JPH0226988Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications The present invention relates to improvement of soil improvement equipment.

Conventional technology As a conventional ground improvement device, the ground is excavated using a digging blade installed at the lower end of a rotating shaft, and a stirring blade installed at the lower end of the rotating shaft is used to excavate soil from the excavated ground and supply liquid into the ground. A type of mixing and stirring method has been proposed.

Problems to be Solved by the Invention However, in the conventional soil improvement device described above, the mixing and stirring effect is simply achieved by the horizontal rotation of the stirring blades, which inevitably causes variations in the mixing, making it difficult to improve the soil. There was a problem that it could easily become non-uniform.

This type of non-uniformity in ground improvement can be caused by, for example, having an auxiliary stirring member rotated by a separate drive system in addition to the main stirring blade, and rotating this auxiliary stirring member in the opposite direction to the main blade. Although this problem can be solved to some extent by doing so, it requires a plurality of drive systems, which complicates the equipment and operation, which is not a preferable solution.

The present invention was made with the aim of eliminating these conventional problems.

Means for Solving the Problems The present invention uses a rotary shaft that is integrally equipped with a digging blade at the lower end and a stirring blade that extends horizontally slightly above the digging blade, while rotating in the ground. In a ground improvement device that mixes and stirs the excavated ground soil and the liquid agent supplied in the ground soil by inserting the stirring blade, a radially arranged part is placed slightly closer to the tip than the middle of the stirring blade in the extending direction. A ground improvement characterized by comprising an impeller having a plurality of stirring blades that is horizontal and rotatable, and the effective radius of the impeller is set to be slightly larger than the distance between its center of rotation and the tip of the stirring blade. Related to equipment.

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

In the ground improvement device according to the present invention, the main body of the device includes a rotating shaft 1 that is rotated by an appropriate driver (not shown) and a lower end portion of the rotating shaft 1, as in conventional devices of this type. A horizontally extending excavation blade 2 is provided integrally with the rotary shaft 1 and excavates the ground when the rotary shaft 1 descends, and a horizontally extending excavation blade 2 is further provided integrally with the lower part of the rotary shaft 1 and excavates the ground when the rotary shaft 1 ascends. and a horizontally extending stirring blade 3 that mixes and stirs the liquid agent supplied in the ground, and the liquid agent for soil improvement is
From the liquid passage 11 of the rotating shaft 1, the shaft 1 and the excavating blade 2
It is configured such that it is injected into the ground through a nozzle (not shown) provided on the stirring blade 3 and the like.

In this type of soil improvement device, the present invention has a plurality of stirring blades 4 arranged radially in a portion slightly closer to the tip than the middle of the stirring blade 3 in the extending direction.
The impeller 4 is horizontally and freely rotatable, and the effective radius of the impeller 4 is set slightly larger than the distance between its center of rotation and the tip of the stirring blade 3.

According to the ground improvement device according to the present invention, when the stirring blade 3 is rotated in the excavated ground using the rotating shaft 1, the impeller 4 attached to the blade 3 rotates in the opposite direction on the blade 3.

5A to 5C are diagrams explaining the principle of reverse rotation of the impeller 4, and FIG. 5A shows the four stirring blades 4 of the impeller 4.
1, 42... shows a situation where the tip of the stirring blade 41 is frictionally engaged with the hard ground surface b around the excavated soil a (blank area in the figure).

In the state shown in FIG. 5, when the rotating shaft 1 rotates the stirring blade 3 integrated with the shaft 1 in a clockwise direction, as the blade 3 rotates, the stirring blade 41 moves on the hard ground surface b.
It bites into the inside of the hole while maintaining frictional engagement with the hole, and the depth of the bite is as shown in Figure 5B.
That is, it reaches its maximum when the central axes of the blades 3 and blades 41 coincide, and after that it gradually becomes shallower until it deviates from the hard ground surface b in the state shown in FIG. 5C.

When looking at the relationship between the stirring blade 3 and the impeller 4, the impeller 4 is rotated 90 degrees on the blade 3 in the opposite direction.

As shown in FIG. 5C, the preceding stirring blade 4
At the point when the stirring blade 1 is removed from the hard ground surface b, the following stirring blade 42 starts to engage in friction with the hard ground surface b, and eventually bites into it, and by repeating this operation, the impeller 4 becomes the stirring blade. 3 and rotated in the opposite direction.

