JP2022001711A - High-pressure jetting nozzle device and ground improvement device equipped therewith - Google Patents

Abstract

To provide a high-pressure jetting nozzle device and a ground improvement device equipped with the same, which can discharge cut soil of the ground to a ground surface as waste mud, and also sufficiently increase a jet arrival distance of a hardener liquid jetted from the high-pressure jetting nozzle device.SOLUTION: Since an air cover 25 is provided with inclined grooves inclined obliquely almost in the same direction toward a tip formed on an inner surface, the compressed air jetted from the air cover 25 can be swirled around cement milk jetted from a nozzle body 24, which increases the cutting capacity of the cement milk jetted from the nozzle body 24, thereby destroying a tissue structure of the ground and allowing the cement milk to be jetted over a long distance.SELECTED DRAWING: Figure 14

Description

The present invention is a high-pressure injection nozzle device provided on the side surface of a monitor that communicates with the inside of the curing material liquid supply pipe in the injection rod and is connected to the tip of the injection rod, and a ground improvement device provided with the high-pressure injection nozzle device.

Conventionally, there has been known a high-pressure injection nozzle device provided on the side surface of a monitor which communicates with the inside of a curing material liquid supply pipe in an injection rod and is connected to the tip of the injection rod, and a ground improvement device provided with the high-pressure injection nozzle device.

In this type of high-pressure injection nozzle device, a material liquid injection nozzle is provided inside the high-pressure injection nozzle device, an air injection nozzle is formed on the outside, and a cured material liquid is injected from the high-pressure injection nozzle device and air is injected. When compressed air is jetted from the nozzle at high pressure, the curing material liquid is jetted from the inside of the high-pressure injection nozzle device, and the compressed air is jetted from the outside (outer peripheral portion) to compress around the jet of the curing material liquid. An air vapor layer film was formed, and the jet reach range could be increased as compared with the case where there was no compressed air air layer film (for example, Patent Document 1). Then, the cut soil from which the ground was cut becomes waste mud, which is transported to the upper part by the compressed air ejected from the air injection nozzle and can be discharged to the ground surface.

Japanese Unexamined Patent Publication No. 2018-150706

However, in the conventional ground improvement device, when the compressed air sent from the compressor is injected at high pressure from the air injection nozzle, if the diameter of the air injection nozzle is a certain size, the flow rate is compressed to be equal to or higher than the maximum output of the compressor. Since air cannot be injected from the air injection nozzle 122, it is necessary to increase the size of the diameter of the air injection nozzle in order to discharge the cut soil from the ground to the ground surface as waste mud. If the nozzle diameter is increased, a vapor phase film of compressed air cannot be sufficiently formed around the jet of the cured material liquid, and the injection reach of the cured material liquid injected from the high-pressure injection nozzle device cannot be increased so much. There was a problem.

The present invention has been made in view of the above problems, and even a compressor having a predetermined maximum output can discharge the cut soil of the ground to the ground surface as waste mud and is injected from a high-pressure injection nozzle device. It is an object of the present invention to provide a high-pressure injection nozzle device capable of sufficiently increasing the injection reach of a hardened material liquid and a ground improvement device equipped with the high-pressure injection nozzle device.

In order to solve the above problems and achieve the above object, the one according to the first aspect of the present invention communicates with the inside of the curing material liquid supply pipe formed in the axial direction in the injection rod, and the tip of the injection rod. It is a high-pressure injection nozzle device provided on the side surface of the monitor connected to the above, and communicates with the tapered intermediate inner diameter portion formed by reducing the inner peripheral surface toward the tip and the tip of the intermediate inner diameter portion. It communicates with the tip inner diameter portion whose diameter is substantially the same as the diameter of the tip of the intermediate inner diameter portion and the rear end of the intermediate inner diameter portion, and the diameter is substantially the same as or from approximately the same diameter as the diameter of the rear end of the intermediate inner diameter portion. The nozzle body, which has a hollow hardener liquid flow path consisting of the inner diameter of the rear end formed by expanding the diameter toward the rear end, and the inner peripheral surface are inclined in substantially the same direction diagonally toward the tip. It has an air cover in which a plurality of inclined grooves are formed and a compressed air flow path is formed between the nozzle body and the outer peripheral side of the nozzle body, and from the tip between the air cover and the outer peripheral side of the nozzle body. Since the injected compressed air covers the area around the curing material liquid injected from the tip of the nozzle body as a swirling flow, the cutting ability of the curing material liquid injected from the inner diameter of the tip of the nozzle body is increased and hardening is performed. It is characterized by injecting the material liquid to a longer distance.

According to the present invention, since the air cover is provided on the inner peripheral surface with a plurality of inclined grooves inclined in substantially the same direction diagonally toward the tip end, the air injected from the air cover is discharged from the nozzle body. It will swirl around the curing material liquid sprayed from the tip of. As a result, the cutting ability of the hardened material liquid sprayed from the tip of the nozzle main body is increased, so that the tissue structure of the ground is destroyed and the hardened material liquid can be sprayed to a longer distance. That is, the compressed air jetted from the tip between the air cover and the outer peripheral side of the nozzle body swirls while covering the area around the curing material liquid jetted from the nozzle body without any gaps, so that the compressed air is swirled from the tip of the nozzle body. The injected hardener liquid is pressed toward the center by the compressed air swirling around it, and the hardener liquid jet immediately after the injection of the hardener liquid jetted from the tip of the nozzle body is unlikely to increase significantly in the radial direction. Therefore, the speed of the curing material liquid can be maintained. In addition, since the ground around the swirling flow is pressed and cut by the swirling flow of compressed air swirling around the hardened material liquid, the compressed air around the hardened material liquid jet flow can be included without gaps, and the air layer is thickened. can do. As described above, since the jet of the hardened material liquid immediately after the injection of the hardened material liquid jetted from the tip of the nozzle body is unlikely to increase significantly in the radial direction, the straightness of the hardened material liquid jet can be increased. Since the compressed air layer around the hardener liquid jet immediately after injection from the nozzle body can be thickened, the ground around the hardener liquid jet immediately after injection from the nozzle body is the hardener liquid jet. It is also possible to reduce the obstacles to the flow of the water. As a result, it is possible to lengthen the region (potential core region) in which the speed of the cured material liquid jetted from the nozzle main body does not decrease, and the cured material liquid can be sprayed to a longer distance. Furthermore, cavitation-induced cavities (air bubbles) are generated in the peripheral area where the pressure of the hardened material liquid is low, and these cavities collapse due to the resistance of the ground to the hardened material liquid (pressure rise). Since a large impact force is generated when the cavity collapses, the large impact force generated when the cavity collapses reduces the momentum of the cured material liquid. In the present invention, even if there is a cavity due to cavitation in the peripheral portion of the curing material liquid sprayed from the nozzle body, the compressed air sprayed from between the air cover and the outer peripheral side of the nozzle body is the curing material liquid. Since it swirls while covering the circumference of the hardener without any gaps, it becomes difficult for the hardened material liquid to come into contact with the ground, and it is possible to prevent the cavities existing in the peripheral portion of the hardened material liquid from collapsing. As a result, the region (potential core region) in which the speed of the cured material liquid ejected from the nozzle main body does not decrease can be made longer, and the cured material liquid can be injected to a longer distance. That is, when the compressed air is jetted straight from between the air cover and the outer peripheral side of the nozzle body, the compressed air cannot cover the area around the cured material liquid without any gaps. The non-inclusive part of the air is likely to come into contact with the ground, and the cavity will collapse when the hardened material liquid comes into contact with the surrounding ground. Then, since the momentum of the hardened material liquid is reduced due to the large impact force at the time of collapse of the cavity, the potential core region cannot be made longer and the hardened material liquid cannot be ejected to a longer distance. .. In this way, the compressed air sprayed from between the air cover and the outer peripheral side of the nozzle body swirls while covering the area around the curing material liquid without any gaps, so that the curing material liquid does not easily come into contact with the ground and is cured. Since the collapse of the cavity generated in the peripheral part of the material liquid can be prevented, the region (potential core region) in which the speed of the cured material liquid sprayed from the nozzle body does not decrease can be made longer, and the cured material liquid can be made longer. Can be sprayed to a longer distance.

