JPH047250Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is an improvement of the drag head used for drag suction dredging, in particular, by attaching a disc-shaped plow to the drag head, it can be used for dredging not only sandy silt but also clay silt. , a plow that enables appropriate dredging of various objects to be dredged, which was not possible with conventional drag heads, by dredging by plowing up and peeling off soft consolidated silt, etc., and applying appropriate ground pressure to the heel pad of the drag head. The present invention relates to a drag head for dredging with a drag suction.

[Prior art and problems to be solved by the invention] When dredging a port or river, the purpose of dredging,
There were also various types of dredging based on differences in soil quality such as sludge, soil, gravel, etc. that were to be dredged.

When dredging mainly soft dredged soil, a suction head is pushed into the seabed and riverbed to improve dredging efficiency, and the dredged soil is pumped out together with treated water.

In addition, if the dredged soil is compacted with sludge-like sandy silt or coarse sand containing gravel, or clayey silt, the dredging efficiency of the above method will be low, so a jet nozzle is added to the drag head, A method has been used in which these soils are disintegrated and lifted out using the jet pressure of the jet stream from the jet nozzle.

However, if the soil to be dredged has a rock-like appearance such as coral or earthen, or even if it is not compacted like this, it may have a highly viscous soil such as clay. There is naturally a limit to the collapse caused by the jet stream in the case of
Dredging was carried out using a drag head with a rotating cutter, bucket wheel, etc. for excavation or stripping.

However, in dredging using rotating or self-rotating cutters such as screws and bucket foils, if the target soil is cohesive silt or soft compacted silt with high consistency, the mud may form in the cutter structure. This sticks, reducing the effect of the cutter's raking into the mud, and also causes the entanglement of long objects such as wires, making it necessary to remove these objects. In addition, drag heads having such drive cutter devices have the disadvantages that they have a complicated structure, are expensive, are complicated to operate, and have high running costs.

Next, in the conventional wedge-mounted dragheads, ground pressure is obtained by their own weight, so when dredging rock-like soil or highly viscous soil, the thrust of the vessel, the strength of the drag arm, and the ground contact are There are limits to pressure, etc., and when these types of soils are encountered, wedges tend to heave up, and as the wedges slide on these, the ability to rake and dredge is often lacking, and furthermore, this wedge This had the disadvantage that the mud content decreased as the soil rose. In addition, although the wedge fixed to the grate of the drag head has an effective dredging function for sandy silt or gravel, in highly viscous soil, these muds adhere to the front of the wedge. This had the disadvantage that the scraping function of the wedge was inhibited, and the mud content decreased as described above.

Furthermore, the grate of the drag head is equipped with claws that protrude downward, and dredging is performed by using these claws to break up the dredged soil. Sediment adheres to the dredging function, causing a decline in the dredging function, and the width of the claws acts as resistance. Compared to the magnitude of this resistance, the width of destruction of the dredged soil is small, and the dredged soil, etc. The dredged soil could not be lifted upwards because only a groove with the same width was formed, resulting in the same problem as the above-mentioned decrease in mud content.

[Specific means for solving the problem] The drag head according to this invention was devised in view of the inconveniences of the conventional drag head for drag suction dredging. A plow is installed on the side of the movable part under the center, and is used to plow up sludge-like or low-viscosity mud, light sand, sandy silt, coarse sand containing gravel, etc. The plow is used to bite into soils such as highly viscous or hard compacted silt, soil slag, and coral, to uplift and collapse these highly viscous or hard objects to be dredged, and to prevent the side of the plow from moving in the descending direction. A thrust force is applied to the head, which is received by the heel butt to provide appropriate ground pressure to the head.

With this intention in mind, in this invention, the structure of the drag head used for drag suction dredging is as follows. That is, the drag head is installed at the free end of the drag arm, and the drag head includes a head fixing part connected to the arm, and a shaft mounted to the head fixing part so as to be able to swing vertically. The head movable part has a casing shape with an open bottom, and the bottom of the head movable part has a plurality of blades extending in the direction of movement of the drag head and having cutting edges directed toward the head fixing part. A disc-shaped plow is attached to one or both sides of the plow, and on one or both sides of the plow there is a bulge extending obliquely upward from the lower end of the cutting edge side of the plow to the upper side of the back of the plow, and gradually bulging outward. This drag head for drag suction dredging is provided with a twisting surface.

[Example] Hereinafter, a typical example of a drag head used for drag suction dredging according to the present invention will be described with reference to the accompanying drawings.

First, the drag head A according to this invention is installed on a dredging vessel B which has a dredging pump a required for dredging work, a dirt tank b for storing dredged sand and mud, etc., and the drag head is suspended so as to be able to rise and fall. Arm C
The drum arm C is attached to the free end of the drum arm C to transport the dredged mud and sand by the dredging pump a to the mud tank b.
It plays a role in supplying

Such a drag head A is composed of a head fixing part A' which is provided continuously on the drag arm C, and a head movable part A'' which is pivotably mounted on the head fixing part 1. Regardless of the arm angle of the drag arm C, the opening of the head movable part A'' is made to come into close contact with the dredging surface.

