JP2020169485A - Air excavator - Google Patents

Abstract

To provide an air excavator that can suppress the scattering of earth and sand and improve workability and safety.SOLUTION: An air excavator according to the embodiment is an air excavator for excavating by passing compressed air inside a tubular injection nozzle and injecting compressed air, and comprises an additional nozzle 10 attached to a tip of the injection nozzle. The additional nozzle 10 has a plurality of injection holes 12h for injecting compressed air to the outside.SELECTED DRAWING: Figure 5

Description

The present invention relates to an air excavator that excavates with air.

An air excavator that excavates by injecting compressed air is known. For example, Patent Document 1 describes an excavator that excavates by injecting high-pressure air. The excavator comprises an outer steel pipe and an inner pipe connected to an air hose via a valve and an open / close lever. The air hose is connected to the air compressor, and when the open / close lever is opened, high-pressure air is supplied from the air compressor to the inner pipe via the high-pressure air hose.

On the opposite side of the inner pipe and the outer steel pipe from the high pressure air hose, a tip continuous with the outer steel pipe is attached. An opening for ejecting high-pressure air is formed at the tip. High-pressure air passes through the inside of the inner pipe and is ejected from the opening to the outside of the outer steel pipe. Excavation of earth and sand is performed by hitting the earth and sand with the high-pressure air ejected in this way. A cap-shaped dustproof cover is attached by an adjusting screw near the tip of the outer steel pipe.

Patent Document 2 describes a pneumatic earth and sand treatment apparatus. The pneumatic earth and sand treatment device is provided with an underground insertion pipe having an injection nozzle attached to the tip, and the underground insertion pipe is connected to the compressor via an air supply pipe. A ball cock with a rotary lever is interposed between the underground insertion pipe and the air supply pipe, and the underground insertion pipe is opened and closed by rotating the lever of the ball cock.

An injection nozzle is attached to the end of the underground insertion pipe opposite to the air supply pipe, and the injection nozzle is inserted into the ground by screwing the male screw of the underground supply pipe into the female screw of the injection nozzle. Can be attached to. The injection nozzle has a cylindrical shape, and a reduced diameter hole extending in the axial direction of the injection nozzle is formed in the center of the injection nozzle. The diameter of the reduced diameter hole is smaller than the inner diameter of the underground intubation, and the air from the compressor is injected to the outside through the underground insertion tube and the reduced diameter hole. In this way, it is possible to excavate earth and sand by injecting air from the compressor into the ground through the diameter-reduced holes. Further, in the vicinity of the injection nozzle of the underground insertion pipe, there is a support portion supported on the outer peripheral surface of the underground insertion pipe, and a tapered tubular cap portion whose diameter is expanded radially outward from the support portion and toward the injection nozzle side. Is provided.

Utility Model Registration No. 3157239 Japanese Unexamined Patent Publication No. 2006-22547

When a cap is provided on the tip end side of the tubular member as in the excavation device and the pneumatic earth and sand treatment device described above, it is possible to suppress the scattering of earth and sand due to the ejection of high-pressure air by the cap. However, from the viewpoint of an operator who holds a tubular member and performs excavation work, the cap is provided in front of the high-pressure air ejection hole passing through the tubular member, so that the cap portion interferes with the high-pressure air ejected from the ejection hole. I can't see it. Therefore, there is a problem that the workability of the excavation work is not good because it is not possible to visually recognize where the high-pressure air is applied because the shade part becomes an obstacle.

On the other hand, if the cap portion is removed from the tubular member, there is a problem that the scattering of earth and sand cannot be suppressed. Specifically, as described above, the hole through which air passes is formed in the center of the tubular member so as to extend in the axial direction of the tubular member. That is, in the above-mentioned inner pipe and injection nozzle, one hole is formed in the center, and air is concentrated from one hole formed in the center to inject air at a high pressure. Therefore, when air is injected, the earth and sand are scattered over a wide area, and there is a concern that the soaring earth and sand may obstruct the view of the worker or the worker may suck the earth and sand. Furthermore, there is a concern that the environment around the construction site may be damaged by scattering the earth and sand scattered over a wide area to the outside of the construction site.

An object of the present invention is to provide an air excavator capable of suppressing the scattering of earth and sand and improving workability and safety.

The air excavator according to one aspect of the present invention is an air excavator that allows compressed air to pass through the inside of a tubular injection nozzle and injects compressed air for excavation, and is attached to the tip of the injection nozzle. The additional nozzle is provided, and the additional nozzle has a plurality of injection holes for injecting compressed air to the outside.