The second aspect of the present invention is the high pressure injection nozzle device according to the first aspect, and the inclined grooves of the air cover are in the range of 4 to 8 on the inner peripheral surface of the air cover. It is characterized in that it is formed in substantially the same shape.

According to the present invention, the inclined grooves of the air cover are formed on the inner peripheral surface of the air cover in a range of 4 to 8 in substantially the same shape, so that the space between the air cover and the outer peripheral side of the nozzle body portion is formed. The compressed air strongly injected by the large flow flowing along the 4 to 8 inclined grooves from the tip of the nozzle can be swirled together around the curing material liquid injected from the tip of the nozzle body. can. As a result, the cured material liquid ejected from the tip of the nozzle body is pressed more strongly in the central direction by the compressed air swirling around it, and the thickness of the compressed air layer around the cured material liquid jet flow is also made thicker. Can be done. As a result, the region (potential core region) in which the speed of the cured material liquid ejected from the tip of the nozzle main body does not decrease can be lengthened, and the cured material liquid can be injected to a longer distance.

The third aspect of the present invention is the high pressure injection nozzle device according to the second aspect, in which the inclined groove of the air cover is approximately 26.49 toward the tip on the inner peripheral surface of the air cover. It is characterized in that it is inclined diagonally within the range of degrees to approximately 46.68 degrees.

According to the present invention, the inclined groove of the air cover is inclined diagonally in the range of about 26.49 degrees to about 46.68 degrees toward the tip toward the inner peripheral surface of the air cover, so that the nozzle body is inclined. The cured material liquid ejected from the tip of the portion is pressed more strongly in the central direction by the compressed air swirling around the portion, and the thickness of the compressed air layer around the cured material liquid jet can also be made thicker. As a result, the region (potential core region) in which the speed of the cured material liquid ejected from the tip of the nozzle main body does not decrease can be lengthened, and the cured material liquid can be injected to a longer distance.

The fourth aspect of the present invention is the high-pressure injection nozzle device according to the third aspect, and the nozzle body and the air cover are attached to the opening on the rear end side of the inclined groove of the air cover. In this state, the diameter is approximately 42.1% to 64.1% with respect to the circle whose diameter is the length from the substantially center of the nozzle body to the maximum outer portion on the rear end side of the inclined groove of the air cover. It is characterized by being.

According to the present invention, with respect to a circle whose diameter is the length of the opening on the rear end side of the inclined groove of the air cover from the substantially center of the nozzle body to the maximum outer portion on the rear end side of the inclined groove of the air cover. Since it is approximately 42.1% to approximately 64.1%, the opening on the rear end side of the inclined groove of the air cover can be widened, and a larger volume of compressed air can be strongly injected.

The fifth aspect of the present invention is the high-pressure injection nozzle device according to the first aspect, and a flow path for dividing a hollow cross section into a plurality of spaces in the inner diameter portion of the rear end of the nozzle body portion. A split portion is formed, and the flow path split portion is located at substantially the center of the hollow rear end inner diameter portion near the flow path split portion, and is 2% to 2% of the hollow shape cross-sectional area of the rear end inner diameter portion near the flow path split portion. After having a portion having an area of 20% and the curing material liquid flowing through the inner diameter portion of the rear end of the nozzle body portion being more finely stratified in each space divided by the flow path dividing portion, the intermediate inner diameter portion Since the diameter is reduced and sent toward the tip in a hollow space where no tangible object exists, the cutting ability of the hardened material liquid sprayed from the inner diameter of the tip of the nozzle body is increased, and the hardened material liquid can be sent to a longer distance. It is characterized by being able to inject.

According to the present invention, the curing material liquid flowing in the substantially central portion of the inner diameter portion of the rear end of the nozzle body collides with the substantially central portion of the flow path dividing portion, and the cured material in the substantially central portion of the inner diameter portion of the rear end colliding with the collision material. Since the liquid flows into each flow path divided by the flow path dividing portion and is sent toward the inner peripheral surface of the intermediate inner diameter portion formed by reducing the diameter while increasing the speed, the inner circumference of the intermediate inner diameter portion is reached. The thickness of the boundary layer of the turbulent flow generated on the surface can be reduced, and the laminar flow can be made finer. As a result, by increasing the cutting ability of the hardened material liquid sprayed from the material liquid injection nozzle at the tip of the nozzle main body, the tissue structure of the ground can be destroyed and the hardened material liquid can be sprayed to a longer distance. That is, since the thickness of the boundary layer of the turbulent flow generated on the inner peripheral surface of the intermediate inner diameter portion can be reduced, the cured material liquid injected from the injection port of the material liquid injection nozzle at the tip of the nozzle body is almost the same as the injection port. It will be injected at substantially the same speed on the entire surface. As a result, it is possible to lengthen the region (potential core region) where the speed of the cured material liquid sprayed from the injection port of the material liquid injection nozzle at the tip of the nozzle body does not decrease, and the cured material liquid is sprayed to a longer distance. be able to.

The sixth aspect of the present invention is a ground improvement device provided with a high-pressure injection nozzle device according to any one of the first to fifth aspects mounted on a monitor.

According to the high-pressure injection nozzle device of the present invention, even with a compressor having a predetermined maximum output, the cutting soil of the ground can be discharged to the ground surface as waste mud, and the hardening material injected from the high-pressure injection nozzle device can be discharged. The spray reach of the liquid can be sufficiently increased.

It is a figure which shows the construction state of the ground improvement apparatus to which the high pressure injection nozzle apparatus is attached in one Embodiment of this invention. (A) FIG. 3 is an external perspective view of a monitor equipped with the high-pressure injection nozzle device. (B) It is a figure which shows the coupling pin which connects an injection rod and a monitor. FIG. 2 is a cross-sectional view taken along the line AA of FIG. (A) It is an enlarged view of the PP part of FIG. (B) It is a figure which shows the nozzle main body part mounting hole of a monitor. It is a figure which shows the component of the high pressure injection nozzle apparatus in one Embodiment of this invention. It is sectional drawing of the same component. (A) It is a front perspective view of the air cover of the high pressure injection nozzle device in one Embodiment of this invention. (B) It is a rear perspective view of the air cover of the high pressure injection nozzle device. (C) It is a rear view of the air cover of the high pressure injection nozzle device. (D) is a cross-sectional view taken along the line DD of FIG. It is a side view of the air cover of the high pressure injection nozzle device. 8A cross-sectional view to MM cross-sectional view of FIG. It is a figure which shows the calculation method of the inclination angle of the air cover of the high pressure injection nozzle apparatus in one Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line BB of FIG. FIG. 3 is a sectional view taken along the line CC of FIG. It is a figure which shows the assembly method of the high pressure injection nozzle device and the peripheral device thereof in one Embodiment of this invention. It is a figure which shows the mounting method of the high pressure injection nozzle device. It is a figure which shows the injection state from the tip nozzle of the high pressure injection nozzle device. 8A cross-sectional view to MM cross-sectional view of FIG. 8 in the first modification of the present invention. It is a figure which shows the calculation method of the inclination angle of the inclination groove of the air cover of the high pressure injection nozzle device in the same modification 1. FIG. It is a figure which shows various inclination angles of the inclination groove of the air cover in the said modification 1. FIG. It is a figure which shows the opening ratio of the side surface on the rear end side of the air cover of the high pressure injection nozzle device in the modification 2 of this invention.

