JP2021156005A - Rotary nozzle - Google Patents

Abstract

To provide a rotary nozzle which enables control of rotation of a rotary part in the underground of a foundation.SOLUTION: A rotary nozzle 1 is used for a foundation improvement device and rotated by a reactive force of a jet force of a fluid S. This nozzle is constructed such that a rotary part 20 having a fluid passage 21 formed to communicate with a fluid passage 12 is provided so as to be rotatable about a shaft 11 of a fixed part 10 having the fluid passage 12 formed so as to allow passage of the fluid S, a part 21b of the fluid passage 21 of the rotary part 20 is obliquely inclined outside a vertical surface with respect to the fluid passage 12, and formed toward the outer peripheral surface, a tip port 21c is provided to the tip of the inclined part 21b, the rotary part 20 is made rotatable about the shaft 11 by the reactive force of the jet force of the fluid S jetted from a jet nozzle 25 attached to the tip port 21c, and an elastic body 27 for sealing a space 26 between the fixed part 10 and the rotary part 20 and applying a brake on the rotary part 20 through expansion by a fluid A supplied from the other fluid passage 13 of the fixed part 10 is provided to an opening 26a of the space 26.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotary nozzle used in a ground improvement device for drilling and improving the ground.

As a rotary nozzle of this type, for example, there is one disclosed in Patent Document 1. The rotary nozzle described in Patent Document 1 is used in a ground improvement device that injects a fluid into the ground at high pressure from an injection nozzle to drill and improve the ground, and rotates by the reaction force of the injection force of the fluid. It is a thing. That is, the rotating nozzle rotatably provides a rotating portion in which a fluid passage communicating with the fluid passage is formed around the shaft portion of the fixed portion in which the fluid passage through which the fluid flows is formed, and the fluid in the rotating portion. A part of the passage is formed by inclining a predetermined angle with respect to the fluid passage of the fixed portion toward the outer peripheral side, and an injection nozzle is attached to the tip port of the inclined fluid passage to supply the fluid injected from the injection nozzle. The rotating part is made rotatable around the shaft part by the reaction force of the injection force.

Japanese Unexamined Patent Publication No. 2018-123598

However, in the conventional rotary nozzle, there is no method for controlling the rotation speed of the rotating portion to a state suitable for the purpose of drilling holes in the ground or improving the ground. Further, when drilling or improving the ground, there is a problem that foreign matter such as earth and sand or dust is mixed in the gap formed between the fixed portion and the rotating portion in the soil and the rotation of the rotating portion is stopped. ..

Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotating nozzle capable of controlling the rotation of a rotating portion in the soil of the ground.

The invention of claim 1 is used in a ground improvement device that injects a fluid into the ground at high pressure from an injection nozzle to drill holes and improve the ground, and is a rotating nozzle that rotates by the reaction force of the injection force of the fluid. A rotating portion in which a fluid passage communicating with the fluid passage is formed is rotatably provided around a shaft portion of the fixed portion in which the fluid passage through which the fluid flows is formed, and outside the vertical surface of the fixed portion with respect to the fluid passage. A part of the fluid passage of the rotating portion is slanted to be formed toward the outer peripheral side, a tip port is provided at the tip of a part of the slanted fluid path, an injection nozzle is attached to the tip port, and the injection is performed. The reaction force of the injection force of the fluid injected from the nozzle makes the rotating portion rotatable around the shaft portion, and seals the space formed between the fixed portion and the rotating portion. It is characterized in that an elastic body that expands and deforms by a fluid supplied from another fluid passage formed in the fixed portion and applies a brake to the rotating portion is provided in the opening of the space.

The invention of claim 2 is the rotary nozzle according to claim 1, wherein a fluid passage different from the fluid passage of the shaft portion is formed in the fixed portion, and the fluid supplied from the other fluid passage is described. The feature is that the fluid can be freely discharged from the gap between the fixed portion and the rotating portion.

The invention of claim 3 is the rotary nozzle according to claim 1 or 2, wherein a rotation detection sensor for detecting the rotation state of the rotating portion is provided on the opposite surface side of the fixed portion and the rotating portion. It is characterized by.

As described above, according to the invention of claim 1, the elastic body for applying the brake to the rotating portion is provided in the opening of the space formed between the fixed portion and the rotating portion, so that the ground is in the soil. It is possible to control the rotation of the rotating part in.

According to the invention of claim 2, a fluid passage different from the fluid passage of the shaft portion is formed in the fixed portion, and the fluid supplied from the other fluid passage is discharged from the gap between the fixed portion and the rotating portion. By making the fluid flowable, it is possible to prevent foreign matter such as earth and sand and dust from entering the gap between the fixed portion and the rotating portion, and it is possible to ensure stable rotation of the rotating portion.