Next, the head fixed part A' has bearing metal fittings 2 and 3 as a pivot structure for the shaft 1 part, serves as a shaft for the shafts 4 and 5, and serves as a pivot support for the head movable part A''. , a funnel-shaped mud collection chamber 6 is constructed that is continuous with the dredging pipe of the drag arm C, and a jet pipe 7 is introduced into the mud collection chamber 6.

The movable part of the head is connected to the fixed part A' of the head.
A'' has a flat housing shape that gradually becomes thinner toward the tip and has an open bottom surface.A grade 8 is attached to the bottom surface of the movable head part A'' in a lattice pattern. The inside of the head movable part A'' partitioned by 8 is a scraping chamber 9, and the scraping chamber 9 and the mud collection chamber 6 are in communication with each other.

Further, the jet pipe 7 is introduced into the shaft support between the head fixed part A' and the head movable part A'' through the jet water box 10, and the mounting angle of the jet pipe 11 can be freely adjusted from front to back and left and right with respect to the ground surface. Jet nozzles 12 to 12 are installed, and the jet nozzles of the nozzles 12 are set at an angle that matches the quality of the dredged soil, and are fixedly positioned to force the collapse of the soil mass by spraying sand and mud.

In addition, for the purpose of adjusting the ground pressure of the movable part itself, the head movable part A'' has a substantially U-shaped planar shape, and a weight 14 is appropriately placed in the middle of the head movable part A''. It is designed to be stackable.

In addition, 15 in the figure is a water intake port for adjusting the dredging pump a to prevent cavitation, and 16 is a water intake port for adjusting the dredging pump a to prevent cavitation.
a, 16b are guide rods and slider grooves that restrict the swinging of the head movable part A''; 17 is a heel pad that protects the head contact area from wear and restricts the descending force of the plow 19, which will be described later; 18 indicates a fender for protection against contact with the hull.

Such a head structure is equipped with a disc-shaped plow 19 for the purpose of imparting a raking effect suitable for the object to be dredged to the head, particularly to the moving part of the head.

The equipped plow 19 needs to be replaced when it wears out or is damaged, and it also needs to be attached or detached depending on the nature of the object to be dredged, so it can be attached or detached using a driving trowel 20, a key plate 21, etc. It can be installed freely.

The plow 19 typically includes a rectangular plate-shaped mounting portion 19a and a plate-shaped blade portion integrally provided with the mounting portion 19a along the lower surface of the rectangular plate-shaped mounting portion 19a. 19b, the mounting portion 19a is provided with a coulter insertion hole 19c and a hook 19d facing each other, and the plate-shaped blade portion 19b is a coulter with both or one of its surfaces curved. It is said to be the shape.

That is, the blade portion 19b has both surfaces or one surface bulging out toward the rear from the front end x of the blade portion 19b, which is plate-shaped, with respect to the attachment center line of the attachment portion 19a.
Moreover, it has a surface that bulges out from the upper part of the blade part 19b toward the lower end y. As a result, the blade portion 19b has a plow surface m spirally twisted from the lower part of the front end x toward the upper rear side, and this plow surface m provides the blade portion 19b with a so-called plow-up function. In addition, the above-mentioned descent force is generated.

In the embodiment, an example is shown in which the shape of the plow 19 is such that the plow face m is provided only on one side of the blade portion 19b, but the plow face m may also be provided symmetrically on the left and right surfaces of the attachment center line of the blade portion 19b. There are also various curvatures of the plow face m.

The shape, curvature, etc. of such plow face m are determined by the thrust of the equipped ship,
The design will be changed depending on the dredging capacity and strength of the drag arm.

Incidentally, the plow 19 is often rapidly worn during dredging, so the front end x and the plow surface m of the blade portion 19b may be particularly covered with a carbide material or the like, or the front end x and the plow surface m may be replaced. By doing so, dredging costs can be expected to be reduced.

The plow 19 having such a configuration is inserted into the hole provided mainly on the lower surface of the grate 8 through the hole 19c of the plow 19, and the key plate 21 is hammered into the hole at the insertion end of the plow 19. Attach it so that the blade part 19b faces the head fixing part A'.

Furthermore, when attaching the plows 19, the plows 19 are arranged in pairs so that the plow faces m, which are twisted into a spiral shape, are symmetrical as shown in FIG. 6 to prevent meandering of the drag head.

[Function] The drag head for drag suction dredging according to this invention has the following functions based on the configuration described above.

That is, the plow 19 installed in the head A can be used not only for soft mud with low consistency, light sand, sandy silt, etc., but also for highly viscous mud such as clayey silt, and for corral. Even with hard dredged soil, the resistance is only at the front end The dredged soil on the side of the plow surface m can be plowed up without the need for a plow, and by floating the dredged soil, a relative descending force is applied to the plow 19, and the drag head A is always kept on the dredged soil surface. The drag head A is brought into close contact with the drag head A, thereby providing good ground pressure.

