JPH06104982B2 - Drag head in drag type dredger - Google Patents

Description

The present invention relates to a drag head in a drag type dredger.

(Prior Art) Conventionally, in order to dredge using a drag head, the drag head is attached to the tip of the suction pipe attached to the drag arm provided outside the dredging ship, and the drag head is grounded to the seabed,
It uses a method of pumping up sediment from the sea bottom with a dredging pump while traveling at a constant speed (2 knots to 5 knots). However, in such dredging with a drag head, when performing dredging work on the soft-soil sea bottom, the drag head that is grounded on the sea bottom is buried in the soil, so the drag head generated due to the buried state There was a problem that it was not possible to inhale the sand that climbed up or climbed up to the side.

Therefore, for example, as disclosed in Japanese Utility Model Publication No. Sho 63-22201, the drag head main body having the suction port is provided with a sled to widen the width so as to prevent the drag head from sinking into the earth and sand. Came.

(Problems to be solved by the invention) However, with such a wide drag head, the width of the drag head is considerably larger than the width of the suction port, so that even if the sea bottom is not soft soil, Dredged sand remains in the form of ridges and cannot be inhaled, and the ridge-shaped landslides on the sled or draghead body due to the sinking of the draghead body that accompanies the inhalation of the sand There is a problem.

The present invention has been made in order to eliminate the drawbacks of dredging by such a conventional drag head, and it is possible to inhale even undredged sand that has climbed onto the drag head or has risen to the side surface. It is intended to provide a drag head.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. The drag head of the present invention is attached to the lower end of the suction pipe 1. The lower surface suction port 3 is provided on the lower side of the drag head main body 2, and the spreading sand plate 4 that expands in the traveling direction of the drag head is provided on the upper side of the main body. An upper surface suction port 5 is formed in the portion, and a branch suction pipe 6 communicating with an intermediate portion of the suction pipe 1 is connected.

(Operation) Since the drag head of the present invention is configured as described above, when the pump P1 on the ship is driven, the suction force of the pump P1 causes the suction pressure of the bottom surface of the drag head body 2 landed on the sea bottom The earth and sand will be sucked up by the suction pipe 1 and carried to the ship. At that time, due to the suction of the sediment or the sinking of the drag head into the sediment due to the weight of the drag head, the sediment will rise to the upper surface and the side surface of the drag head main body 2. As a result, it is captured and scraped off by the sediment collecting plate 4, sucked by the branch suction pipe 6 communicating with the suction pipe 1, flows into the suction pipe 1, and is sucked up on the ship. Therefore, conventionally, it becomes possible to lift up the undredged sand that has risen to the upper surface or the side surface of the drag head body, and the dredging can be performed efficiently.

(Example) Hereinafter, the Example of the drag head of this invention is described with reference to drawings.

In FIG. 1 and FIG. 2, reference numeral 1 is a suction pipe whose base end is connected to a pump P1 on a ship and extends into the sea, and a drag head body 2 communicating with the suction pipe 1 is attached to the lower end thereof. There is. The drag head body 2 is formed in a box shape, and a lower surface suction port 3 is opened on the lower side thereof. Drag head body 2
On the upper side of the drawing, there is provided a sand gathering plate 4 that expands in the traveling direction indicated by the arrow a in the figure, and at the base end thereof is provided an upper surface suction port 5 so that it communicates with the middle of the suction pipe 1. Is connected to the branch suction pipe 6.

Therefore, when the pump P1 is driven, as shown by the arrow b in FIG. 2, the sediment on the lower side of the drag head body 2 flows into the suction pipe 1 through the lower surface suction port 3 and is sucked up on the ship. The earth and sand riding on the upper surface of the drag head main body 2 and the earth and sand rising on the side surfaces are trapped by the earth and sand slide plate 4 and flow in through the upper surface suction port 5 as shown by an arrow c in FIG. 6 enters the suction pipe 1, merges, and is sucked up on the ship.

FIG. 3 shows another embodiment of the present invention. In the previous embodiment, the sand from the lower suction port 3 and the upper suction port 5 is sucked up by the same pump P1, but in this embodiment, another pump is provided in the middle portion of the branch suction pipe 6. P2 is provided so that the pumps P1 and P2 can be operated and controlled independently. Therefore, in the case of this embodiment, depending on the dredging conditions, it is possible to adopt various usage methods such as lifting soil from only the lower surface suction port 3 or only from the upper surface suction port 5.

(Effects of the Invention) As described above, the drag head of the present invention is provided with a lower surface suction port on the lower side of the drag head body attached to the lower end of the suction pipe, and on the upper side of the body in the traveling direction of the drag head. The structure is such that a facing sand spreader plate is provided, an upper surface suction port is formed at the base end of the sand sand draw plate, and it is connected to a branch suction pipe that communicates with the middle part of the suction pipe. It is also possible to inhale undredged sand that has climbed up the side of the head body or that has risen to the side, and it is possible to increase the amount of sediment that is dredged compared to conventional drag heads, and also to increase the leveling area, etc. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view of the same main portion, and FIG. 3 is a perspective view showing another embodiment. 1 ... Suction pipe, 2 ... Drag head body 3 ... Bottom suction port, 4 ... Sedimentation plate 5 ... Top suction port, 6 ... Branch suction pipe P1, P2 ... Pump

Claims (1)

[Claims] 1. A lower surface suction port is provided on the lower side of a drag head main body attached to the lower end of an intake pipe, and an earth spreading plate that expands in the advancing direction of the drag head is provided on the upper side of the main body. A drag head in a drag type dredger, characterized in that a top suction port is formed at a base end portion of a sand gathering plate, and a branch suction pipe connected to an intermediate portion of the suction pipe is connected to the sand suction plate.