Hereinafter, an embodiment of the high-pressure injection nozzle device 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a construction status of a ground improvement device to which a high-pressure injection nozzle device according to an embodiment of the present invention is mounted.

As shown in FIG. 1, the monitor 3 is coupled and attached to the tip of the injection rod 2. Water (liquid) supplied through the injection rod 2 and the inside of the monitor 3 is ejected from the tip nozzle 4 provided at the tip of the monitor 3, and also from the high-pressure injection nozzle device 1 provided on the side surface of the monitor 3. Is sprayed with cement milk (hardening material liquid) and air supplied through the injection rod 2 and the monitor 3.

The working machine 5 is a machine that supports the injection rod 2 and moves, rotates, and swings the injection rod 2 up and down. As a result, the injection rod 2 and the monitor 3 can be rotated and swung as well as vertically moved by the working machine 5.

A swivel 6 is attached to the rear end of the injection rod 2. Further, the injection rod 2 is composed of a double pipe, and cement milk or water (liquid) is supplied to the cement milk combined water supply path 7 inside the injection rod 2, and the outer air supply path inside the injection rod 2 is supplied. Air is supplied to No. 8 (see FIG. 3). In the present embodiment, the cement milk (hardened material liquid) supply pipe and the water supply pipe are configured as one supply pipe by using the cement milk combined water supply passage 7, but the present invention is not limited to this. The hardener liquid) supply pipe and the water supply pipe may be configured as separate supply pipes. Further, in the case where the cement milk (hardened material liquid) supply pipe and the water supply pipe are configured as separate supply pipes in this way, a multiple pipe such as a triple pipe that separates the cement milk (hardened material liquid) and water. Or a perforated tube may be used. Further, in the present embodiment, the inside of the injection rod 2 composed of the double pipe is the cement milk combined water supply passage 7, and the outside is the air supply passage 8, but the present invention is not limited to this and is composed of the double pipe. The inside of the injection rod 2 may be used as an air supply path, and the outside may be used as a cement milk combined water supply path.

The monitor 3 is attached to the tip of the injection rod 2 as described above. Inside the monitor 3, a cement milk combined water flow path 9 communicating with the cement milk combined water supply channel 7 of the injection rod 2 is formed in the axial direction, and injection is performed on the outer peripheral side of the cement milk combined water flow path 9. Four air flow paths 10 communicating with the air supply passage 8 of the rod 2 are formed in the axial direction (see FIGS. 3 and 12). The details of the air flow path 10 will be described later. In the present embodiment, the cement milk (hardened material liquid) flow path and the water flow path are configured as one flow path by using the cement milk combined water flow path 9, but the present invention is not limited to this, and the cement milk (hardened material) flow path is not limited to this. The liquid) flow path and the water flow path may be configured as separate flow paths.

The swivel 6 includes water, air, and cement milk supply hoses 14, 15, and 16, which are supplied from the water supply source 11, the air supply source 12, and the cement milk (hardening material liquid) supply source 13, respectively. It is connected and supplies water, air, and cement milk to the air supply path 8 provided in the injection rod 2 and the cement milk combined water supply path 7 (see FIG. 1). As described above, the water, air, and cement milk supplied from the water supply source 11, the air supply source 12, and the cement milk supply source 13, respectively, are the supply hoses 14, 15, 16 → swivel 6 → each. It is injected from a nozzle or the like via the supply paths 7 and 8 → each flow path 9 and 10. Here, water and cement milk are supplied to the cement milk combined water supply channel 7 from the water and cement milk supply hoses 14 and 16, respectively.

Next, the configurations of the injection rod 2 and the monitor 3 will be specifically described with reference to FIGS. 2 to 12. FIG. 2A is an external perspective view of a monitor equipped with a high-pressure injection nozzle device according to an embodiment of the present invention, and FIG. 2B is a diagram showing a coupling pin for connecting an injection rod and a monitor. 3 is a cross-sectional view taken along the line AA of FIG. 2, FIG. 4A is an enlarged view of the PP portion of FIG. 3, and FIG. 4B is a view showing a mounting hole for a nozzle body of the monitor. be. Here, in FIGS. 2A and 3, the upper side of the injection rod 2 is omitted.

As shown in FIG. 2A, the injection rod 2 is attached in combination with the monitor 3 as described above. The connection between the injection rod 2 and the monitor 3 will be described later. Here, as the injection rod 2, a double tube composed of an injection rod outer tube 17 having an outer diameter of 45 mm and an inner diameter of 37 mm and an injection rod inner tube 18 having an outer diameter of 24 mm and an inner diameter of 14 mm is used. The lower portion of the injection rod outer tube 17 has an inner diameter of 42 mm, a coupling pin insertion hole 19 is formed in the lower portion thereof, and a coupling pin injection rod recess 20a having substantially the same diameter as the semi-peripheral circumference of the coupling pin 36 is formed on the inner surface of the lower portion. (See FIG. 13). Further, the outer diameter of the injection rod inner pipe 18 is formed to be 22 mm from the upper end of the inner diameter 42 mm of the lower portion of the injection rod outer pipe 17 and slightly below. Further, the monitor 3 has a maximum outer diameter of 68 mm and a cement milk combined water flow path 9 having a diameter of 14 mm is formed inside the monitor 3, and the monitor 3 has a monitor outer tube 17a having an outer diameter of 42 mm and an inner diameter of 37 mm. A monitor inner tube 18a having an outer diameter of 24 mm and an inner diameter of 14 mm is formed, and an air flow path 10 is formed between the monitor outer tube 17a and the monitor inner tube 18a (see FIG. 3). The air flow path 10 is composed of a flow path between the monitor outer tube 17a and the monitor inner tube 18a, and four flow paths formed inside the monitor 3 communicating with the flow path (the air flow path 10). See FIG. 11). In this way, the air supply path 8 in the injection rod 2 and the air flow path 10 in the monitor 3 communicate with each other. As described above, a high-pressure injection nozzle device 1 for injecting cement milk and air is provided on the side surface of the monitor 3, and a coupling pin monitor recess 20b having a diameter substantially the same as the half outer circumference of the coupling pin 36 is formed on the upper portion of the side surface. (See FIG. 13). Further, a tip nozzle 4 for injecting water (liquid) is provided at the tip of the monitor 3. In the present embodiment, the injection rod 2 having a circular cross section having an outer diameter of about 45 mm is used, but the present invention is not limited to this, and an injection rod having a circular cross section having a diameter of about 50 mm to 140 mm (for example, about 75 mm) may be used. Further, when an injection rod having a circular cross section having a diameter of about 50 mm to 140 mm (for example, about 75 mm) is used, the inner diameter of the injection rod inner tube 18 may be 14 mm to 16 mm. Here, the inner diameter of the injection rod inner pipe 18 is determined by the flow rate of cement milk flowing in the injection rod inner pipe 18. Further, an injection rod having a hexagonal cross section may be used. Further, the coupling pin 36 is composed of a spring pin 36a and a spring pin 36b (see FIG. 2B). In this coupling pin 36, the spring pin 36b is first inserted into the coupling pin insertion hole 19 at the lower part of the injection rod 2, and then the spring pin 36a is press-fitted into the hollow portion of the spring pin 36b inserted into the coupling pin insertion hole 19. To.

