JPH08144261A - Stirring device for soil improvement - Google Patents

Abstract

PURPOSE: To prevent the sedimentation and consolidation of an improved material to the passage thereof when a stirring shaft is pulled out. CONSTITUTION: A shaft body 6 mounting up and down three stages of stirring wings 7, 8 and 9 is divided into an upper shaft 10 and a lower shaft 11, and as improved material passages to which an improved material together with compressed air is supplied, an upper passage 17 and a lower passage 18 are provided in the upper shaft 10 and lower passage 11 respectively. When a stirring shaft 4 is pulled out, the passages 17 and 18 are cut off by a claw clutch mechanism C as a passage opening and closing device to block the inflow of the improved material and compressed air to the lower passage 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a ground improving method which is attached to the lower end of a stirring shaft in a construction method in which a powdery and granular improving material is sent together with compressed air into soft ground to stir and mix to strengthen the ground. The present invention relates to a stirring device.

[0002]

2. Description of the Related Art This agitator comprises a plurality of upper and lower stages of agitating blades provided on the outer periphery of a shaft body having an improving material passage in the axial center part thereof. Each of the discharge ports is provided in communication with the improvement material passage.

In the ground improvement method using this agitator, the improver is sent together with compressed air into the improver passage of the agitator through the hollow part of the agitator, and (I) when the agitator penetrates, the soil from the lower discharge port is discharged. In order to prevent the back flow of the compressed air, only compressed air is ejected from the same outlet, (II) When the predetermined depth is reached, the improving material is ejected from the lower outlet, and the mixture is stirred and mixed by a stirring blade to perform tip treatment, (III) After this, the stirring shaft is reversed to move to the drawing process, the lower discharge port is closed, and the improving material is sprayed from the upper discharge port while stirring.
The improved columns will be created by mixing them.

[0004]

However, according to the conventional stirring device, in the drawing process of the stirring shaft, the improving material is deposited in the improving material passage between the upper stirring blade and the lower stirring blade, and compressed air is used. It is compressed and becomes a solidified state.

In this case, in an agitator having a small number of agitating blades (the distance between the upper and lower agitating blades is short), the amount of the deposit improving material is also small, and therefore the penetration rotation is switched to the compressed air from the lower outlet. It is possible to discharge the sediment improving agent into the soil by blowing it out.However, especially in a stirrer with more than three stirring blades to increase the stirring efficiency, the resistance of the sediment improving agent is large and the air pressure is high. It cannot be discharged by itself.

Therefore, the deposit improving material must be removed manually by a human, and this cleaning operation causes a loss of construction time and a reduction in construction efficiency.

Therefore, the present invention provides a ground improvement agitator capable of preventing the improvement material from being clogged during the agitation shaft drawing process.

[0008]

According to a first aspect of the present invention, a plurality of upper and lower stages of stirring blades are mounted at intervals on the outer periphery of a shaft body connected to the lower end of the stirring shaft, and the shaft body is provided with an improved material. In the ground improvement agitator, in which the improvement material passage into which the air is sent together with the compressed air, and the improvement material discharge ports communicating with the improvement material passage are provided in both the upper and lower stirring blades, respectively. Divided into an upper passage and a lower passage with an intermediate point between the blade and the lower stirring blade as a boundary,
Further, the upper passage and the lower passage are provided with a passage opening / closing means that makes them communicate with each other when the stirring shaft penetrates and blocks them when the stirring shaft is pulled out.

According to a second aspect of the present invention, in the structure of the first aspect, as the passage opening / closing means, the shaft body is axially divided into an upper shaft and a lower shaft with a joint between the upper passage and the lower passage as a boundary. The lower shaft is connected to the upper shaft so as to be rotatable relative to the upper shaft within a certain angle range, and the upper passage and the lower passage are connected and disconnected by the relative rotation of the upper shaft and the lower shaft. The opening is provided in a state of being displaced in the radial direction with respect to the axis of the shaft.