According to the invention of claim 3, the rotation of the rotating portion in the soil of the ground is provided by providing the rotation detection sensor for detecting the rotation state of the rotating portion on the opposite surfaces of the fixed portion and the rotating portion. You can figure out the number.

It is sectional drawing of the rotary nozzle of one Embodiment of this invention. It is a front view of the said rotary nozzle. It is sectional drawing which follows the line III-III in FIG. It is sectional drawing which follows the IV-IV line in FIG. It is explanatory drawing which shows the rotation principle of the said rotary nozzle. It is sectional drawing which shows the state which brake was applied to the rotating part of the said rotary nozzle. It is sectional drawing which shows the state which the air was exhausted from the gap between the fixed part and the rotating part of the rotary nozzle.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 is a cross-sectional view of a rotary nozzle according to an embodiment of the present invention, FIG. 2 is a front view of the rotary nozzle, FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 5 is an explanatory view showing the rotation principle of the rotating nozzle, FIG. 6 is a cross-sectional view showing a state in which the rotating portion of the rotating nozzle is braked, and FIG. 7 is a cross-sectional view of the fixed portion and the rotating portion of the rotating nozzle. It is sectional drawing which shows the state which air was exhausted from the gap between them.

As shown in FIG. 1, the rotary nozzle 1 is a ground improvement device (not shown) for drilling and improving the ground by injecting a fluid S such as water or cement slurry from the injection nozzle 25 into the ground (not shown) at high pressure. It is used for (omitted), and is used in the fixed portion 10 and the main fluid passage 12, which are holders formed up to the shaft portion 11 in which the main fluid passage (fluid passage) 12 through which the fluid S flows flows to the center. A sub-fluid passage (fluid passage) 21 that communicates with each other is formed, and includes a rotating portion 20 that is a rotating body that rotates around a shaft portion 11 of the fixed portion 10 by a reaction force of an injection force of the fluid S.

The fixed portion 10 is formed in a columnar shape having a large diameter, and a shaft portion 11 having a small diameter and a columnar stepped shape is integrally projected at the center of the front surface 10a thereof. A rotating portion 20 is rotatably supported by the shaft portion 11 via ball bearings 23 located in the front and rear positions.

The main fluid passage 12 of the fixing portion 10 has a large-diameter inner peripheral surface portion 12a, a conical inner surface portion 12b, and a shaft portion 11 from the large-diameter side to the small-diameter side from the center of the protruding portion 10c protruding from the rear surface 10b of the fixing portion 10. It has a small-diameter inner peripheral surface portion 12c formed and a communication passage 12d bent at a right angle from the tip of the small-diameter inner peripheral surface portion 12c. Then, the fluid S is supplied from the large-diameter inner peripheral surface portion 12a of the main fluid passage 12 into the sub-fluid passage 21 of the rotating portion 20.

As shown in FIG. 1, the rotating portion 20 is formed in a columnar shape having the same diameter as the outer diameter of the fixing portion 10, and a central hole 22 having a circular cross section through which the shaft portion 11 of the fixing portion 10 is inserted is inserted in the center thereof. Is formed.

Further, as shown in FIGS. 1 and 2, the sub-fluid passage 21 of the rotating portion 20 faces the annular passage 21a communicating with the main fluid passage 12 of the fixed portion 10 and the annular passage 21a toward the front surface 20a. It has a pair of branch passages (partial) 21b and 21b formed radially and 180 ° apart. As shown in FIG. 1, the gap between the central hole 22 of the rotating portion 20 and the annular passage 21a of the sub-fluid passage 21 is fitted into each annular recess 22a formed in the central hole 22. The seal ring 24 is blocked so that the fluid S does not leak.

That is, as shown in FIGS. 1 and 2, the rotating portion 20 has a pair of branch passages 21b and 21b communicating with the annular passage 21a of the subfluid passage 21 with respect to the main fluid passage 12 in which the fixed portion 10 is horizontal. It is formed radially from the outer peripheral side of the rotating portion 20 toward the front surface 20a by tilting it by a predetermined angle θ three-dimensionally outside the vertical plane. A tip port 21c is provided at the tip of each of the inclined branch passages 21b. Injection nozzles 25 are attached to the pair of tip ports 21c and 21c by screwing, respectively, and the shaft portion 11 of the fixing portion 10 is centered by the reaction force of the injection force of the fluid S injected from each injection nozzle 25. The rotating portion 20 is designed to rotate.