As shown in FIG. 3, the high-pressure injection nozzle device 1 is formed with a material liquid injection nozzle 21 for injecting cement milk and an air injection nozzle 22 for injecting compressed air. Specifically, the material liquid injection nozzle 21 is provided inside the high-pressure injection nozzle device 1, and the air injection nozzle 22 is formed outside. In this way, when cement milk and compressed air are jetted from the high-pressure jet nozzle device 1 at high pressure, cement milk is jetted from the inside of the high-pressure jet nozzle device 1, and compressed air is jetted from the outside (outer peripheral portion) of the cement milk. By forming a gas phase film of compressed air around the jet of milk, the jet reach can be increased as compared with the case where there is no gas phase film of compressed air. Specifically, it will be described later.

The material liquid injection nozzle 21 is formed at the tip of the nozzle body 24 inserted into the nozzle body mounting hole 23 (see FIGS. 4 and 5). Here, as described above, two nozzle main body mounting holes 23 are formed at positions where the heights of the monitors 3 in the axial direction are different, at equal intervals on the circumference. In the present embodiment, it is assumed that two nozzle main body mounting holes 23 are formed at positions where the heights of the monitor 3 in the axial direction are different at equal intervals on the circumference, but the axial direction of the monitor 3 is formed. The heights of the above may not be different at equal intervals, and may not be formed at equal intervals on the circumference. Further, the number of the nozzle body mounting holes 23 does not have to be two, and a plurality of two or more (preferably four or more) such as three, four, and six, or one is formed. You may do it.

In this way, since a plurality of nozzle body mounting holes 23 are formed at positions where the heights of the monitors 3 in the axial direction are different, the nozzle body 24 can be mounted in different nozzle body mounting holes 23 according to the application. As a result, consolidated bodies of various shapes can be efficiently formed in a short time.

Further, the air injection nozzle 22 is formed from an outer peripheral surface of the nozzle body 24 and an inner peripheral surface of the air cover 25. Further, the air cover 25 is formed with six inclined grooves 25a having substantially the same shape and inclined in substantially the same direction diagonally toward the tip end on the inner peripheral surface (see FIG. 7). Specifically, the air cover 25 has a shape as shown in FIG. In FIGS. 9 (a) to 9 (m), the inclined groove 25a is inclined rearward from the surface (MM surface (see FIG. 8)) at the tip of the air cover 25, and the inside of the inclined groove 25a. It is a cross section of a surface (see FIG. 9) in which the position of the outermost point of the peripheral surface (outer apex of the inner peripheral surface) is inclined by 8 degrees (“twist angle”) in the circumferential direction. Specifically, the AA cross section of FIG. 8 corresponds to FIG. 9A, the BB cross section of FIG. 8 corresponds to FIG. 9B, and the CC cross section of FIG. 8 corresponds to FIG. 9 ( Corresponding to c) ... The KK cross section of FIG. 8 corresponds to FIG. 9 (k), the LL cross section of FIG. 8 corresponds to FIG. 9 (L), and the MM plane of FIG. 8 corresponds to FIG. It corresponds to FIG. 9 (m). That is, a surface in which the position of the outermost point (outer apex of the inner peripheral surface) of the inner peripheral surface of the inclined groove 25a is inclined by 8 degrees in the circumferential direction from FIG. 9 (m) of the MM surface of FIG. Is FIG. 9 (L) of the LL cross section, and the surface in which the position of the outermost point of the inner peripheral surface (outer apex of the inner peripheral surface) of the inclined groove 25a is inclined by 8 degrees in the circumferential direction is the view of the KK cross section. It becomes 9 (k). Here, "Φ15.5 mm", "Φ16.5 mm", "Φ17.6 mm" ... "Φ28.0 mm" in the upper part of FIG. 8 are the "tilted grooves 25a" in each cross section of the air cover 25 described above. It is the diameter of a circle whose radius is the line connecting the "outermost point of the inner peripheral surface (outer apex of the inner peripheral surface)" and the "center of the water flow path 9 for cement milk of the nozzle body 26" (see FIG. 9). Further, "Φ14.0 mm", "Φ14.1 mm", "Φ14.2 mm" ... "Φ15.4 mm" in the lower part of FIG. 8 are the "nozzle body 26" in each cross section of the air cover 25 described above. The diameter of the outer circumference. As described above, the maximum diameter of the hollow inner surface (including the inclined groove 25a) of the air cover 25 becomes smaller toward the tip, and the inclined groove 25a on the inner peripheral surface of the air cover 25 has a maximum width of 6 mm. It is formed in an arch shape and inclined in substantially the same direction at an angle of 42.85 degrees toward the tip (see FIG. 10). Here, the inclination angle in the oblique direction toward the tip of the inclined groove 25a of the air cover 25 is the rotation angle of the inclined groove 25a of the air cover 25 in the height direction (front-back direction) of the air cover 25 (FIG. 10). reference). That is, "an inclined line connecting" the outermost point of the inner peripheral surface on the tip side (outer apex of the inner peripheral surface) "and" the outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface) "" and " A line (length) on a plane connecting the "outermost point of the inner peripheral surface on the tip side of the inclined groove 25a (outer apex of the inner peripheral surface)" and the "outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface)". 16.7 mm) ”and“ a line in the height direction of the air cover 25 (height 18 mm of the air cover 25) from the outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface) ”. It is a rotation angle in the height direction (front-back direction) of the inclined groove 25a of the air cover 25 obtained from the above (see FIG. 10). Then, compressed air is injected from the air injection nozzle 22 at high speed from the air flow path 10 in the monitor 3 through the flow path whose cross-sectional area is reduced toward the tip. In this way, the compressed air injected from the air injection nozzle 22 of the air cover 25 covers the circumference of the cement milk injected from the nozzle body 24 as a swirling flow, as will be described later, so that the tip of the nozzle body 24 The cutting ability of the cement milk sprayed from the inner diameter portion is increased, and the cement milk can be sprayed to a longer distance. Here, FIG. 7A is a front perspective view of the air cover of the high-pressure injection nozzle device according to the embodiment of the present invention, and FIG. 7B is a rear perspective view of the air cover of the high-pressure injection nozzle device. 7 (c) is a rear view of the air cover of the high-pressure injection nozzle device, FIG. 7 (d) is a sectional view taken along the line DD of FIG. 7, and FIG. 8 is a side surface of the air cover of the high-pressure injection nozzle device. 9 is a sectional view taken along the line AA to MM in FIG. 8, FIG. 10 is a method for calculating the inclination angle of the inclined groove of the air cover of the air cover of the high-pressure injection nozzle device according to the embodiment of the present invention. It is a figure which shows. In the present embodiment, the air injection nozzle 22 is formed from the outer peripheral surface of the nozzle body 24 and the inner peripheral surface of the air cover 25, but the present invention is not limited to this, and the air flow path 10 in the monitor 3 is not limited to this. If it is a nozzle that communicates and is configured to surround the periphery of the outer diameter portion of the tip of the nozzle body 24, the cross-sectional area is reduced from the air flow path 10 in the monitor 3 toward the tip, and compressed air is injected at high speed. , Other forms of air injection nozzles may be used. Further, in the present embodiment, the inclined groove 25a on the inner peripheral surface of the air cover 25 is inclined by 42.85 degrees toward the tip end, but the present invention is not limited to this, and is not limited to this, and is approximately 26.49 degrees to approximately 46.68 degrees ( Preferably, it may be tilted obliquely within the range of about 30.33 degrees to about 42.85 degrees). Further, in the present embodiment, six inclined grooves 25a on the inner peripheral surface of the air cover 25 are provided, but the present invention is not limited to this, and four to eight (4 to six or six to eight) are provided. May be good. Further, in the present embodiment, the maximum width of the inclined groove 25a on the inner peripheral surface of the air cover 25 is set to 6 mm, but the maximum width is not limited to this, and may be 4 mm to 8 mm (preferably 5 mm to 7 mm). Further, in the present embodiment, the diameter of the tip of the air cover 25 is set to Φ15.5 mm, but the present invention is not limited to this, and when the amount of compressed air injected from the air injection nozzle 22 of the air cover 25 is increased, the air cover is used. A large air cover 25 may be used with a tip diameter of Φ15.5 mm to Φ21.5 mm (preferably Φ15.5 mm to Φ19.5 mm).

