JPH0632982Y2 - Air shutter for casing for sand piles - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention relates to an air shutter for a casing for sand pile construction,
More specifically, when a casing used for inserting a sand pile formed by filling sand into a water-permeable bag is pulled out from the ground, an air pressure is applied to hold down the sand pile. It is related to an air shutter that enables to.

[Conventional technology]

As a method for improving soft and viscous ground, a packed drain method has been proposed in which sand is filled in a bag having a long water permeability to form sand piles and the sand piles are inserted into the ground.

In the packed drain method, as shown in FIG. 4, the cylindrical casing 3 held by the leader 2 of the pile driving mechanism 1 is driven into the ground by the hammer 4, and when the driving of the casing 3 is completed, a small amount of sand is added to the tip. The water-permeable bag 5 containing the above is put into the casing 3, and the bag 5 is filled with sand 6 by utilizing the vibration of the hammer 4, and the sand 6 is filled up to the upper end of the bag 5 to form the sand pile 7. Once formed, close the top of casing 3,
When pressure air is supplied into the casing 3 from above to apply a pressing force to the upper end of the sand pile 7, and the casing 3 is pulled out while vibrating in this state, the upper end is exposed to the ground as shown in FIG. The sand pile 7 will immediately start dehydration so as to reduce the excessive pore water pressure in the ground.

By the way, in the sand pile construction method as described above, the sand is charged from the upper end of the casing 3 and the sand pile 7 is prevented from being pulled up when the sand 3 is pulled out.
Since it is necessary to apply an air pressure to the inner upper portion, an opening / closing structure must be adopted at the upper end of the casing 3.

Conventionally, as shown in FIG. 6, the opening / closing structure of the upper end of the casing has an upper lid 8 on the upper end of the casing 3 and a pivot 1 of a hinge 9.
It has a structure in which it is pivotally mounted so as to be able to rotate up and down around 0, and the upper lid 8 is locked to the casing 3 by operating the handle 11.

[Problems to be solved by the device]

However, in the structure in which the upper lid 8 is opened and closed by the operation of the handle 11, when the air pressure remains in the casing 3, the air pressure causes the upper lid 8 to be rapidly released when released, and the upper lid 3 collides with the worker. There is a risk of injury.

An object of the present invention is to provide an air shutter for a casing for sand pile construction, in which the operation of releasing the upper end of the casing can be performed safely and which is excellent in airtightness when closed.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention fixes a cylindrical case to the upper end of the casing so that the axes of the casing are orthogonal to each other, and forms a circular opening in the upper and lower parts of the casing that matches the inner diameter of the casing. A shutter member that is provided coaxially with and is rotatably operated to open and close the upper opening from the outside of the case is housed in the case. The circular plate, a pair of arms that are provided on both sides of the back surface of the circular plate so as to face each other, and the tips of which are rotatably supported by the both side plates on the axis of the case, and the surface of the circular plate that is in sliding contact with the inner surface of the case. And a flexible seal plate stretched over the outer circumference of the seal plate, and a free portion protruding outward from the outer diameter of the circular plate is provided on the outer periphery of the seal plate. Those were.

[Action]

When pressure air is supplied into the casing with the upper opening of the case closed by the seal plate, the free part protruding from the circular plate on the outer periphery of the seal plate receives the pressure and sticks to the inner surface of the case, opening the upper opening. Since the casing is hermetically sealed, the casing maintains the airtight state inside the case.

To release the upper end of the casing, the shutter member can be rotated from the outside of the case, and the seal plate gradually opens the upper opening of the case while sliding on the inner surface of the case. Even if the pressure air remains, it can be safely released. When the shutter member is in the open position, it opens just above the inner diameter of the casing, so that the upper end of the casing can be fully opened.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings.

As shown in the figure, the cylindrical case 21 provided at the upper end of the casing 3 is formed to have a diameter larger than the inner diameter of the casing 3, and the axial center is arranged so as to be orthogonal to the axial center of the casing 3. Circular openings 22 and 23 corresponding to the inner diameter of the casing 3 are provided at positions on the axial center of the casing 3 above and below the peripheral wall, and a cylindrical wall 24 is provided so as to project around the upper opening 22.

The shutter member 25 housed in the case 21 is provided with a pair of arms 27, 27 facing each other on both sides of the back surface of a circular plate 26, and a seal plate 28 made of a flexible material such as rubber on the surface of the circular plate 26. It is constructed by stretching.

The circular plate 26 is formed in an arc shape having a diameter corresponding to the upper opening 22 of the case 21 and extending along the inner surface of the peripheral wall of the case 21, and the pair of arms 27, 27 are provided on both ends of the circular plate 26 at their tips. Shafts 29 and 30 are rotatably supported by both side end walls 31 and 32 of the case 21.