Therefore, in the present invention, when the rotating shaft 1 descends, the ground is excavated by the excavating blade 2 at the lower end thereof,
When rising, the stirring blade 3 at the bottom of the rotating shaft 1 and the blade 3
The ground soil excavated by the impeller 4 attached to the
The purpose of soil improvement can be achieved by mixing and stirring the liquid agent supplied into the ground, and in this case, the mixing and stirring of the ground soil and the liquid agent is carried out by using stirring blades 3 and impellers 4 that rotate in different directions. Since the mixing is carried out using two types of stirring members, the mixing and stirring effect is improved, and uneven mixing and stirring, as well as non-uniformity in ground improvement, can be eliminated.

Further, since the impeller 4 is rotated using the rotary shaft 1 as a drive source, only one drive system is required, and such improvement in mixing and stirring effects can be easily achieved in terms of equipment and operation.

In the present invention, the number of stirring blades 41, 42... provided in the impeller 4 is not particularly limited as long as it is a plurality of blades, but if the number is small, the rotation of the impeller 4 tends to be uncertain, and If the number is too large, the rotation will be stabilized, but there is a risk that the impeller 4 and the ground will rotate together, so 3 to 8 pieces, especially 4 to 6 pieces, is appropriate.

The impeller 4 is usually provided on both sides of the upper and lower ends of the stirring blade 3 as shown in the figure, but in some cases, the impeller 4 may be provided on either the upper or lower ends.

When the impeller 4 is provided at both the upper and lower ends of the stirring blade 3,
The upper and lower impellers 4, 4 may be integrated or may be separated so that they can rotate independently. When the upper and lower stirring blades are integrated, it is preferable to arrange the upper and lower stirring blades so as to be shifted by half a pitch as shown in FIG.

The effective radius of the impeller 4, that is, each stirring blade 41, 4
2... is determined by the length between the rotation center 4a of the impeller 4 and the stirring blade 3 in order to obtain a frictional engagement with the hard ground surface b.
It needs to be slightly larger than the distance connecting the tips 3a of The most ideal size is such that the trailing blade 42 starts frictional engagement with the hard ground surface b. The impeller 4 always maintains a tendency to rotate in the opposite direction to the stirring blade 3 due to the difference in resistance between the inner and outer sides of the rotation center 4a. Therefore, even if the dimensional difference between the stirring blades is somewhat smaller than the ideal dimensional difference mentioned above, the reverse rotation tendency of the impeller 4 can ensure the frictional engagement between the blade tips and the hard ground surface b, and especially No problem. On the other hand, if the dimensional difference exceeds the ideal dimensional difference, the depth of penetration into the hard ground surface b will increase, and a correspondingly large load will be applied to the impeller 4. Therefore, it is better to keep such a positive dimensional difference as small as possible. good.

Effects As described above, according to the present invention, it is possible to easily improve the mixing and stirring performance of the soil improvement equipment in terms of equipment and operation, and to use this type of soil improvement equipment with light equipment, low cost, and high performance. It has the features that it can provide.

[Brief explanation of the drawing]

FIG. 1 is a front view of main parts showing an embodiment of the present invention;
2 is a plan view of FIG. 1, FIG. 3 is a plan view of main parts showing another embodiment of the present invention, FIG. 4 is a plan view of FIG. 3, and FIGS. It is a diagram explaining the principle of reverse rotation of a car. In the figure, 1 is a rotating shaft, 2 is a digging blade, 3 is a stirring blade, 4 is an impeller, and 41, 42, . . . are stirring blades.

Claims (1)

[Scope of utility model registration request] A rotary shaft that is integrally equipped with an excavation blade at the lower end and a stirring blade that extends horizontally slightly above the excavation blade is inserted into the ground while rotating, and the excavated soil and the ground soil are removed. In a soil improvement device that mixes and stirs liquid supplied internally, an impeller having a plurality of stirring blades arranged radially is installed at a portion slightly closer to the tip than the middle of the stirring blade in the extending direction. A ground improvement device characterized in that the impeller is rotatable and the effective radius of the impeller is set slightly larger than the distance between the center of rotation of the impeller and the tip of the stirring blade.