The nozzle body 24 is composed of a nozzle body 26 and a nozzle body extension 27 (see FIG. 5). Specifically, the nozzle body 26 has a cylindrical shape with a smaller diameter at the front portion and a cylindrical shape with a slightly larger diameter at the rear portion than the front portion. The hollow interior of the nozzle body 24 is composed of a rear end inner diameter portion 28, an intermediate inner diameter portion 29, and a tip inner diameter portion 30 (see FIG. 6). Here, FIG. 5 is a diagram showing components of the high-pressure injection nozzle device according to the embodiment of the present invention, FIG. 6 is a cross-sectional view of the components, and FIG. 11 is a sectional view taken along the line BB of FIG. Yes, FIG. 12 is a cross-sectional view taken along the line CC of FIG. The intermediate inner diameter portion 29 and the tip inner diameter portion 30 are formed in the nozzle body 26, and the rear end inner diameter portion 28 is formed in the nozzle body extension portion 27. Further, the rear end inner diameter portion 28 inside the nozzle body extension portion 27 is formed with a flow path dividing portion 31 that divides the cross section of the hollow rear end inner diameter portion 28 into a plurality of spaces (see FIG. 5).

The nozzle body support 32 is attached from the front outer peripheral surface of the nozzle body 26, has a circular tip outer peripheral surface, and has a male screw formed on the rear outer peripheral surface. Further, the air cover 25 has a hexagonal shape on the outer peripheral surface at the tip, and a male screw is formed on the outer peripheral surface at the rear (see FIG. 5). Further, as described above, the hollow interior of the air cover 25 has a tapered shape whose diameter is reduced toward the tip end, and an inclined groove 25a that is inclined in substantially the same direction diagonally toward the tip end is formed (see FIG. 6). ..

The cement milk supplied via the cement milk combined water supply pipe 7 in the injection rod 2 and the cement milk combined water flow path 9 in the monitor 3 is supplied to the nozzle body portion 24 in the order of the nozzle body extension portion 27 → the nozzle body 26. It is sent into the inside and is ejected from the material liquid injection nozzle 21 (see FIG. 11). Further, the compressed air supplied through the air supply path 8 in the injection rod 2 and the air flow path 10 in the monitor 3 is injected from the air injection nozzle 22 (see FIG. 11). Here, the air injection nozzle 22 communicates with the two air flow paths 10. As described above, the high-pressure injection nozzle device 1 in the present embodiment is composed of a nozzle body portion 24 including a nozzle body 26 and a nozzle body extension portion 27, a nozzle body portion support 32, and an air cover 25.

A differential pressure valve 34 is provided at the lower part of the monitor 3 (see FIG. 3). At the time of drilling, low-pressure water is supplied to the cement milk combined water flow path 7 of the injection rod 2, and this low-pressure water is ejected from the tip nozzle 4 via the differential pressure valve 34. When the cement milk is supplied to the cement milk combined water flow path 7 of No. 2, the differential pressure valve 34 is closed, and the cement milk is injected from the material liquid injection nozzle 21 (high pressure injection nozzle device 1).

Next, a method of assembling the injection rod 2, the monitor 3, and the high-pressure injection nozzle device 1 will be described with reference to FIGS. 13 and 14. Here, FIG. 13 is a diagram showing a method of assembling the high-pressure injection nozzle device and its peripheral equipment according to the embodiment of the present invention, and FIG. 14 is a diagram showing a method of mounting the high-pressure injection nozzle device.

As shown in FIG. 13, the lower end of the injection rod 2 is first inserted from the upper part of the monitor upper tube 35. When inserting the injection rod 2, a semi-circular injection rod protrusion 44 formed at the lower end of the injection rod outer tube 17 and a semi-circular monitor upper tube inner protrusion 45 formed at the upper part of the monitor upper tube 35 are formed. By fitting, the monitor upper tube 35 and the injection rod 2 are aligned in the circumferential direction and attached. Then, the coupling pin 36 is inserted from the coupling pin insertion hole 19 at the bottom of the injection rod 2, and the coupling pin 36 is inserted into the coupling pin injection rod recess 20a at the bottom of the injection rod inner tube 18 and the coupling pin monitor recess 20b at the top of the monitor upper tube 35. By fitting, the monitor 3 is coupled to the injection rod 2. In the present embodiment, the upper part and the lower part of the upper end of the air flow path 10 formed in the four pieces in the monitor upper pipe 35 have been described as one, but the present invention is not limited to this, and four pieces in the monitor upper pipe 35 are formed. The upper part and the lower part of the upper end of the air flow path 10 may be configured as separate bodies. By configuring as a separate body in this way, it becomes easy to form the four air flow paths 10 in the monitor upper pipe 35.

Next, the high-pressure injection nozzle device 1 is attached to the nozzle main body attachment hole 23 formed on the side surface of the monitor upper tube 35 (see FIG. 14). Specifically, the high-pressure injection nozzle device 1 is attached to the nozzle main body attachment hole 23 of the monitor upper tube 35 by the following procedures (1) to (3).

(1) The nozzle body extension portion 27 is inserted into the nozzle body portion mounting hole 23. As a result, the nozzle body extension portion 27 is fitted into the nozzle body portion mounting hole 23.

(2) Next, the nozzle body support 32 is fitted from the tip direction of the nozzle body 26, and is inserted into the nozzle body mounting hole 23 in that state. When the nozzle body support 32 is inserted into the nozzle body mounting hole 23, it is formed in the male screw formed on the outer periphery of the rear end of the nozzle body support 32 and in the nozzle body mounting hole 23 of the monitor 3. By screwing the female screw, the nozzle body support 32 (including the nozzle body 26 and the nozzle body extension 27) is attached to the monitor 3. The nozzle body extension portion 27 attached in this way is projected and attached into the cement milk combined water flow path 9 (hardened material liquid flow path) in the monitor 3 (see FIG. 4). In the present embodiment, the nozzle body extension 27 is attached so as to project into the cement milk combined water flow path 9 (hardened material liquid flow path) in the monitor 3, but the cement milk combined water flow path of the monitor 3 is preferable. It is preferable to project the 9 (curing material liquid flow path) to the substantially center of the mounting.

(3) Next, the air cover 25 is fitted from the tip of the nozzle body 26, and the male screw formed on the outer periphery of the air cover 25 and the female screw formed in the air cover mounting hole 43 on the inner circumference of the side surface of the monitor 3 are inserted. By screwing, the air cover 25 is attached to the monitor 3.