The ground pressure exerted on the drag head A is divided into a fixed head part A' and a movable head part A'', and the movable head part A'' is equipped with a plow 19, so that the ground pressure is applied to the drag arm. C
drag head A without being affected by the arm angle of
It has the function of pulling the material into close contact with the dredged mud surface.

Further, the thrust generated by the plow 19 in the plowing direction is received and balanced by the heel pad 17 of the drag head A, and within the range where the reaction force of the plow 19 is received by the heel pad 17, the plow 1
9 is to plow up mud.

Plowing by the plow 19 has the function of plowing up mud on the plow surface m while applying turning force to the mud without adhering or binding the mud to the plow surface m.

The ground pressure is applied to the drag head A by the plow 19, and at the same time as the dredged mud is plowed up, jet water is injected from the jet nozzle 12,
By pumping this up with pump a, it was possible to dredge for all types of soil.

[Effects] The drag head for drag suction dredging according to this invention has been found to have the following effects based on the above-mentioned structure and operation.

That is, even if the mud to be dredged is compacted dredged soil with high viscosity and rock-like appearance, the front end of the plow 19 cuts vertically into the dredged soil to lift the dredged soil without resistance. The twisting creates cracks in the dredged soil, making it easier to plow up the dredged soil on the side of the plowing surface m, which has the advantage of increasing the mud content.

In addition, even in highly viscous dredged soil, the plow surface m of plow 19
In addition, unlike previous nails, these mud particles no longer bind together.

Furthermore, by harmonizing the forced descending thrust generated by the plow 19 and the reaction force received by the heel pad 17, it is possible to dredge at a uniform depth regardless of the properties of the mud to be dredged.

Furthermore, since the plows 19 are mounted symmetrically, they serve as a rudder for the dredged soil, and can prevent the drag head from meandering due to slopes and undulations on the seabed and river bed.

Furthermore, the impact generated on the plow 19 from the opposite direction during plowing is caused by the impact on the movable part of the head.
Since the shaft 1 is pivotably mounted on the head fixing portion A', the impact force is dispersed and damage to the plow 19 can be prevented.

In addition, the plow 19 has no movable or driving parts, and has the advantage of being simple in terms of equipment, resulting in lower equipment costs.Also, since it does not have a rotating mechanism, it can easily handle long pieces of wire, etc. during dredging. Dredging efficiency was improved because miscellaneous objects did not become entangled, and the work efficiency was improved because there was no need to remove such long miscellaneous objects. Particularly in drag heads used for towing under severe conditions, such a simple plow structure has the advantage of avoiding frequent accidents.

As is clear from the above points, by attaching a plow to the drag head, it is possible to reliably and easily dredge various types of soil that were conventionally considered difficult or impossible, and the operation cost is low and the work is easy. It also has characteristics that are considered good.

[Brief explanation of the drawing]

Figure 1 is a side view of a dredger equipped with a drag head according to this invention, Figure 2 is a plan view of the same, Figure 3 is a perspective view of the drag head, Figure 4 is a side view of the same, and Figure 5 is a side view of a dredger equipped with a drag head according to this invention.
The figure is a partially cutaway plan view, Figure 6 is a partially cutaway front view,
Figure 7 is a side view showing the attachment part of the plow, Figure 8 is a side view of the plow, Figure 9 is a perspective view of the plow, Figure 10 is a front view of the same, Figure 11 is a bottom view of the same, and Figure 12 is a side view of the plow. 13 is a sectional view taken along line A-A, FIG. 14 is a sectional view taken along line B-B, and FIG.
-C line sectional view Figure 15 is a DD line sectional view. In addition, in the figure 1... bearing hardware, 2, 3... bearing hardware, 4
... shaft, 5 ... shaft mounting, 6 ... mud collection chamber, 7 ... pipe, 8 ... grade, 9 ... scraping room, 10 ... water box, 11 ... pipe, 12 ... nozzle, 13...time, 14...wait, 15...
...Suction port, 16a...Guide rod, 16b...Slider groove, 17...Heel pad, 18...Fender, 19...Plow, 20...Cotter, 21...
... plate, A... drag head, B... dredger, C... drag arm.

Claims (1)

[Scope of utility model registration request] A drag head installed at the free end of a drag arm, the drag head comprising a head fixing part connected to the arm, and a head pivotably mounted on the head fixing part so as to be able to swing vertically. The head movable part has a casing shape with an open bottom surface, and the bottom surface of the head movable part has a plurality of blades extending in the direction of movement of the drag head and with cutting edges directed toward the head fixing part. A disc-shaped plow is attached, and on one or both sides of the plow there is a twist that rises obliquely from the lower end of the cutting edge side of the plow to the upper side of the back side of the plow and gradually bulges outward. A drag head for drag suction dredging having a plow characterized by being provided with a surface.