The shafts 29 and 30 on both sides are supported at a position on the axial center of the case 21, so that the shutter member 25 is moved to the case 21.
When the circular plate 26 is located at the uppermost position, the upper opening 22 is rotatable about the axis of the upper opening 22 as shown in FIG.
On the other hand, immediately below it, it is arranged coaxially, and the arms 27, 27 on both sides are located outside the area just above the inner diameter range of the casing 3.

The seal plate 28 is attached so as to be in sliding contact with the inner peripheral surface of the peripheral wall of the case 21, and an annular free portion 33 projecting outward from the outer diameter of the circular plate 26 is provided on the outer periphery of the seal plate 28.

The means for rotating the shutter member 25 may be such that one shaft 30 is projected to the outside of the case 21 and is rotated within a range of 90 ° manually by a handle or by a driving machine.

Further, an air pipe 34 for supplying pressurized air to the inside is connected to the upper end of the casing 3.

The air shutter of this invention has the above-mentioned configuration,
At the time of constructing the sand pile, as shown by the alternate long and short dash line in FIG. 2, the shutter member 25 is made to stand by at a position where the circular plate 26 faces sideways, and the upper opening 22 is opened.

At this time, since the shutter member 25 is in the lateral direction, the circular plate 26 and the seal plate 28 are located on the side portion inside the case 21, and the projecting portion is provided between the portion just above the inner diameter range of the casing 3 and the upper opening 22. Since there is no sand pile, construction of sand piles can be done without any problems.

Next, in the process of pulling out the casing 3 after forming the sand pile, as shown in the drawing, the shutter member 25 is rotated by 90 ° so that the circular plate 26 is positioned immediately below the opening 22 and the opening 22 is formed by the seal plate 28. In this state, pressure air is supplied to the casing 3 by the air pipe 34, and the casing 3 is pulled out from the ground while pressing the sand pile with the pressure of the air.

At this time, air pressure acts on the free portion 33 of the seal plate 28, and the free portion 33 comes into close contact with the inner peripheral surface of the casing 3 to form an airtight seal portion, improving the airtightness of the portion that closes the opening 22. Air pressure can be applied to the sand pile.

Further, when the shutter member 25 is rotated to the open position, the seal plate 28 slides on the inner surface of the case 21,
Since the opening 22 is gradually opened, air can be gradually released even when air pressure remains in the casing 3, and the upper end of the casing 3 can be safely opened.

〔effect〕

As described above, according to the present invention, the shutter member is rotatably provided in the cylindrical case provided so as to be orthogonal to the upper end of the casing, and the circular plate of the shutter member is provided with the seal plate slidably contacting the case. Therefore, it is possible to open and close the upper end of the casing for constructing a sand pile by filling sand in a water-permeable bag by rotating the shutter member.
When opened, the upper end of the casing can be fully opened, so bag insertion and sand filling can be performed without problems.

Also, since a free area is provided around the seal plate,
When pressing air is supplied into the casing and the sand pile is pushed and the casing is pulled out, the loose part receives air pressure and makes close contact with the inner surface of the case, and the upper end opening of the casing can be reliably sealed. Pressing efficiency of sand pile by air is improved,
The casing can be pulled out smoothly.

Further, when the upper end of the casing is opened, the residual air can be released by gradually opening the upper opening by rotating the shutter member, so that the operation of opening the upper end of the casing can be performed safely.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an air shutter according to the present invention,
FIG. 2 is a vertical side view of the same, FIG. 3 is an exploded perspective view of the same, FIG. 4 is an explanatory view at the time of sand pile construction, FIG. 5 is a cross-sectional view of the sand pile, and FIG. 6 is a conventional casing structure. It is a front view shown. 3 ... Casing, 21 ... Case, 22, 23 ... Opening, 25 ... Shutter member, 26 ... Circular plate,
27 ... Arm, 28 ... Seal plate, 33 ... Free part.

Claims (1)

[Scope of utility model registration request] 1. A cylindrical case is fixed to the upper end of the casing so that the axes thereof are orthogonal to each other, and circular openings matching the inner diameter of the casing are provided in the upper and lower parts of the case coaxially with the casing. A shutter member that rotates to open and close the upper opening from the outside of the case is housed inside, and the shutter member has an arc-shaped circular plate with a diameter matching the upper opening and extending along the inner surface of the case, and the back surface of the circular plate. A pair of arms that are opposed to each other and whose ends are rotatably supported by both side plates on the axis of the case, and a flexible seal stretched on the surface of the circular plate so as to be in sliding contact with the inner surface of the case. An air shutter for a casing for sand pile construction, which is formed with a plate, and has a free portion protruding outside the outer diameter of the circular plate on the outer periphery of the seal plate.