Next, a monitor lower pipe 39 having a differential pressure valve 34 built in the lower part of the monitor upper pipe 35 is attached. Specifically, the monitor lower tube 39 is attached to the monitor upper tube 35 by screwing the male screw on the upper outer circumference of the monitor lower tube 39 and the female screw on the lower inner circumference of the monitor upper tube 35.

In this way, the rear end inner diameter portion 28 of the nozzle body portion 24 is provided so as to project into the cement milk combined water flow path 9 (hardened material liquid flow path) of the monitor 3, so that the linear distance inside the nozzle body portion 24 is sufficiently long. It can be secured, the generation of turbulent flow of cement milk flowing in the nozzle main body 24 can be reduced, and the cutting ability of the cement milk ejected from the tip of the nozzle main body 24 is increased, so that the ground can be secured. It can destroy the tissue structure and inject cement milk over long distances. Further, since the total cross-sectional area of the flow path divided by the flow path dividing portion 31 has a shape that occupies 40% of the hollow cross-sectional area of the rear end inner diameter portion 28 near the flow path dividing portion 31, the nozzle main body. Since the cement milk flowing through the rear end inner diameter portion 28 of the portion 24 is divided into the respective spaces divided by the flow path dividing portion 31 and sent toward the tip while being compressed by an appropriate compressive force, the cement milk is divided into the flow path. It is possible to finely stratify while increasing the speed in each space divided by the portion 31, and by increasing the cutting ability of the cement milk ejected from the material liquid injection nozzle 21 at the tip of the nozzle body 24, the cutting ability is increased. It can destroy the tissue structure of the ground and inject cement milk over longer distances. In the present embodiment, the total cross-sectional area of the flow path divided by the flow path dividing portion 31 is set to occupy 40% of the hollow cross-sectional area of the rear end inner diameter portion 28 in the vicinity of the flow path dividing portion 31. Not limited to this, it may have an area of 2% to 20% of the hollow cross-sectional area of the rear end inner diameter portion 28 in the vicinity of the flow path dividing portion 31.

Further, since the cement milk flowing through the rear end inner diameter portion 28 of the nozzle main body portion 24 is divided into the respective spaces divided by the flow path dividing portion 31 and sent toward the tip end, the cement milk is divided by the flow path dividing portion 31. It is possible to make the layer flow more finely in each of the created spaces, and by increasing the cutting ability of the cement milk injected from the material liquid injection nozzle 21 at the tip of the nozzle body 24, the structure of the ground is destroyed. Cement milk can be sprayed over longer distances. As a result, by increasing the cutting ability of the cement milk ejected from the material liquid injection nozzle 21 at the tip of the nozzle main body 24, the tissue structure of the ground can be destroyed and the cement milk can be ejected to a longer distance.

As described above, the male screw formed on the outside of the outer peripheral surface of the nozzle body support 32 and the female screw formed on the inner peripheral surface of the nozzle body mounting hole 23 of the monitor 3 are screwed together to form the nozzle body. Since the portion 24 is detachably attached to the monitor 3, the nozzle main body portion 24 can be freely replaced according to the soil quality and the like, and the nozzle main body portion 24 can be attached to the monitor 3 by a simple method.

Next, a construction procedure using a ground improvement device equipped with a monitor equipped with a high-pressure injection nozzle device according to an embodiment of the present invention will be briefly described.

First, after positioning the injection rod 2 at a position to be excavated, water (liquid) is ejected from the tip nozzle 4 of the injection rod 2 at that position to drill a hole to a predetermined depth. Then, after the holes are drilled to a predetermined depth, cement milk is injected from the material liquid injection nozzle 21 and compressed air is injected from the air injection nozzle 22 while swinging the injection rod 2. Specifically, the injection rod 2 is swung by 30 degrees (predetermined angle) while injecting cement milk together with compressed air from the injection nozzles (material liquid injection nozzle 21, air injection nozzle 22). In the present embodiment, since the inclined groove 25a is formed on the inner peripheral surface of the air cover 25 so as to be inclined in substantially the same direction diagonally toward the tip end, the space between the air cover 25 and the outer peripheral side of the nozzle body 24 is formed. The compressed air jetted from the tip swirls around the cement milk jetted from the nozzle body 24. As a result, the cutting ability of the cement milk ejected from the tip of the nozzle main body 24 is increased, so that the tissue structure of the ground is destroyed and the cement milk can be ejected to a longer distance (see FIG. 15). That is, the compressed air jetted from the tip between the air cover 25 and the outer peripheral side of the nozzle body 24 swirls while covering the area around the cement milk jetted from the nozzle body 24 without any gaps. The cement milk jetted from the tip of the nozzle is pressed toward the center by the compressed air swirling around it, and the jet of cement milk immediately after the jet of the cement milk jetted from the tip of the nozzle body 24 greatly increases in the radial direction. It becomes difficult and the speed of cement milk can be maintained. In addition, since the ground around the swirling flow is pressed and cut by the swirling flow of compressed air swirling around the cement milk, the compressed air around the cement milk jet flow can be included without gaps, and the air layer should be thickened. Can be done. In this way, the jet of cement milk immediately after the jet of cement milk jetted from the tip of the nozzle body 24 is unlikely to increase significantly in the radial direction, so that the straightness of the jet of cement milk can be increased and the nozzle can be increased. Since the compressed air layer around the cement milk jet immediately after injection from the main body 24 can be thickened, the ground around the cement milk jet immediately after injection from the nozzle main body 24 is the flow of the cement milk jet. Obstacles can also be reduced. As a result, the region (potential core region) in which the speed of the cement milk ejected from the nozzle main body 24 does not decrease can be lengthened, and the cement milk can be ejected to a longer distance. Further, even if a cavity (air bubble) due to cavitation exists in the peripheral portion of the cement milk jetted from the nozzle body 24, the compressed air jetted from between the air cover 25 and the outer peripheral side of the nozzle body 24 is cement. Since it swirls around the milk without any gaps, it becomes difficult for the cement milk to come into contact with the ground, and it is possible to prevent the cavities existing around the cement milk from collapsing. As a result, the region where the speed of the cement milk ejected from the nozzle main body does not decrease (potential core region) can be made longer, and the cement milk can be ejected to a longer distance. That is, when the compressed air is jetted straight from between the air cover 25 and the outer peripheral side of the nozzle main body 24, the cement milk cannot be surrounded by the compressed air without any gaps. The non-inclusive part of the air is more likely to come into contact with the ground, and the cement milk comes into contact with the surrounding ground, causing the cavity to collapse. Then, since the momentum of the cement milk is reduced due to the large impact force at the time of the collapse of the cavity, the potential core region cannot be made longer and the cement milk cannot be ejected to a longer distance. In this way, the compressed air injected from between the air cover 25 and the outer peripheral side of the nozzle main body 24 swirls while covering the area around the cement milk without any gaps, so that the cement milk does not easily come into contact with the ground and the cement is cemented. Since the collapse of the cavity generated in the peripheral part of the milk can be prevented, the region where the speed of the cement milk ejected from the nozzle body 24 does not decrease (potential core region) can be made longer, and the cement milk can be made more. It can be sprayed over a long distance. Here, the potential core region is a region in which the speed of the cement milk jetted from the nozzle main body 24 does not decrease, and in this potential core region, the jet pressure at the outlet of the material liquid injection nozzle 21 is maintained as it is. So to speak, it forms the core of the jet, and the spread of the diameter of the cement milk jet jet jetted from the material liquid jet nozzle 21 is small (see FIG. 15). Here, FIG. 15 is a diagram showing an injection state from the tip nozzle of the high-pressure injection nozzle device according to the embodiment of the present invention.

