, the swivel being formed by a base ring (13) and a hub (14) arranged at a distance from the base ring. A plurality of support arms (15) with excavation tools (20) extend between the hub and the hub, and there are passage openings (16) between the support arms (15), which are rubbed Drain the ground,
The excavation tool (20) is attached to the support arm (15) by means of coupling means (17), the cutter head comprises at least 50 excavation tools, the excavation tool (20) at least at their outer free ends axially symmetric der is,
The excavation tool (20) is arranged on the support arm (15) such that it can freely rotate about their rotational symmetry axis ;
The support arm (15) is provided with a first series of excavation tools (20) at the head portion (15a) when viewed in the rotational direction of the cutter head (10), and faces outward from the central axis. Cutter head (10) , characterized in that it comprises a second series of excavation tools (20) in the part (15b ). The drilling tool (20) is characterized in that it is a conical cutter head according to claim 1 (10). Cutter head (10) according to claim 1 or 2 , characterized in that the radius of curvature at the outer free end at the top of the conical excavation tool (20) is at most 50 mm. Said cutter head (10) is characterized in that it comprises at least 10 of the support arm (15), the cutter head according to any one of claim 1 to 3 (10). Cutter head (10) according to any one of claims 1 to 4 , characterized in that the support arm (15) comprises at least 20 excavation tools (20). The excavation tool (20) is oriented relative to the support arm (15) such that the excavation tool hits the ground surface substantially perpendicularly during rotation of the cutter head through the ground. The cutter head (10) according to any one of claims 1 to 5 . Wherein the same supporting arm (15) on the first series of cutting tools (20) are arranged offset with respect to said second series of cutting tools (20), in claim 1 The cutter head (10) as described. The support arm (15) of the cutter head includes a guide, on which the coupling means (17) and / or the excavation tool (20) are movably mounted. Item 8. The cutter head (10) according to Item 7 . A method of crawling the ground with a uniaxial compressive strength (UCS) of at least 50 MPa,
A ship fixed to the ground by a spud post (101), a ladder (2) with a cutter head (10) according to any one of claims 1 to 8 attached to the tip, and attached along the ladder Prepare a cutter suction dredger (1), including a suction pipe (4) to remove the drowned ground,
The cutter head, together with the ladder and the suction pipe, is lowered into water until it contacts the ground at an oblique angle,
Start rotating the cutter head,
And the dredging method characterized in that the cutter head is dragged by alternately pulling the ladder from the port side to the starboard side using a winch. A cutter suction dredger (1) comprising the cutter head (10) according to any one of claims 1 to 8 .

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