JPH0452290Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present application is an invention relating to a vertical screw excavator that is vertically installed and moves by pushing up earth and sand at the bottom.

[Conventional technology] Existing dams are filled with sediment flowing from upstream mountains much faster than originally planned, reducing the supply capacity for agricultural water and water supply, and reducing flood control functions to prevent flooding. In this case, the river bed rises and flooding becomes more likely to occur.

On the other hand, downstream, the river bed has declined, exposing the bank and foundations, and causing further erosion near the river mouth.

Several methods have been proposed and implemented in the past to remove the sediment deposited at the bottom of the dam.
The most typical method is excavation and dredging, in which the suction head of a sand pump is pushed into the sediment at the bottom of the dam, sucking it up to the surface of the water, and then discharging it. Also,
Other methods have been proposed, such as the closed channel method, the sand removal pipe method, and the siphon method, but these have advantages and disadvantages.

Pump-type excavation and dredging methods are the most widely used and have the advantage of being easy to apply, but on the other hand, a large amount of polluted water (more than 12 times the amount of sand discharged) is blown up, and it is difficult to flush it away downstream. It becomes a new source of pollution.

Normally, a vast sedimentation basin is required for primary treatment, but due to the land conditions, suitable land is often not available, and there are cases where the dam eventually loses its function due to sediment accumulation.

Vertical screw excavators are available to solve the problems of pump-type excavation and dredging systems. That is, a main shaft and a casing surrounding it are installed vertically, and spiral blades are wound around the main shaft.
The lower end serves as an auger head with a protruding tip, and an earth and sand discharge port opens near the upper end. When this main shaft rotates, the head at the lower end digs into the layer of accumulated dirt, scoops up the sand onto the top surface of the spiral blade, and tries to push it upward.

on the other hand. Water slides down the blade surface, passes through the gap between the main shaft blade and the casing, and returns to the water, leaving only the earth and sand transported upwards to reach the discharge port and be discharged.

[Problems that the invention aims to solve] Vertical screw excavators have come to be used not only for excavating and dredging the dam bottoms mentioned above, but also for non-vibration pile drivers, well drilling machines, etc. As the screw rotates, the lifting capacity generated by the frictional force between the conveyed object and the inner surface of the casing is balanced with the frictional force due to the influence of the earth and sand's own weight and fluidity, and the main shaft will no longer rotate. However, the earth and sand solidify together with the screw and just rotate together.
Due to the limited lifting capacity, there is also a limit to the height that can be delivered by the conveyor, making it unsuitable for large-scale dredging.

In addition, the screw machine separates excess moisture and sends out only the solids, but the higher you go, the lower the moisture content and the less fluidity. , it becomes an integral part of Screw and simply rotates together.

In order to solve the above-mentioned problems, the purpose of the present application is to provide a new vertical screw excavator that has excellent lifting capacity and can withstand large-scale, deep dredging work.

[Means for Solving the Problems] In the vertical screw excavator according to the present invention, a casing enclosing the outer edge of a main shaft in which helical blades are circumferentially disposed over almost the entire length can rotate in the opposite direction to the main shaft. The above-mentioned problem was solved by providing a protrusion in the lower part of the casing which widened in a tapered shape and was always close to the blade of the main shaft over the entire area of the casing.

[Function] The function of the screw excavator of the present invention will be explained based on FIG. 1 showing an embodiment.

A helical blade 2 is wound around the main shaft 1 over its entire length, and is erected, with an auger head 3 forming a tip at the lower end and penetrating into the target soil, and an upper end. is connected to the earth and sand discharge port 4, so when this main shaft is rotated by the driving means, the auger head (drill type) breaks up the earth and sand, scoops up the earth and sand onto the blade surface, and begins to transport it upward.

On the other hand, a cylindrical casing 5 having an internal protrusion 6 close to the main shaft blade is mounted coaxially with the main shaft, and this cylindrical casing starts rotating in the opposite direction to the main shaft. The lower part of this cylindrical casing spreads out in a tapered shape, and the blades 2 of the main shaft and the protrusions 6 are always close to each other at any point along the entire length, so that the earth and sand in the area included in the widening casing comes into contact with the blades. It is lifted up by being caught between the protrusions.

The rotation directions of both blades are opposite, and when viewed from another perspective, the earth and sand caught in the space between the blades is
Since the sides are affected by rotational force in the opposite direction, by removing the clamping force and loosening it, it becomes a pushing force and prevents lumps.

For this reason, the present application has the effect of strongly scooping up the earth and sand with a double lifting force, preventing the formation of lumps, and transporting the earth and sand in a loosened state.

[Example] An example of the present application is shown in FIG. 1 (front view) and in FIGS. 2 and 3 as examples of its installation.

FIG. 2 is a front view of the present invention used in a dam reservoir, and FIG. 3 is a plan view thereof, in which a prefabricated floating bridge 7 is set on the water surface of the reservoir using the buoyancy of the foam 8. A pair of steel towers 9, 9 are erected symmetrically and facing each other at desired positions on the floating bridge 7, and are fitted between guide guides on the opposite front surfaces of the steel towers so as to slide vertically up and down. The upper casing 10 is movably suspended.

The upper casing is suspended by a wire rope 12 via a pulley 11 attached to the top of the steel tower together with a set of screw excavators attached to the lower part of the upper casing, and is raised and lowered by the operation of the driving force of a hoist 13. In addition, mooring anchors 14 and mooring wires 15 for fixing the position of the floating bridge are used as shown.