Next, with the injection rod 2 swung 30 degrees, the injection rod 2 is pulled up by a predetermined length (for example, 10 cm or less (preferably 5.0 cm (preferably 2.5 cm))). Until the injection from the injection nozzles (material liquid injection nozzle 21, air injection nozzle 22) is completed, clockwise rocking injection → injection rod 2 pulling up → counterclockwise rocking injection → injection rod 2 pulling up → clockwise Swing injection → The injection rod 2 is repeatedly pulled up. In this embodiment, the injection rod 2 is swung, but the injection rod 2 is rotated in one direction (clockwise rotation or counterclockwise rotation is possible). You may let me.

Next, the injection rod 2 is pulled up from the excavation hole by a crane or the like and is extracted from the excavation hole. By doing so, a fan-shaped consolidated body is created in the ground.

Next, a modification will be described.

(Modification 1)
The difference between this embodiment and the first modification is that in the present embodiment, the position of the outermost point (outer apex of the inner peripheral surface) of the inclined groove 25a of the air cover 25 is rotated by 8 degrees (“twist angle”). The cross section (AA cross section to MM plane (see FIG. 8)) is shown in FIGS. 9 (a) to 9 (m), and the inclination angle (air cover) of the inclined groove 25a of the air cover 25 is shown. An angle that inclines diagonally toward the tip of the inner peripheral surface of 25, "42.85 degrees") was obtained. (See FIG. 8)) uses the air cover 25 in which the position of the outermost point (outer apex of the inner peripheral surface) of the inner peripheral surface of the inclined groove 25a of the air cover 25 is rotated by 4 degrees (“twist angle”). The inclination angle of the inclined groove 25a of the air cover 25 (the angle inclined toward the tip of the inner peripheral surface of the air cover 25, "42.85 degrees") has just been obtained. That is, the inclination angle of the inclined groove 25a of the air cover 25 of the first modification is smaller than the inclination angle of the inclined groove 25a of the air cover 25 in the present embodiment.

The air cover 25 has a shape as shown in FIG. In FIGS. 16A to 16M, the inclined groove 25a is inclined rearward from the surface (MM surface (see FIG. 8)) at the tip of the air cover 25, and the inner circumference of the inclined groove 25a is inclined. It is a cross section of a surface (see FIG. 16) in which the position of the outermost point (outer apex of the inner peripheral surface) is inclined by 4 degrees in the circumferential direction. Specifically, the AA cross section of FIG. 8 corresponds to FIG. 16A, the BB cross section of FIG. 8 corresponds to FIG. 16B, and the CC cross section of FIG. 8 corresponds to FIG. Corresponding to c) ... The KK cross section of FIG. 8 corresponds to FIG. 16 (k), the LL cross section of FIG. 8 corresponds to FIG. 16 (L), and the MM plane of FIG. 8 corresponds to FIG. It corresponds to FIG. 16 (m). That is, a surface in which the position of the outermost point (outer apex of the inner peripheral surface) of the inner peripheral surface of the inclined groove 25a is inclined 4 degrees in the circumferential direction from FIG. 16 (m) of the MM surface of FIG. Is FIG. 16 (L) in the LK cross section, and the surface in which the position of the apex of the inclined groove 25a is inclined by 4 degrees in the circumferential direction is shown in FIG. 16 (k) in the KK cross section. Here, FIG. 16 is a cross-sectional view taken along the line AA to a cross-sectional view taken along the line AM of FIG. 8 in the modified example 1 of the present invention.

As described above, the inclination angle in the oblique direction toward the tip of the inclined groove 25a of the air cover 25 is the rotation angle of the inclined groove 25a of the air cover 25 in the height direction (front-back direction) of the air cover 25 (front-back direction). See FIG. 10). That is, "an inclined line connecting" the outermost point of the inner peripheral surface on the tip side (outer apex of the inner peripheral surface) "and" the outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface) "" and " A line (length) on a plane connecting the "outermost point of the inner peripheral surface on the tip side of the inclined groove 25a (outer apex of the inner peripheral surface)" and the "outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface)". 10.53 mm) ”and“ a line in the height direction of the air cover 25 (height 18 mm of the air cover 25) from the outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface) ”. It is a rotation angle in the height direction (front-back direction) of the inclined groove 25a of the air cover 25 obtained from the above (see FIG. 17). As described above, when the inclination angle of the inclined groove 25a on the inner peripheral surface of the air cover 25 is obtained by the same method as in the present embodiment, the inclination angle becomes 30.33 degrees, and the air cover 25 is directed toward the tip end direction. The shape is formed by inclining an arch shape at an angle of 30.33 degrees in substantially the same direction (see FIG. 17). Here, FIG. 17 is a diagram showing a method of calculating the inclination angle of the inclination groove of the air cover of the high-pressure injection nozzle device according to the first modification of the present invention.

Cross section (AA cross section to M-) where the position of the outermost point (outer apex of the inner peripheral surface) of the inclined groove 25a of the air cover 25 is rotated by 8 degrees (“twist angle”) in the circumferential direction. The M surface (see FIG. 8)) is shown in FIGS. 9 (a) to 9 (m), and the inclination angle of the inclined groove 25a in that case (inclined diagonally toward the tip toward the inner peripheral surface of the air cover 25). The angle) is 42.85 degrees, and the position of the outermost point (outer apex of the inner peripheral surface) of the inner peripheral surface of the inclined groove 25a of the air cover 25 is in the circumferential direction on the AA cross section to the MM surface of FIG. FIG. 16 shows a case where the cross section is rotated by 4 degrees (“twist angle”), and the inclination angle of the inclined groove 25a of the air cover 25 in this case is 30.33 degrees. Further, in the same manner, the cross section from the AA cross section to the MM surface of FIG. 8 where the position (“twist angle”) of the inclined groove 25a of the air cover 25 is rotated by 1 to 15 degrees in the circumferential direction. Is shown in FIG. In this way, when the AA cross section to the MM surface of FIG. 8 is a cross section where the position of the inclined groove 25a (“twist angle”) of the air cover 25 is rotated once in the circumferential direction, “ The length of the line on the plane connecting the "outermost point of the inner peripheral surface on the tip side of the inclined groove 25a (outer apex of the inner peripheral surface)" and the "outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface)". When the inclination is 6.62 mm, the inclination angle of the inclined groove 25a is 20.19 degrees, and the cross section is rotated twice in the circumferential direction, "the innermost surface on the tip side of the inclined groove 25a". The length of the line on the plane connecting the "outer point (outer apex of the inner peripheral surface)" and the "outermost point of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface)" is 7.60 mm, and the inclination groove 25a is inclined. The angle is 22.89 degrees ... When the cross section is rotated by 15 degrees in the circumferential direction, it is "the outermost point of the inner peripheral surface on the tip side of the inclined groove 25a (outer apex of the inner peripheral surface)". The length of the line on the plane connecting the "outermost points of the inner peripheral surface on the rear end side (outer apex of the inner peripheral surface)" is 21.75 mm, and the inclination angle of the inclined groove 25a is 50.39 degrees. Of these, when the air cover 25 having a twist angle of the inclined groove 25a around 4 to 8 degrees in the circumferential direction was used, cement milk could be sprayed to a longer distance from the experimental results (numerical analysis). Therefore, the inclination angle of the inclined groove 25a on the inner peripheral surface of the air cover 25 is within the range of about 26.49 degrees to about 46.68 degrees (preferably about 30.33 degrees to about 42.85 degrees). It is preferable to have. Here, FIG. 18 is a diagram showing various inclination angles of the inclined groove of the air cover in the modified example 1 of the present invention.