According to a third aspect of the present invention, in the structure of the first aspect, an opening / closing valve that opens and closes by remote control is provided between the upper passage and the lower passage as the passage opening / closing means.

According to a fourth aspect of the present invention, in any one of the first to third aspects, an auxiliary passage through which compressed air is passed is provided in the shaft body along the upper passage, and the auxiliary passage is provided in the lower passage. On the other hand, an auxiliary passage opening / closing means is provided which is blocked when the stirring shaft penetrates and communicates with the stirring shaft when withdrawn.

According to a fifth aspect of the present invention, in the structure of the second aspect, an auxiliary passage through which compressed air is passed is provided in the upper shaft along the upper passage and by the relative rotation of the upper shaft and the lower shaft. The opening on the seam side is provided so as to be displaced in the radial direction with respect to the axial center of the shaft and in the circumferential direction with respect to the upper passage so as to communicate with the lower passage at the time of pulling out.

[0013]

According to the above construction, when the improving material is discharged from the upper discharge port (when the stirring shaft is pulled out), the lower passage is blocked from the upper passage by the passage opening / closing means, and the improving material and the compression material to the lower passage are compressed. Since the inflow of air is blocked, it is possible to prevent the improvement material from being deposited and solidified in the passage.

In this case, according to the second aspect of the invention, the upper passage and the lower passage communicate with each other by the rotation of the stirring shaft in the penetrating direction and are blocked by the rotation of the withdrawing direction. That is, the passage / interruption action of the passage is automatically performed by the rotation of the stirring shaft. Therefore, there is no error in the passage opening / closing operation, and the improved material clogging prevention action is reliably performed.

On the other hand, according to the constitution of claim 3 in which an opening / closing valve which is opened / closed by remote operation is provided as the passage opening / closing means, the structure of the shaft body is simpler than that of the constitution of claim 2. Therefore, processing is easy.

Further, according to the structure of claim 4, the improving material accumulated in the lower passage can be discharged by the compressed air from the auxiliary passage in the drawing step.

Further, according to the structure of the fifth aspect, switching between communication and interruption of the upper passage and the auxiliary passage with respect to the lower passage is simultaneously performed in conjunction with the switching between penetration and withdrawal. That is, it is possible to perform communication / blocking of the upper passage and the lower passage and improvement row / blocking of the auxiliary passage and the lower passage by one passage opening / closing means. Therefore, the structure is simple and the cost is low as compared with the case where the opening / closing means is provided separately.

[0018]

EXAMPLE 1 First Example (see FIGS. 1 to 5) FIG. 5 shows an overall schematic structure of a ground improvement machine. In the figure, 1 is a base, 2 is a leader standing on the front surface of the base 1, 3 is a driving device 3 suspended on the front side of the reader 2, and a stirring shaft 4 is provided by the driving device 3. Then, the stirring device 5 attached to the lower end of the stirring shaft 4 is rotationally driven in the normal direction (when penetrating) and in the reverse direction (when extracting).

The structure of the stirring device 5 is shown in FIGS.

As shown in FIG. 1, the stirring device 5 comprises a shaft body 6 on which outer stirring blades 7, 8 and 9 of upper, middle and lower stages are mounted.

The shaft body 6 is the upper shaft 1 connected to the stirring shaft 4.
0 and a lower shaft 11 are axially divided into two, and an upper shaft 10
Upper stirring blade 7, lower shaft 11 both middle and lower stirring blades 8,
9 are attached.

12 is a packing provided between the end faces of the shafts 10 and 11 facing each other, and 13 is a thrust plate for connecting the shafts 10 and 11 in the axial direction.

The upper shaft 10 and the lower shaft 11 are connected by a pawl clutch mechanism C.

The claw clutch mechanism C will be described with reference to FIG.
As shown in FIG. 4, the claws 14 are provided on the outer peripheral surface of the lower end portion of the upper shaft 10.
Are projected over a predetermined angle range.