This air excavator is provided with a tubular injection nozzle, and an additional nozzle is further attached to the tip of the injection nozzle. This additional nozzle has a plurality of injection holes for injecting compressed air to the outside. Therefore, by dispersing the compressed air passing through the inside of the injection nozzle in a plurality of injection holes, it is possible to prevent the compressed air from concentrating in one injection hole. Therefore, since the compressed air dispersed from each of the plurality of injection holes is injected, it is possible to reduce the scattering of earth and sand and the like due to the injection of the compressed air. As a result, it is possible to prevent the earth and sand from being scattered over a wide area, so that it is possible to eliminate the situation where the earth and sand obstruct the view of the worker or the worker sucks the earth and sand. Further, since it is possible to suppress the scattering of earth and sand over a wide range, it is possible to suppress the scattering of earth and sand to the outside of the construction site, and it is possible to suppress the possibility of damaging the environment around the construction site. Further, since the scattering of earth and sand over a wide range is suppressed, the above-mentioned shade portion can be eliminated. Therefore, since the cap portion does not get in the way, it is possible to avoid a situation in which the cap portion obstructs the view and interferes with the work, and the work can be performed while visually recognizing the compressed air from the injection hole. As a result, the workability and safety of the excavation work can be improved.

The air excavator according to another aspect of the present invention is an air excavator that allows compressed air to pass through the inside of a tubular injection nozzle and injects compressed air for excavation, and is attached to the tip of the injection nozzle. The additional nozzles are provided with a flat injection hole that injects compressed air to the outside and extends long in one direction.

In this air excavator, an additional nozzle is further attached to the tip of the injection nozzle, and the additional nozzle has a flat injection hole that injects compressed air to the outside and extends long in one direction. Therefore, the compressed air passing through the inside of the injection nozzle is injected to the outside from the flat injection hole extending in one direction, and the cross-sectional area of the injection hole through which the compressed air passes can be widened, so that the compressed air to the injection hole can be widened. Can suppress the concentration of air. Therefore, since the compressed air is injected from the flat injection hole extending in one direction, it is possible to suppress the scattering of earth and sand and the like accompanying the injection of the compressed air. As a result, as with the air excavator according to one aspect described above, it is possible to suppress the scattering of earth and sand over a wide area, and the earth and sand obstruct the view of the worker or the worker sucks the earth and sand. It is possible to suppress the possibility of damaging the surrounding environment of the construction site. Further, since it is possible to suppress the scattering of earth and sand over a wide range, the above-mentioned shade portion can be eliminated. Therefore, it is possible to prevent the shade from obstructing the view of the worker, and the worker can perform the work while visually recognizing the compressed air from the injection hole, thereby improving the workability and safety of the excavation work. be able to.

Further, the additional nozzle may be detachable from the injection nozzle. In this case, when the additional nozzle is clogged, the additional nozzle can be removed and the additional nozzle can be cleaned. Further, since the additional nozzles can be easily replaced, it is possible to easily replace the additional nozzles with other types when different types of additional nozzles are prepared.

In addition, a female screw is formed on the inner peripheral surface of the tip of the injection nozzle, the additional nozzle is provided with a male screw that screwes with the female screw on the outer circumference, and the additional nozzle has the male screw screwed into the female screw. By doing so, it may be made removable with respect to the injection nozzle. In this case, since the male screw on the outer peripheral surface of the additional nozzle is screwed to the female screw on the inner peripheral surface of the injection nozzle, it is possible to suppress the enlargement of the diameter of the injection nozzle and the additional nozzle. Further, since the additional nozzle can be attached by screwing the male screw of the additional nozzle into the female screw of the injection nozzle, the additional nozzle can be easily attached to and detached from the injection nozzle.

Further, the additional nozzle may have a groove portion recessed from the tip surface of the additional nozzle located on the opposite side of the injection nozzle. In this case, when the tip surface of the additional nozzle is pressed against the earth and sand, a gap is formed between the groove and the earth and sand. Therefore, the compressed air injected from the additional nozzle to the earth and sand or the like is dispersed and discharged through the voids, so that the pressure of the compressed air injected from the injection hole can be dispersed. Therefore, it is possible to more reliably suppress the scattering of earth and sand due to the injection of compressed air.

Further, the additional nozzle has a plurality of injection holes, and the plurality of injection holes may be opened on the bottom surface of the groove portion. In this case, when the tip surface of the additional nozzle is pressed against earth and sand, a gap is formed between each of the plurality of injection holes opened on the bottom surface of the groove and the earth and sand. Therefore, since the compressed air injected from the additional nozzle into the earth and sand is injected into the earth and sand through the voids, the pressure of the compressed air injected into the earth and sand can be suppressed. Therefore, the scattering of earth and sand can be suppressed more reliably.