(Modification 2)
The difference between the present embodiment and the modified example 2 is that in the present embodiment, six inclined grooves 25a are provided on the inner peripheral surface of the air cover 25, and the air cover 25 and the nozzle main body are provided on the nozzle main body support 32. With the 24 mounted, the outermost point (inside) of the inner peripheral surface of the inclined groove 25a of the air cover 25 from the center of the cement milk combined water flow path (hardened material liquid flow path) 9 on the rear end side side surface of the nozzle body 24. The ratio (0.628) of the air opening (opening between the air cover 25 and the nozzle body 24) on the rear end side side surface of the air cover 25 to the circle whose diameter (20 mm) is the line connecting the outer apex of the peripheral surface). ) Was obtained, but in the modified example 2, the inclined grooves 25a on the inner peripheral surface of the air cover 25 were set to 4, 6, and 8 and the water flow path for cement milk (cured) on the rear end side side surface of the nozzle body 24. After the air cover 25 for a circle whose diameter (20 mm to 40 mm) is a line connecting the center of the material liquid flow path 9 to the outermost point (outer apex of the inner peripheral surface) of the inclined groove 25a of the air cover 25. The difference is that the ratio of the air opening (opening between the air cover 25 and the nozzle body 26) on the side surface on the end side is obtained. Here, FIG. 19 is a diagram showing the opening ratio of the side surface on the rear end side of the air cover of the high-pressure injection nozzle device in the second modification of the present invention.

As shown in FIG. 19A, when the air cover 25 and the nozzle body 26 are mounted on the nozzle body support 32, the side cross sections of the air cover 25 on the rear end side are “nozzle body portions” from the center. 24 tip inner diameter part 30 (white part in the center) ”→“ Nozzle body part 24 component part (“hatching part”) ”→“ Air cover 25 opening (white part) ”→“ Air cover 25 component part (Hatching) ”. The opening ratio of the rear end side side surface of the air cover 25 is "(area of the opening of the air cover 25) / (" outermost point of the inner peripheral surface of the inclined groove 25a (outer apex of the inner peripheral surface) "". It can be obtained by the area of a circle whose radius is the line connecting the center of the water flow path 9 for cement milk of the nozzle body 26). When the air cover 25 has four inclined grooves 25a, the "opening ratio of the side surface on the rear end side of the air cover" is 0.623 (Φ20), 0.532 (Φ28), 0.421 (Φ40). In the case of 6 inclined grooves, the "opening ratio of the side surface on the rear end side of the air cover" is 0.628 (Φ20), 0.534 (Φ28), 0.422 (Φ40), and in the case of 8 inclined grooves. The "opening ratio of the side surface on the rear end side of the air cover" is 0.641 (Φ20), 0.539 (Φ28), and 0.423 (Φ40). From this, the opening on the rear end side of the inclined groove 25a of the air cover 25 is the air cover 25 from the substantially center of the curing material liquid flow path of the nozzle body 26 with the nozzle body 26 and the air cover 25 attached. It can be said that it is approximately 42.1% to approximately 64.1% with respect to the circle whose diameter is the length to the maximum outer portion on the rear end side of the inclined groove 25a.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. Furthermore, the scope of the present invention is shown by the description of the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 High-pressure injection nozzle device 2 Injection rod 3 Monitor 4 Tip nozzle 5 Working machine 6 Swivel 7 Cement milk combined water supply channel 8 Air supply channel 9 Cement milk combined water channel 10 Air channel 11 Water source 12 Air supply source 13 Cement milk source 14 Water supply hose 15 Air supply hose 16 Cement milk supply hose 17 Injection rod outer pipe 17a Monitor outer pipe 18 Injection rod inner pipe 18a Monitor inner pipe 19 Coupling pin insertion hole 20a Coupling pin Injection rod recess 20b Coupling pin Monitor recess 21 Material liquid injection nozzle 22 Air injection nozzle 23 Nozzle body mounting hole 24 Nozzle body 25 Air cover 25a Inclined groove 26 Nozzle body 27 Nozzle body extension 28 Rear end inner diameter 29 Intermediate inner diameter 30 Tip inner diameter 31 Flow Path division 32 Nozzle body support 34 Differential pressure valve 35 Monitor upper tube 36 Coupling pin 36a Spring pin 36b Spring pin 37 Injection rod inner tube connection tube 38 Nozzle body extension fastening convex part 39 Monitor lower tube 40 Flow path closure 41 Nozzle body mounting hole closure 42 Air flow path closure 43 Air cover mounting hole 44 Injection rod protrusion 45 Monitor upper pipe protrusion 46 O-ring 47 O-ring mounting recess

Claims (6)

A high-pressure injection nozzle device provided on the side surface of a monitor that communicates with the inside of a curing material liquid supply pipe formed in the injection rod in the axial direction and is connected to the tip of the injection rod.
A tip that communicates with the tapered intermediate inner diameter portion formed by reducing the inner peripheral surface toward the tip and the tip of the intermediate inner diameter portion, and whose diameter is substantially the same as the diameter of the tip of the intermediate inner diameter portion. A rear end formed by communicating with the inner diameter portion and the rear end of the intermediate inner diameter portion and having a diameter substantially the same as the diameter of the rear end of the intermediate inner diameter portion, or expanding from the substantially same diameter toward the rear end. The nozzle body, which has a hollow hardener liquid flow path consisting of an inner diameter,
It has an air cover in which a plurality of inclined grooves inclined in substantially the same direction diagonally toward the tip end are formed on the inner peripheral surface, and a compressed air flow path is formed between the inner peripheral surface and the outer peripheral side of the nozzle body. ,
The compressed air jetted from the tip between the air cover and the outer peripheral side of the nozzle body covers the curing material liquid sprayed from the tip of the nozzle body as a swirling flow, so that the nozzle body A high-pressure injection nozzle device characterized in that the cutting ability of the hardened material liquid sprayed from the inner diameter of the tip is increased and the hardened material liquid is sprayed to a longer distance. The high-pressure injection nozzle device according to claim 1, wherein the inclined grooves of the air cover are formed on the inner peripheral surface of the air cover in a range of 4 to 8 and having substantially the same shape. 2. The high pressure injection nozzle device described. The opening on the rear end side of the inclined groove of the air cover is the inclined groove of the air cover from the substantially center of the curing material liquid flow path of the nozzle main body with the nozzle main body and the air cover attached. The high-pressure injection nozzle device according to claim 3, wherein the diameter is approximately 42.1% to approximately 64.1% with respect to a circle having a diameter up to the maximum outer portion on the rear end side. A flow path dividing portion for dividing the hollow cross section into a plurality of spaces is formed in the rear end inner diameter portion of the nozzle body portion.
The flow path dividing portion is located at substantially the center of the hollow-shaped rear end inner diameter portion in the vicinity of the flow path dividing portion, and is 2% to 20% of the hollow shape cross-sectional area of the rear end inner diameter portion in the vicinity of the flow path dividing portion. Has a portion with an area of%
After the curing material liquid flowing through the inner diameter of the rear end of the nozzle body is laminarized more finely in each space divided by the flow path dividing portion, the hollow shape in which the tangible material of the intermediate inner diameter does not exist. Since the diameter is reduced in space and sent toward the tip, the cutting ability of the hardened material liquid sprayed from the inner diameter of the tip of the nozzle body is increased, and the hardened material liquid can be sprayed to a longer distance. The high-pressure injection nozzle device according to claim 1. A ground improvement device provided with the high-pressure injection nozzle device according to any one of claims 1 to 5, which is mounted on the monitor.

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