JP2001262966A - Auger screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auger screw capable of easily forming a laterally extended columnar consolidation foundation having a sufficient strength. SOLUTION: This auger screw 1 comprises a rod 2 lifted and rotated by an auger machine, a main spiral wing 2A provided on the circumference of the rod 2 to carry earth and sand along the rod 2 by the rotation of the rod 2, and an auger head 3 provided at the tip of the rod 2. The auger head 3 comprises a consolidation cam 4 having a plurality of cam surfaces 5A and 5B for excavating the ground by the normal rotation of the rod 2 and pressing the earth and sand in the radially outward direction of an excavated hole by the reverse rotation of the rod to consolidate them and auxiliary spiral wings 8A and 8B continued to the cam surfaces 5A and 5B of the consolidation cam 4. The main spiral wing 2A is not continued to the auxiliary spiral wings 8A and 8B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auger screw used by being attached to an earth auger, and more particularly to an auger screw suitable for improving the consolidation of soft ground into a columnar shape.

[0002]

2. Description of the Related Art As one method of consolidating soft ground,
A column consolidation method based on a ground auger for excavation is known. In this construction method, after excavating the ground to a required depth with an earth auger, the earth augmented by the earth auger by reverse rotation is sent to the bottom of the excavation hole with soil and sand added with mountain sand, etc., and consolidated. The earth auger is gradually pulled up from the excavation hole against the consolidation reaction force against the load applied from the working machine, thereby forming a columnar consolidation foundation in the ground.

[0003]

However, in the above method, earth and sand are fed along the longitudinal direction of the earth auger by the reverse rotation of the earth auger. Depending on the soil quality, the soil does not spread so much in the horizontal direction (outward of the drill hole), and the soil quickly compacts in the vertical direction to produce a consolidation reaction, It is difficult to create a columnar consolidation foundation with sufficient spread.

Further, in the above-mentioned construction method, a sufficient load must be applied from the working machine side in order to cause a difference in the degree of consolidation due to a load against the consolidation reaction force for pushing up the earth auger. About 10 tons is required, which is a constraint when developing a small machine in accordance with the circumstances of a narrow residential area in an urban area.

The present invention has been made in view of the above circumstances, and provides an auger screw suitable for ground consolidation that can easily form a columnar consolidation foundation having sufficient strength and having a lateral spread. The purpose is to:

[0006]

Means for Solving the Problems In the present invention, claim 1 is provided.
The auger screw according to the present invention, a rod driven up and down and rotated by an auger machine, a main spiral wing provided on the outer periphery of the rod and transporting earth and sand along the rod by rotation of the rod, and provided at the tip of the rod In the auger screw provided with an auger head, the auger head has a plurality of cam surfaces that excavate the ground by forward rotation of the rod and push earth and sand radially outward of the drilling hole by reverse rotation of the rod to consolidate. And a supplementary spiral blade continuous with a cam surface of the compaction cam, wherein the main spiral blade and the auxiliary spiral blade are not continuous.

According to a second aspect of the present invention, there is provided the auger screw according to the first aspect, wherein the auxiliary spiral blade has a smaller diameter than the main spiral blade.

According to a third aspect of the present invention, there is provided an auger screw comprising: a rod which is lifted and lowered and rotated by an auger machine; a helical wing provided on an outer periphery of the rod for conveying earth and sand along the rod by rotation of the rod; In an auger screw provided with an auger head provided at the tip, the ground is excavated in the auger head by forward rotation of the rod, and soil is pushed outward in the radial direction of the excavation hole by the reverse rotation of the rod to consolidate. A compacted cam having a plurality of cam surfaces is provided, and the spiral blades are provided in a number corresponding to the number of cam surfaces of the compacted cam, and each spiral blade is continuous with each cam surface. And

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a view showing an auger screw according to a first embodiment of the present invention, wherein (a) is a side view of a lower portion of the auger screw, and (b) is a view of the auger head viewed from another direction. FIG. 2C is a front view of the auger head viewed from below, and FIG. 2 is an enlarged side view of a main part of the auger screw of FIG.