Further, the groove portion extends from one end to the other end of the tip surface, and the plurality of injection holes may be dispersedly arranged on the bottom surface of the groove portion. In this case, since the groove extends from one end to the other end of the tip surface, the compressed air from the injection hole is released to one end and the other end of the tip surface through the groove, so that the compressed air to be injected is concentrated. Can be suppressed. Further, since a plurality of injection holes are dispersedly arranged on the bottom surface of the groove, compressed air can be dispersed and injected from each of the plurality of injection holes. Therefore, it is possible to more reliably suppress the scattering of earth and sand due to the injection of compressed air.

Further, the additional nozzle has a plurality of injection holes, and the plurality of injection holes may be arranged in a circular shape on the tip surface of the additional nozzle located on the opposite side of the injection nozzle. In this case, since the compressed air is injected from each of the plurality of injection holes arranged in a circular shape, the dispersed compressed air can be injected from each injection hole. As a result, the scattering of earth and sand can be suppressed more reliably.

According to the present invention, it is possible to suppress the scattering of earth and sand and improve workability and safety.

It is a figure which shows the example of the construction site where the excavation work which uses the air excavator which concerns on 1st Embodiment is performed. It is a side view which shows the pipe part of the air excavator of FIG. FIG. 5 is a side view of an exemplary additional nozzle of the air excavator of FIG. It is an exemplary cross-sectional view of the injection hole of the additional nozzle of FIG. It is an exemplary front view of the injection hole of the additional nozzle of FIG. It is a side view which shows the additional nozzle of the air excavator which concerns on 2nd Embodiment. It is an exemplary front view of the injection hole of the additional nozzle of FIG. It is a side view which shows the additional nozzle of the air excavator which concerns on 3rd Embodiment. It is an exemplary front view of the injection hole of the additional nozzle of FIG. It is a figure explaining the experiment of the air excavator.

Hereinafter, embodiments of the air excavator according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate description will be omitted as appropriate. In addition, the drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios, angles, etc. are not limited to those described in the drawings.

As used herein, the term "injection nozzle" refers to a tubular member that allows compressed air to pass through the interior. “Compressed air” refers to compressed air, and includes, for example, air compressed by a compressor or the like for excavating earth and sand or the like. "Excavation" includes digging earth and sand, loosening hard earth and sand to soften it, and scraping mud stuck to the surface of rock or concrete skeleton. “Additional nozzle” refers to a nozzle that is additionally attached to the injection nozzle, including, for example, a tubular nozzle that is attached to the tip of an existing injection nozzle.

First, site A, which is an example of a construction site where the air excavator 1 according to the present embodiment is used, will be described. As schematically shown in FIG. 1, for example, the air excavator 1 excavates the earth and sand B of the lower part G1 of the roadside tree G for replanting the roadside tree G. The air excavator 1 is used, for example, in a narrow site A where heavy machinery cannot enter. That is, the air excavator 1 is an instrument capable of excavating earth and sand B at a narrow site A, and can effectively excavate earth and sand B even at a narrow site A.

As an example, the air excavator 1 is used together with an ejector E that sucks the excavated earth and sand B. For example, the ejector E is fixed to the ground A1 at the site A, and the first transfer pipe P1 and the second transfer pipe P2 are connected to the ejector E. The ejector E may not be fixed to the ground A1, and the operator may hold the ejector E and bring the ejector E closer to the earth and sand B to suck the earth and sand B. The first transport pipe P1 is, for example, a suction pipe for sucking the earth and sand B, and the second transport pipe P2 is a transport hose for transporting the sucked earth and sand B. As an example, the first transport pipe P1 is a rigid pipe and the second transport pipe P2 is a flexible hose.

For example, the first transport pipe P1 transports the sucked earth and sand B, and the ejector E is provided on the downstream side of the first transport pipe P1 in the transport path of the earth and sand B. The ejector E includes a steel pipe E1 for transporting the earth and sand B, and a second transport pipe P2 is provided on the downstream side of the steel pipe E1 in the transport path of the earth and sand B. For example, the earth and sand B discharged from the second transfer pipe P2 is accumulated on the downstream side of the second transfer pipe P2, and the accumulated earth and sand B is conveyed to a predetermined transfer destination.

The ejector E is divided into, for example, a steel pipe E1 to which the first transfer pipe P1 and the second transfer pipe P2 are connected, an introduction pipe E2 into which compressed air K from the compressor C is introduced, and two introduction pipes E2. A branch pipe E3 for branching is provided. Compressed air K is sent from the compressor C to the inside of the introduction pipe E2, and the compressed air K sent to the inside of the introduction pipe E2 flows into each of the two branch pipes E3. The compressed air K flowing through each branch pipe E3 merges in the steel pipe E1 and flows toward the second transport pipe P2.