More specifically, as shown in FIGS. 1 and 2, the pair of branch passages 21b and 21b of the rotating portion 20 are inclined by a predetermined angle θ with respect to the shaft portion 11 of the fixed portion 10, so that each branch passage 21b is inclined. When the fluid S is injected at high pressure from the injection nozzle 25 attached to the tip port 21c of the above, the rotating portion 20 rotates about the shaft portion 11 of the fixed portion 10 by the above-mentioned injection force. That is, as shown in FIG. 5, where F is the injection force of the fluid S injected at high pressure from the injection nozzle 25, F is a horizontal component of the injection force F in a plane orthogonal to the shaft portion 11 of the fixed portion 10. × sinθ = F'acts. This horizontal component force F'is a propulsive force (reaction force), and the rotating portion 20 rotates about the shaft portion 11 of the fixed portion 10.

Further, as shown in FIGS. 1 and 6, a recess 20c having a circular cross section is formed on the rear surface 20b of the rotating portion 20. A space 26 is formed between the recess 20c and the shaft portion 11 of the fixing portion 10. In the space 26 formed between the shaft portion 11 of the fixed portion 10 and the recess 20c of the rotating portion 20, air (other fluid passages) 13 formed in the fixed portion 10 dedicated to the brake is used as air ( Fluid) A is supplied. Further, in the opening 26a of the space 26, a hard rubber (elastic body) 27 that expands and deforms by the air A supplied from the airline 13 dedicated to the brake via the air hose 14 and applies the brake to the rotating portion 20 is provided in the opening 26a. It is provided so as to block the. The hard rubber 27 is formed in an annular shape having a U-shaped cross section, and is provided so as to be able to be prevented from coming off via an annular support member 28. As a result, the inner peripheral portion 27a of the hard rubber 27 is pressed against the outer peripheral surface 11b of the stepped large-diameter portion of the shaft portion 11 of the fixed portion 10, and the outer peripheral portion 27b of the hard rubber 27 is a recess of the rotating portion 20. It is pressure-welded to the inner peripheral surface 20d of 20c.

Further, as shown in FIGS. 1 and 7, a second space 29 is formed between the front surface 10a of the fixing portion 10 and the hard rubber 27. In the second space 29, air (fluid) A is supplied to the fixed portion 10 from an exhaust-dedicated airline (another fluid passage) 15 formed separately from the main fluid passage 12 of the shaft portion 11. It has become like. The air A supplied from the exhaust-dedicated airline 15 into the second space 29 via the air hose 16 has a gap t formed between the front surface 10a of the fixed portion 10 and the rear surface 20b of the rotating portion 20. It is designed to be exhausted to the outside. The air A exhausted to the outside blows away foreign matter B such as earth and sand and dust that are about to be mixed into the gap t.

Further, as shown in FIG. 1, the rotating portion 20 rotates on the bottom surface 20e side of the front surface 11c of the stepped large-diameter portion of the shaft portion 11 of the fixing portion 10 and the recess 20c of the rotating portion 20 facing the front surface 11c. A proximity sensor (rotation detection sensor) 30 for detecting the situation is provided.

As shown in FIGS. 1 and 3, the proximity sensor 30 is attached to the bottom surface 20e of the concave portion 20c of the rotating portion 20, and has an annular plate-shaped ring 31 having concave portions 31a and convex portions 31b alternately, and this circle. A sensor unit 32 that calculates and detects the number of rotations of the rotating unit 20 from the number of concave portions 31a and convex portions 31b of the ring plate-shaped ring 31, and a cable 33 that outputs a detection signal from the sensor unit 32 to the ground. It has. The accuracy of the proximity sensor 30 can be improved by increasing the distance between the concave portion 31a and the convex portion 31b formed on the ring plate 31 (increasing the number of unevenness).

According to the rotary nozzle 1 of the above embodiment, as shown in FIG. 6, when drilling or improving the ground, the hard rubber 27 that brakes the rotary portion 20 has a large step on the shaft portion 11 of the fixing portion 10. The hard rubber 27 is provided in the opening 26a of the space 26 formed between the outer peripheral surface 11b of the diameter portion and the inner peripheral surface 20d of the concave portion 20c of the rotating portion 20, and the hard rubber 27 is provided by the air A supplied from the air line 13 dedicated to the brake. The rotation of the rotating portion 20 in the soil of the ground can be controlled by expanding and deforming the rotating portion 20 so as to apply the brake and operating the brake pressure from the ground.