An auger screw 1 shown in the drawing has a rod 2 which is moved up and down and rotated by an auger machine (not shown). A main spiral wing 2A for transporting earth and sand along the rod 2 by the rotation of the rod 2 is provided on the outer periphery of the rod 2, and the auger head 3 is detachably attached to the tip of the rod 2 by bolts 20. Attached to. The number of the main spiral blades 2A is one in the illustrated example, but may be plural, for example, two.

A compression cam 4 is provided at the tip of the auger head 3. The consolidation cam 4 excavates the ground by forward rotation of the rod 2 (rotation in the direction of arrow A in FIG. 3C = right rotation) and reverse rotation of the rod 2 [rotation in the direction of arrow B in FIG. ], Two cam surfaces 5A which push the earth and sand radially outward of the borehole [in the direction of arrow F in FIG.
5B.

The consolidation cam 4 has a pair of (two) cam portions 6A and 6B having a substantially semicircular cross section having cam surfaces 5A and 5B each having a contour curve having a substantially circular cross section.
Are formed in a cross-sectional shape eccentric by the same amount of eccentricity in opposite directions to each other. The compacting cam 4 is connected to the rod 2
Has a base circle Dx having an outer diameter substantially the same as the outer diameter of the base circle D.
One end of each cam surface 5A, 5B is in contact with x. Portions connecting the other ends of the cam surfaces 5A and 5B and the base circle Dx are digging portions 7A and 7B for digging the ground. This excavation part 7A,
7B is preferably formed to have a concave cross section in order to improve excavation performance, and may be inclined in the excavation direction [forward rotation direction (direction of arrow A)].

On the upper side of the consolidation cam 4 (on the side of the main spiral blade), the spiral direction is the same as that of the main spiral blade 2A provided on the outer periphery of the rod 2.
Auxiliary spiral wings 8A, 8B are provided continuously on each of the cam surfaces 5A, 5B. By the main spiral blade 2A and the auxiliary spiral blades 8A and 8B, the earth and sand excavated by the excavating parts 7A and 7B are sent upward along the rod 2 when the consolidation cam 4 rotates forward, and the earth and sand is extruded from the rod 2 side when rotating the reverse. They are fed to the cam surfaces 5A and 5B. The compacting cam 4 has a semi-circular shape that is narrowed toward the tip end when viewed from the side.

In order to distribute the earth and sand conveyed by the main spiral blade 2A to the two cam surfaces 5A and 5B substantially uniformly and to supply them in a well-balanced manner, the main spiral blade 2A and the auxiliary spiral blades 8A and 8A,
8B is not continuous but discontinuous. Particularly in the illustrated example, between the main spiral blade 2A and the auxiliary spiral blades 8A and 8B,
A predetermined gap S is formed in the axial direction of the rod 2, and the earth and sand conveyed from one main spiral blade through the gap S is distributed to the two auxiliary spiral blades. It is preferable that the dimension Lb of the gap S in the rod axis direction be equal to or less than の of the dimension La of the auxiliary spiral blades 8A and 8B in the rod axis direction. The tip of the main spiral blade 2A and the auxiliary spiral blades 8A, 8A
Instead of forming a gap S in the rod axis direction between the wing tip of B and the wing tip of the main spiral wing 2A and the wing tips of the auxiliary helical wings 8A and 8B in the circumferential direction, a circumferential direction S is formed between the wing tips. Alternatively, a predetermined gap may be formed. In this case, the dimension Lb of the gap in the rod axis direction is zero.