On the other hand, at the upper end of the lower shaft 11, the upper shaft 10
Is provided with a cylindrical portion 15 into which the lower end portion of the claw 14 is fitted, and the claw 14 has a circumferential wall wider than the claw 14 (for example, a difference of 90 °, which will be described in this example below). 14
A notch 16 is provided in which is fitted.

As a result, the angle difference θ between the claw 14 and the notch 16
The upper shaft 10 and the lower shaft 11 are relatively rotatably connected to each other within a range of 90 ° (see FIG. 3). That is, the rotational force of the stirring shaft 4 is transmitted to the upper shaft 10, and the upper shaft 1
A rotational force of 0 is transmitted to the lower shaft 11 with a 90 ° play.

On the other hand, on the upper shaft 10 and the lower shaft 11,
Improvement material passages (hereinafter, referred to as upper passages and lower passages) 17 and 18 are provided in respective axial center portions in a tunnel shape over the entire length and in a state of communicating with each other at a joint between both shafts 10 and 11. The improving material and compressed air supplied from a feeder and a compressor (not shown) to the hollow portion of the stirring shaft 4 are sent into both the passages 17 and 18.

The ends of the passages 17 and 18 on the joint side are formed to be inclined with respect to the axis L of the shaft body 6, and the openings 17a and 18a on the joint side are formed in the radial direction with respect to the axis L of the shaft body. It is displaced by the same amount.

Thus, the 90 of the upper shaft 10 and the lower shaft 11
Due to the relative rotation of °, both passages 17 and 1 as shown in FIG.
Switching between a state in which 8 is in communication (hereinafter referred to as a communication state) and a state in which both passages 17 and 18 are displaced by 90 ° in the circumferential direction as shown in FIG. Is configured.

Further, as shown in FIG. 1, an upper discharge port 19 is provided at the root of the upper stirring blade 7 in communication with the upper passage 17, and a lower discharge port 20 is provided at the lower part of the lower stirring blade 9. It is provided so as to communicate with the passage 18, and the improving material and the compressed air are discharged from these discharge ports 19 and 20.

The discharge ports 19 and 20 are provided with a known valve mechanism (not shown) (see, for example, Japanese Patent Publication No. 60492).
The upper discharge port 19 is opened only when the stirring shaft 4 is pulled out, and the lower discharge port 20 is opened only when the stirring shaft 4 is inserted.

Next, the operation of this stirring device will be described.

A. At the time of penetration of the stirring shaft 4 At the time of penetration, the stirring shaft 4 and the upper shaft 10 rotate (normally rotate) in the direction of arrow a in FIG.

At this time, the pawl 14 of the pawl clutch mechanism C is located at the end of the notch 16 in the direction of rotation as shown by the phantom line in the figure, and the rotational force of the upper shaft 10 remains unchanged.
It is transmitted to 1. As a result, the upper, middle and lower stirring blades 7, 8 and 9 simultaneously rotate in the same direction.

At this time, the upper passage 17 and the lower passage 1
8 is in a communication state, and the improving material and compressed air are in both passages 1
7 and 18 can be supplied.

In this case, during the penetration, only compressed air is supplied to prevent backflow of soil from the lower discharge port 20,
It is discharged from the discharge port 20 into the ground.

Then, when the predetermined depth is reached, the supply of the improving material is started, and the improving material is discharged into the ground through the lower discharge port 20, and is mainly stirred by the lower stirring blade 9 and mixed with the soil.

In FIGS. 3 and 4, the upper passage 17 shown by a chain double-dashed line is shown with a larger diameter than the lower passage 18 in order to clarify the distinction between the two passages 17, 18, but they have the same diameter. Good.

B. At the time of pulling out the stirring shaft 4 The stirring shaft 4 and the upper shaft 10 are rotationally driven in the direction opposite to that at the time of penetration (the arrow B direction in FIG. 4).