Further, when drilling or improving the ground, as shown in FIG. 7, an air line 15 dedicated to exhaust gas is formed in the fixed portion 10 as a fluid passage different from the main fluid passage 12 of the shaft portion 11. The air A supplied from the exhaust-dedicated air line 15 is always exhausted from the gap t between the front surface 10a of the fixed portion 10 and the rear surface 20b of the rotating portion 20, so that the air A is always exhausted from the front surface 10a of the fixed portion 10. It is possible to prevent foreign matter B such as earth and sand from being mixed into the gap t between the rotating portion 20 and the rear surface 20b, and it is possible to ensure stable rotation of the rotating portion 20.

Further, when drilling or improving the ground, as shown in FIG. 1, the rotating portion is located between the outer peripheral surface 11b of the stepped large-diameter portion of the shaft portion 11 of the fixing portion 10 and the bottom surface 20e of the recess 20c of the rotating portion 20. By providing the proximity sensor 30 that detects the rotation speed of 20, the rotation speed of the rotating portion 20 in the soil of the ground can be grasped.

According to the rotary nozzle of the above embodiment, the pair of injection nozzles are provided on the front side of the rotating portion in an inclined manner, but a plurality of injection nozzles may be provided on the outer peripheral surface side of the rotating portion in an inclined manner. In the case of this form, when drilling the ground using the rotary nozzle, high-pressure water is injected from both the inclined injection nozzle on the front side and the inclined injection nozzle on the outer peripheral surface side to drill the hole. When the ground is improved, a steel ball is inserted at the tip of the main fluid passage to close the auxiliary fluid passage to the inclined injection nozzle on the front side, and the cement slurry is injected at high pressure from the inclined injection nozzle on the outer peripheral surface side. And improve the ground.

Further, according to the above embodiment, a pair of inclined injection nozzles are provided on the front surface side of the rotating portion, but three or more may be provided, or a plurality of inclined injection nozzles may be provided on the outer peripheral surface side of the rotating portion.

Further, according to the above-described embodiment, the injection nozzle is provided so as to be inclined on the front side of the rotating portion, and the injection nozzle is not provided on the front surface of the shaft portion of the fixed portion exposed from the central hole of the rotating portion, but is fixed. A main fluid passage may be formed up to the tip of the shaft portion of the portion, and the injection nozzle may be provided on the front surface of the shaft portion of the fixed portion exposed from the central hole of the rotating portion without inclining the injection nozzle.

1 Rotating nozzle 10 Fixed part 11 Shaft part 11c Front surface (opposing surfaces)
12 Main fluid passage (fluid passage)
13 Airline dedicated to brakes (other fluid passages)
15 Airline dedicated to exhaust (another fluid passage)
20 Rotating part 20e Bottom surface (opposing surfaces)
21 Sub-fluid passage (fluid passage)
21a Circular passage 21b Branch passage (partial)
21c Tip port 25 Injection nozzle 26 Space 26a Opening 27 Hard rubber (elastic body)
30 Proximity sensor (rotation detection sensor)
S Water or cement slurry, etc. (fluid)
A air (fluid)
F Injection force F'Reaction force θ Tilt angle t Gap

Claims (3)

In a rotating nozzle that is used in a ground improvement device that injects fluid from an injection nozzle into the ground at high pressure to drill holes and improve the ground, and that rotates by the reaction force of the injection force of the fluid.
A rotating portion in which a fluid passage communicating with the fluid passage is formed is rotatably provided around a shaft portion of a fixed portion in which the fluid passage through which the fluid flows is formed.
A part of the fluid passage of the rotating portion is slanted and formed toward the outer peripheral side outside the vertical surface of the fixed portion with respect to the fluid passage.
A tip port is provided at the tip of a part of the inclined fluid passage, an injection nozzle is attached to the tip port, and the rotating portion is centered on the shaft portion due to the reaction force of the injection force of the fluid injected from the injection nozzle. To be rotatable,
In addition, the space formed between the fixed portion and the rotating portion is sealed, and the rotating portion is braked by being expanded and deformed by the fluid supplied from another fluid passage formed in the fixed portion. A rotary nozzle characterized in that an elastic body for hanging is provided in the opening of the space. The rotary nozzle according to claim 1.
A fluid passage different from the fluid passage of the shaft portion is formed in the fixed portion, and the fluid passage is formed.
A rotating nozzle characterized in that a fluid supplied from the other fluid passage is allowed to flow out from a gap between the fixed portion and the rotating portion. The rotary nozzle according to claim 1 or 2.
A rotary nozzle characterized in that a rotation detection sensor for detecting the rotation state of the rotating portion is provided on the opposite surface side of the fixed portion and the rotating portion.

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