The outer diameter Da of the compacting cam 4 is
It is preferably equal to or larger than the outer diameter D of A.
The pitch of the auxiliary spiral blades 8A and 8B is preferably smaller than the pitch of the main spiral blade 2A. Further, it is preferable that the auxiliary spiral blades 8A and 8B have a smaller diameter than the main spiral blade 2A. In this case, the auxiliary spiral blade 8
A and 8B have outer diameters gradually reduced upward from the upper ends of the cam surfaces 5A and 5B, and the outer diameter d on the upper end side of the auxiliary spiral blades 8A and 8B is the outer shape D of the main spiral blade 2A or the consolidation cam. 4 is smaller than the outer diameter Da. As a result, a gap Sr is generated between the hole wall (inner wall) of the excavation hole and the auxiliary spiral blades 8A and 8B, and the clearance Sr reduces the radial consolidation of the soil by the auxiliary spiral blades 8A and 8B. Sediment flow from main spiral wing 2A side to consolidation cam 4 side (distribution)
Can be better.

In FIG. 2, reference numeral 19 denotes a chip made of a cemented carbide or the like provided on the ridge of the excavated portions 7A and 7B of the consolidation cam 4. The tip 19 is divided into a plurality of parts and attached by welding, bolts, etc., so that they can be replaced when worn. Chip 1 replaceable in this way
By providing 9, the overall durability can be improved and the excavation performance can be maintained.

Next, the operation of the auger screw 1 having the above configuration will be described. When excavating the ground, the auger screw 1 is rotated forward (right rotation = rotated in the direction of arrow A), and excavated from the tip side into the ground to excavate the ground.
In this excavation step, the ground is excavated by the excavated portions 7A and 7B of the consolidation cam 4, and the excavated soil (ground soil) is transported upward by the spiral wings 8A, 8B, 2A and 2B and is carried out to the ground. .

When the ground has been excavated to the required depth, the rotation direction of the auger machine is switched and the auger screw 1 is removed.
Is rotated in the reverse direction (rightward rotation = rotation in the direction of arrow B). At this time, earth and sand (mixed soil) obtained by adding a soil improvement material, for example, mountain sand, cement, etc., to the earth carried or dug up to the ground is put into the excavation hole from the opening.

The injected earth and sand is conveyed downward by the main spiral blade 2A, and is further transferred to the auxiliary spiral blade 8 of the auger head 3.
A and 8B feed the cam surfaces 5A and 5B, respectively. In this case, the earth and sand conveyed by the main spiral blade 2A is substantially equally distributed to each of the two auxiliary spiral blades 8A and 8B through the gap S between the main spiral blade 2A and the auxiliary spiral blades 8A and 8B. The two cam surfaces 5A and 5B are fed in a well-balanced manner. The diameter d of the upper end side of the auxiliary spiral blades 8A, 8B is equal to the outer diameter D, Da of the main spiral blade 2A or the consolidation cam 4.
By being formed slightly smaller than that, the earth and sand are prevented from being radially consolidated by the auxiliary spiral blades 8A and 8B, and the earth and sand is smoothly supplied from the main spiral blade side to the consolidated cam side. Then, the soil is pushed in the lateral direction (outward in the radial direction of the excavation hole, in the direction of arrow F) by the two cam surfaces 5A and 5B and is compacted. The earth and sand is also sent to the bottom of the hole on the tip side along the outer periphery of the consolidation cam 4 and is consolidated by the tip sides of the cam surfaces 5A and 5B.

In this case, the consolidation cam 4 receives a consolidation reaction force from the bottom of the hole, but receives more consolidation reaction force from the hole wall side (in the radial direction of the drilling hole). The auger screw 1 is not undesirably pushed up unlike the case described above. For this reason, it is not necessary to apply a load against the consolidation reaction force to the auger screw 1, so that the size of the auger machine can be reduced without being forced to increase in size. The degree of compaction can be inferred by the torque applied to the auger machine, etc., and by gradually pulling up the auger screw 1 while maintaining the desired compaction density,
Create a column-shaped consolidation foundation.