FIG. 1 shows the details of the embodiment of the present invention, in which a supporting member 16 is provided around the lower part of an upper casing 10, and a cylindrical casing 5 is rotatably supported within the supporting member 16 via bearings 17 and 18. Cylindrical casing 5
The upper end of is fitted into the upper casing 10 via a bearing 19. A sealing material 20 is fitted to seal this gap.

A sprocket wheel 21 is attached to the outer periphery of the cylindrical casing 5 and receives driving force from a first drive device 24 via a roller chain 22 and a sprocket 23.

Although a linear protrusion 6 is attached in the axial direction over the entire inner length of the cylindrical portion of the cylindrical casing 5, this may be a helical protrusion.

The cylindrical casing 5 is composed of a cylindrical portion 5A and an enlarged portion 5B that spreads out in a trumpet shape, and a helical blade 25 is attached to the inner wall of the enlarged portion 5B.

In this embodiment, the lower end of the enlarged part 5B is further made into a double structure so that the inner tube 26 has the same shape as the cylindrical part 5A.
B. The helical blade 25, the inner tube 26, and the protrusion 6 provided on the inner wall of the inner tube rotate together, creating a strong lifting force between the reverse rotation of the blades 2 on the main shaft that are close to each other and facing each other. Demonstrate. There are various combinations of the wall and protrusions or blades near the enlarged portion 5B other than this embodiment. For example, the protrusion 6 on the inner wall of the inner tube is linear in the axial direction, but if this is replaced with a helical protrusion in the opposite direction to the blade 2 of the main shaft, an even stronger lifting force can be obtained. The key point is that the earth and sand scooping surfaces that rotate in opposite directions are close to each other over almost the entire length, which relatively strengthens the support and the loosening of the screws to prevent them from rotating together.

On the other hand, to describe a specific example regarding the main shaft 1, the upper end of the shaft is at the top of the upper casing 10 and the bearings 28, 2
9, it is rotatably supported in the vertical direction and receives connection transmission to the second drive device 30.

A stirring material 31 is horizontally mounted on the main shaft facing the earth and sand discharge port 4 provided in the upper casing, and serves to break up the bridging phenomenon in which the discharged earth and sand are blocked. The tip of the main shaft is attached to an auger head 3 with the pointed cutting edge exposed from the casing.

With the configuration outlined above, first, the auger head 3 is positioned on top of the accumulated earth and sand of the dam so that it can dig first, and the second drive device 30 is actuated to drive the main shaft 1.
Rotating and hanging wire rope 1
When 2 is unwound, excavation starts and the device body fits into the excavation hole due to its own weight, and the enlarged part 5 of the cylindrical casing
B. When the inner pipe 26 comes into contact with surrounding earth and sand, the first drive device 24 starts rotating. Earth and sand that has lost its ability to push up due to the reverse rotation of the axis and the periphery are prevented from spinning idly together with the blades.

In this example, the pushing-up ability of the blades 2 of the main shaft and the pushing-up ability of the blades 25 of the enlarged portion 5B of the cylindrical casing are combined and the pushing-up ability increases as it advances toward the upper part of the expansion tube.

The protrusions 6 of the cylindrical portion 5A of the cylindrical casing stop the earth and sand from sliding in the circumferential direction and maintain the earth removal force by pushing up in the axial direction.

[Effects of the invention] As mentioned above, the vertical screw excavator according to the present invention has a much stronger vertical uplifting force for earth and sand compared to the conventional single screw excavator. This has the effect of greatly expanding the scope of application compared to conventional methods, as it is possible to discharge more soil and dirt.

In addition, regarding the generation of polluted water, this method is inherently advantageous compared to pump-type dredging, and has the advantage of not requiring a large sedimentation basin. Moreover, considering the embodiment of the present application, polluted water is generated for a short time until the auger head fits into the excavated hole of earth and sand at the start of excavation, but after the enlarged part 5B fits into the earth and sand layer,
Since it is sealed with earth and sand, it has the unique effect of preventing polluted water from flowing outside.

In addition, if drainage holes are provided in the blade surface of the blade 2 of the main shaft for the earth and sand that is lifted and discharged, the contaminated water initially contained and accompanying the water can be separated and drained on the way and expanded from the sealed cylindrical casing. It flows down to the sediment layer through the pipe.

As described above, the present invention has the excellent effect of efficiently achieving the difficult national land issue of dam dredging and rejuvenation without creating new sources of pollution.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the present invention;
The figure and FIG. 3 are a front view and a plan view showing an overall example of an apparatus to which the present invention is applied. 1... Main shaft, 2... Vane, 3... Auger head, 4... Sediment discharge port, 5... Cylindrical casing,
6... protrusion.

Claims (1)

[Claims for Utility Model Registration] It is supported in the vertical direction and the lower end is an auger head,
The upper end has a main shaft connected to the earth and sand discharge port, and around the outer periphery of the main shaft, spiral blades are arranged around the entire length.
and a vertical screw excavator equipped with a driving means for applying a rotational force to the main shaft, a cylindrical casing that encloses the outer edge of the main shaft and is rotatable in the opposite direction to the main shaft, and a cylindrical casing is mounted on the main shaft, A vertical screw excavator, characterized in that the lower part of the casing widens toward the end in a tapered shape, and is provided with a protrusion that is always close to the blade of the main shaft over the entire area of the casing.