At this time, the claw 14 of the claw clutch mechanism C rotates 90 ° in the notch 16 and moves to the position of the imaginary line in FIG.
After that, the rotational force transmission action from the upper shaft 10 to the lower shaft 11 is started.

Due to the relative rotation of the two shafts 10 and 11, the two passages 17 and 18 are turned to the closed state as shown in FIG. 4, so that the supply of the improving material and the compressed air to the lower passage 18 is stopped and the improving material is stopped. The ejection action is performed only from the upper discharge port 19.

Therefore, at the time of this withdrawal, there is no possibility that the improving material is deposited in the lower passage 18 and is compressed by the compressed air to be solidified.

Second Embodiment (Refer to FIGS. 6 to 8) Only differences from the first embodiment will be described.

The auxiliary passage 21 to which compressed air is supplied to the upper shaft 10 is displaced by 90 ° in the circumferential direction with respect to the upper passage 17 and has the same radius as the passage 17 with respect to the axis L. It is provided offset in the direction.

In this way, at the time of penetration, that is, both passages 1
When 7 and 18 are in communication with each other, the auxiliary passage 21 is blocked as shown in FIGS.
The auxiliary passage 21 communicates with the lower passage 18 as shown in FIG.

Therefore, if compressed air is supplied to the auxiliary passage 21 at this time, this compressed air will flow into the lower passage 18, so that even if the improving material remains in the passage 18,
This retention improver can be discharged to the outside by compressed air.

In the case of adopting this structure, it is necessary to configure the valve mechanism of the lower discharge port 20 so that the lower discharge port 20 opens at the time of withdrawal.

Third Embodiment (see FIG. 9) In the first and second embodiments, the upper passage 17 and the lower passage 1
In contrast to the slide valve structure using the pawl clutch mechanism C as a passage opening / closing means for connecting / disconnecting the 8th,
In the embodiment, the shaft body 6 is integrally formed over the entire length, and a remotely operated pinch valve 22 is provided between the upper and lower passages 17 and 18 of the shaft body 6.
It is configured to connect and disconnect 7,8.

In the figure, 23 is an operation air passage for sending operation air to the pinch valve 22.

Alternatively, an electromagnetic valve may be used instead of the pinch valve 22.

By the way, in the first and second embodiments, the joint side ends of both the upper and lower passages 17 and 18 are formed to be inclined so that the joint side openings 17a and 18a are formed in the radial direction with respect to the shaft body axis L. It was offset to the both passages 17,
The entire 18 may be provided straight at an offset position.

[0052]

As described above, according to the present invention, the improving material passage into which the improving material is sent together with the compressed air is divided into the upper passage and the lower passage on the shaft body having the upper and lower stirring blades mounted thereon. Since the passage opening / closing means blocks both passages when the stirring shaft is pulled out to block the improvement material and the compressed air from flowing into the lower passage, the improvement material is accumulated in the lower passage. Caking can be prevented.

Therefore, the cleaning work for removing the deposit improving material by the manual work of a person is not required, so that the loss of the construction time for the cleaning work is eliminated and the construction efficiency is improved.

In this case, according to the second aspect of the invention, the improvement material passage divided into the upper shaft and the lower shaft communicates with each other by the rotation of the stirring shaft in the penetration direction, and is blocked by the rotation of the withdrawal direction. With this configuration, the opening / closing action of the improvement material passage is automatically performed by the rotation of the stirring shaft. Therefore, there is no error in the passage opening / closing operation, and the improved material clogging prevention action is reliably performed.

On the other hand, according to the invention of claim 3 in which an opening / closing valve which is opened / closed by remote control is provided as the passage opening / closing means in the improved material passage, machining of the shaft body is easier than in the configuration of claim 2. The structure is simple.

According to the fourth aspect of the present invention, the improving material accumulated in the passage on the lower stirring blade side before the drawing process can be discharged by the compressed air from the auxiliary passage.