As described above, according to the auger screw 1, the rod 2 which is raised and lowered and rotated by the auger machine, and the spiral which is provided on the outer periphery of the rod 2 and conveys the earth and sand along the rod 2 by the rotation of the rod 2 Wing 2A, 2
B, and an auger head 3 provided at the tip of the rod 2. The auger head 3 excavates the ground by the forward rotation of the rod 2, and removes the earth and sand by the reverse rotation of the rod 2 radially outward of the excavation hole. A consolidation cam 4 having a plurality of cam surfaces 5A, 5B to be pressed and consolidated is provided, and the spiral blades 2A, 2B are provided with a number of strips corresponding to the number of cam surfaces 5A, 5B of the consolidation cam 4 (in the present embodiment, 2), and each spiral blade 2A, 2
Since B is continuous with each of the cam surfaces 5A and 5B, the earth and sand can be efficiently fed into each of the cam surfaces 5A and 5B, and a columnar consolidation foundation having sufficient strength having a lateral spread can be easily and efficiently formed. It can be formed well.

When the ground is extremely soft, such as mud, the auger screw 1 is rotated while the consolidating cam 4 is rotated in the consolidating direction (reverse rotation direction) without excavating the ground as described above. Is inserted directly into the ground (the ground improvement material is not supplied in this step), and when the ground improvement material is inserted to a predetermined depth, the ground improvement material, for example, mountain sand is supplied to start consolidation. A columnar consolidation foundation may be created by using the method described above.

FIGS. 3A and 3B are views showing an auger screw according to a second embodiment of the present invention. FIG. 3A is a side view of a lower portion of the auger screw, and FIG. 3B is a view of the auger head viewed from another direction. FIG. 4C is a front view of the auger head viewed from below, and FIG. 4 is an enlarged side view of a main part of the auger screw of FIG. In the present embodiment, the same parts as those in the above embodiment are denoted by the same reference numerals.

An auger screw 1 shown in the drawing has a rod 2 which is moved up and down and rotated by an auger machine (not shown). Two spiral wings (main spiral wings) 2A and 2B for transporting earth and sand along the rod 2 by rotation of the rod 2 are provided on the outer periphery of the rod 2, and at the tip of the rod 2, Auger head 3 with bolt 20
Is detachably attached.

At the tip of the auger head 3, a compression cam 4 is provided. The consolidation cam 4 excavates the ground by forward rotation of the rod 2 (rotation in the direction of arrow A in FIG. 3C = right rotation) and reverse rotation of the rod 2 [rotation in the direction of arrow B in FIG. ], Two cam surfaces 5A which push the earth and sand radially outward of the borehole [in the direction of arrow F in FIG.
5B.

The consolidation cam 4 faces a pair of cam portions 6A and 6B having a substantially semicircular cross section having cam surfaces 5A and 5B each having a cam surface 5A and 5B having a substantially arcuate cross section. It is formed in the cross-sectional shape decentered by the same eccentric amount. Further, the consolidation cam 4 has a base circle Dx having substantially the same outer diameter as the outer diameter of the rod 2, and one end of each of the cam surfaces 5A and 5B is in contact with the base circle Dx. Cam surface 5A, 5B
Excavation parts 7A and 7B for excavating the ground are connected to the other end of the base and the base circle Dx. The excavation portions 7A and 7B are preferably formed in a concave cross section in order to improve excavation performance, and may be inclined in the excavation direction [forward rotation direction (direction of arrow A)].

On the upper side of the compression cam 4, two spiral blades (auxiliary spiral blades) 8A and 8B continuous with the spiral blades 2A and 2B provided on the outer periphery of the rod 2 are connected to the respective cam surfaces 5A and 5B. It is provided. These spiral blades 2A, 2B, 8A, 8
B, the excavating portions 7A, 7
The earth and sand excavated at B is sent upward along the rod 2, and the earth and sand is sent from the rod 2 side to the cam surfaces 5A and 5B during the reverse rotation. The compacting cam 4 has a semi-circular shape that becomes narrower toward the tip end when viewed from the side. A tip 19 made of a cemented carbide or the like is provided on a ridge line portion of the excavated portions 17A and 17B of the consolidation cam 14.

Next, the operation of the auger screw 1 having the above configuration will be described. When excavating the ground, the auger screw 1 is rotated forward (right rotation = rotated in the direction of arrow A), and the excavation is performed by excavating the ground from the tip side.
In this excavation step, the ground is excavated by the excavated portions 7A and 7B of the consolidation cam 4, and the excavated soil (ground soil) is transported upward by the spiral wings 8A, 8B, 2A and 2B and is carried out to the ground. .

When the ground has been excavated to the required depth, the rotation direction of the auger machine is switched and the auger screw 1 is removed.
Is rotated in the reverse direction (rightward rotation = rotation in the direction of arrow B). At this time, earth and sand (mixed soil) obtained by adding a soil improvement material, for example, mountain sand, cement, etc., to the earth carried or dug up to the ground is put into the excavation hole from the opening.

The injected earth and sand are two spiral blades 2A, 2
B, and is further fed into the respective cam surfaces 5A, 5B by the spiral blades 8A, 8B of the auger head 3, respectively, and is laterally moved by both the cam surfaces 5A, 5B (radially outward of the drill hole, arrow F direction). ) And is compacted. The earth and sand is also sent to the bottom of the hole on the tip side along the outer periphery of the consolidation cam 4 and is consolidated by the tip sides of the cam surfaces 5A and 5B.

In this case, the consolidation cam 4 receives the consolidation reaction force from the bottom of the hole, but receives more consolidation reaction force from the hole wall side (radial direction of the excavation hole). The auger screw 1 is not undesirably pushed up unlike the case described above. For this reason, it is not necessary to apply a load against the consolidation reaction force to the auger screw 1, so that the size of the auger machine can be reduced without being forced to increase in size. The degree of compaction can be inferred by the torque applied to the auger machine, etc., and by gradually pulling up the auger screw 1 while maintaining the desired compaction density,
Create a column-shaped consolidation foundation.

As described above, according to the auger screw 1, the rod 2, which is raised and lowered and rotated by the auger machine, and which is provided on the outer periphery of the rod 2 and conveys earth and sand along the rod 2 by the rotation of the rod 2. Spiral wing 2A
And an auger screw 1 provided with an auger head 3 provided at the tip of the rod 2. In the auger head 3, the ground is excavated by forward rotation of the rod 2, and earth and sand is excavated by reverse rotation of the rod. And a plurality of auxiliary helical blades 8A and 8B continuous with the cam surfaces 5A and 5B of the consolidation cam 4 are provided. Since the spiral blade 2A and the auxiliary spiral blades 8A, 8B are continuous, each cam surface 5A,
The earth and sand can be independently fed into 5B, and a columnar consolidated foundation having sufficient strength and having a lateral spread can be easily and efficiently formed. In addition, since the auxiliary spiral blades 8A and 8B are formed to have a smaller diameter than the main spiral blade 2A, it is possible to improve the flow and distribution of the earth and sand from the main spiral blade 2A to the consolidation cam 4.

FIG. 5 shows a modification of the auger screw. This auger screw 1 is provided with one or more rows of spike tips 29 made of cemented carbide or the like at the ridge portions of the excavated portions 7A and 7B of the consolidation cam 4 so that the spike tips 29 are also suitable for concrete excavation. Has become.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments, and various design changes and the like can be made without departing from the gist of the present invention. Is possible. For example, in the above-described embodiment, a compacted cam having two cam surfaces is illustrated, but three or more cam surfaces may be provided. In addition, the auger head may be attached to the tip of the rod with a pin other than the bolt.

[0036]

According to the present invention as described above, the following effects can be obtained.