Further, according to the invention of claim 5, the switching of communication / blocking of the upper passage and the auxiliary passage with respect to the lower passage is simultaneously performed in conjunction with the switching of penetration / withdrawal. That is, it is possible to perform communication / blocking of the upper passage and the lower passage and improvement row / blocking of the auxiliary passage and the lower passage by one passage opening / closing means. Therefore, the structure is simple and the cost is low as compared with the case where the opening / closing means is provided separately.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a partially exploded perspective view of a shaft body according to the embodiment.

FIG. 3 is an enlarged sectional view taken along line III-III in FIG.

4 is a view corresponding to FIG. 3 in a state in which the upper shaft of the shaft body is rotated from the state of FIG.

FIG. 5 is an overall schematic configuration diagram of a ground improvement machine equipped with the stirring device of the embodiment.

FIG. 6 is a partial vertical sectional view of a shaft body according to a second embodiment of the present invention.

7 is a sectional view taken along line VII-VII of FIG.

8 is a view corresponding to FIG. 7 in a state where the shaft is rotated from the state of FIG. 7.

FIG. 9 is a schematic configuration diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 5 Stirrer 6 Shaft 7 Upper stirrer 8 Middle stirrer 9 Lower stirrer 10 Upper shaft 11 constituting the shaft 11 Lower shaft 17 Upper passage 18 constituting the improvement material passage 18 Lower passage C constituting passage opening / closing means Claw clutch mechanism 19 Upper discharge port 20 Lower discharge port 21 Auxiliary passage 22 Pinch valve as passage opening / closing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Kurosawa 4-10-10-903 Hirai, Edogawa-ku, Tokyo

Claims (5)

[Claims] 1. A plurality of upper and lower stirring blades are mounted at intervals on the outer circumference of a shaft body connected to the lower end of the stirring shaft,
In the agitator for soil improvement, wherein the shaft body is provided with an improvement material passage through which the improvement material is sent together with compressed air, and each of the upper and lower stirring blades is provided with an improvement material discharge port communicating with the improvement material passage. The material passage is divided into an upper passage and a lower passage with an intermediate point between the upper stirring blade and the lower stirring blade as a boundary, and the upper passage and the lower passage are communicated with each other when the stirring shaft penetrates and withdrawn. An agitator for ground improvement, characterized by comprising passage opening / closing means for shutting off. 2. The ground improvement agitator according to claim 1, wherein the shaft body is axially divided into an upper shaft and a lower shaft with a joint between the upper passage and the lower passage as a passage opening / closing means. The lower shaft is connected to the upper shaft so as to be rotatable relative to the upper shaft within a certain angle range, and the upper passage and the lower passage are connected and disconnected by the relative rotation of the upper shaft and the lower shaft. A stirrer for ground improvement, characterized in that the opening is provided in a state of being displaced in the radial direction with respect to the axis of the shaft. 3. The ground improvement stirring shaft according to claim 1, wherein an opening / closing valve which is opened / closed by remote control is provided between the upper passage and the lower passage as the passage opening / closing means. apparatus. 4. The ground improvement agitator according to claim 1, wherein an auxiliary passage through which compressed air passes is provided in the shaft body along the upper passage, and the auxiliary passage is provided in the lower passage. On the other hand, an agitator for ground improvement, which is provided with an auxiliary passage opening / closing means for blocking the agitating shaft when it penetrates and communicating with the agitating shaft for withdrawal. 5. The ground improvement agitator according to claim 2, wherein an auxiliary passage through which compressed air is passed is provided in the upper shaft along the upper passage, and by the relative rotation of the upper shaft and the lower shaft. It is characterized in that the opening on the seam side is displaced in the radial direction with respect to the axial center of the shaft body and is also displaced in the circumferential direction with respect to the upper passage so as to communicate with the lower passage when pulled out. Agitating device for soil improvement.