(1) According to the auger screw according to the first aspect, the rod which is lifted and lowered and rotated by the auger machine, and the main spiral which is provided on the outer periphery of the rod and conveys earth and sand along the rod by rotation of the rod. In an auger screw provided with a wing and an auger head provided at the tip of the rod, the auger head excavates the ground by forward rotation of the rod and removes earth and sand by a reverse rotation of the rod in a radial direction of the drill hole. And a supplementary spiral blade continuous with the cam surface of the compaction cam is provided, and the main spiral blade and the auxiliary spiral blade are not continuous. The soil can be sent efficiently and in a well-balanced manner to the surface, and a columnar consolidated foundation with sufficient strength that spreads in the lateral direction can be easily and efficiently formed. .

(2) According to the auger screw of the second aspect, since the auxiliary spiral wing is formed to have a smaller diameter than the main spiral wing, the flow of earth and sand from the main spiral wing toward the consolidation cam is improved. be able to.

(3) According to the auger screw according to the third aspect, a rod which is lifted and lowered and rotated by the auger machine, and a spiral wing provided on the outer periphery of the rod and conveys earth and sand along the rod by rotation of the rod. And an auger screw provided with an auger head provided at the tip of a rod, wherein the auger head excavates the ground by forward rotation of the rod and pushes earth and sand radially outward of the borehole by reverse rotation of the rod. A plurality of consolidation cams having a plurality of cam surfaces for consolidation are provided, and the spiral blades are provided in a number corresponding to the number of cam surfaces of the consolidation cams, and each spiral blade is continuous with each cam surface. In addition, earth and sand can be efficiently fed into each cam surface, and a columnar consolidation foundation having sufficient strength and having a lateral spread can be easily and efficiently formed.

[Brief description of the drawings]

FIG. 1 is a view showing an auger screw according to a first embodiment of the present invention, wherein (a) is a side view of a lower portion of the auger screw, and (b) is a side view of the auger head viewed from another direction. (C) is a front view of the auger head viewed from below.

FIG. 2 is an enlarged side view of a main part of the auger screw of FIG.

FIG. 3 is a view showing an auger screw according to a second embodiment of the present invention, wherein (a) is a side view of a lower portion of the auger screw, and (b) is a side view of the auger head viewed from another direction. (C) is a front view of the auger head viewed from below.

FIG. 4 is an enlarged side view of a main part of the auger screw of FIG. 3;

FIG. 5 is an enlarged side view of a main part showing a modified example of the auger screw.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Auger screw 2 Rod 2A Main spiral blade 3 Auger head 4 Consolidation cam 5A, 5B Cam surface 8A, 8B Auxiliary spiral blade

Claims (3)

[Claims] 1. A rod driven up and down and rotated by an auger machine, a main spiral wing provided on an outer periphery of the rod and transporting earth and sand along the rod by rotation of the rod.
An auger screw provided with an auger head provided at the tip of the rod, wherein the auger head excavates the ground by forward rotation of the rod and pushes earth and sand radially outward of the excavation hole by reverse rotation of the rod. An auger screw wherein a consolidation cam having a plurality of cam surfaces for consolidation is provided, and auxiliary spiral blades continuous with the cam surface of the consolidation cam are provided, and the main spiral blade and the auxiliary spiral blade are not continuous. . 2. The auger screw according to claim 1, wherein the auxiliary spiral blade has a smaller diameter than the main spiral blade. 3. A rod driven up and down and rotated by an auger machine, a helical wing provided on the outer periphery of the rod to convey earth and sand along the rod by rotation of the rod, and an auger head provided at a tip of the rod. In the auger screw provided with the auger head, the auger head had a plurality of cam surfaces for excavating the ground by forward rotation of the rod and pushing earth and sand radially outward of the drill hole by reverse rotation of the rod to consolidate. A consolidation cam is provided, and the spiral wings are provided in a number corresponding to the number of cam surfaces of the consolidation cam,
An auger screw wherein each spiral blade is continuous with each cam surface.