The compressed air K of the compressor C is accelerated by the ejector E to generate an air flow in the transport direction of the earth and sand B. Specifically, the flow of compressed air K inside the ejector E creates a negative pressure inside the first transport pipe P1 located on the upstream side of the ejector E, and this negative pressure causes the first transport pipe P1 to have a negative pressure. Sediment B is sucked into the inside of the first transport pipe P1 from the tip. Then, the earth and sand B is conveyed inside the first transfer pipe P1, the steel pipe E1, and the second transfer pipe P2.

For example, the compressor C that supplies the compressed air K to the ejector E supplies the compressed air K to the air excavator 1, and the air excavator 1 injects the supplied compressed air K into the earth and sand B to excavate the earth and sand B. The air excavator 1 according to the present embodiment is, for example, an introduction pipe 2 extending from the compressor C and into which the compressed air K from the compressor C is introduced, and a pipe provided on the downstream side of the introduction pipe 2 in the path of the compressed air K. A portion 3 and an additional nozzle 10 attached to an end portion of the pipe portion 3 opposite to the introduction pipe 2 are provided. As an example, the introduction pipe 2 is an air hose.

FIG. 2 is a side view showing an exemplary pipe portion 3 of the air excavator 1. As an example, the pipe portion 3 is an air scoop that injects compressed air K for excavation. For example, the pipe portion 3 extends long in the longitudinal direction D1 and extends by a certain amount in the intersecting direction D2 intersecting the longitudinal direction D1. As an example, the length of the pipe portion 3 in the longitudinal direction D1 is 1000 mm or more and 1200 mm or less, and the length of the pipe portion 3 in the intersecting direction D2 is 100 mm or more and 200 mm or less. However, these values can be changed as appropriate.

The pipe portion 3 includes, for example, an air receiving portion 4 that receives compressed air K from the introduction pipe 2, an injection nozzle 5 provided at an end of the air receiving portion 4 opposite to the introduction pipe 2, an air receiving portion 4, and the air receiving portion 4. It is provided with a handle 6 for connecting the injection nozzles 5 to each other. As an example, the air receiving portion 4 is connected to the attachment portion 4b to which the introduction pipe 2 is attached, the hose 4c extending from the attachment portion 4b, and the handle 6, and opens and closes the supply path of the compressed air K of the pipe portion 3. A valve portion 4d is provided.

For example, a male screw is formed on the outer peripheral surface of the mounting portion 4b of the air receiving portion 4, and the female screw of the joint portion with the introduction pipe 2 is screwed into the male screw to connect the introduction pipe to the air receiving portion 4. 2 is connected. The hose 4c is made of, for example, a flexible material, extends from the mounting portion 4b and is bent 90 ° with respect to the mounting portion 4b. The valve portion 4d is, for example, a ball cock, and the supply path of the compressed air K is opened and closed by the rotation of the grip portion 4f of the valve portion 4d.

The handle 6 extends linearly from, for example, the valve portion 4d to the injection nozzle 5. As an example, the handle 6 has a first tubular portion 6b connected to the valve portion 4d, a second tubular portion 6c connected to the injection nozzle 5, a first tubular portion 6b, and a second tubular portion. It includes a third tubular portion 6d that connects the 6c to each other. As an example, the first tubular portion 6b and the second tubular portion 6c are both made of metal, and the third tubular portion 6d is made of a flexible material. In the conventional air excavator, a cap portion that suppresses the scattering of earth and sand B and extends outward in the radial direction of the second tubular portion 6c is provided in the vicinity of the second tubular portion 6c. However, the air excavator 1 according to the present embodiment does not have a cap portion extending outward in the radial direction.

The injection nozzle 5 is a tubular portion fixed to the tip of the second tubular portion 6c, and compressed air K to be injected to the outside is supplied to the inside of the injection nozzle 5. The pipe portion 3 including the injection nozzle 5 is, for example, an existing air scoop, and it is also possible to excavate the earth and sand B by hitting the tip portion 5b of the injection nozzle 5 against the earth and sand B.

The air excavator 1 according to the present embodiment includes, for example, an additional nozzle 10 attached to the injection nozzle 5 as shown in FIG. FIG. 3 is a side view showing an exemplary additional nozzle 10. The additional nozzle 10 is detachable from, for example, the injection nozzle 5. A female screw is formed on the inner peripheral surface of the tip portion 5b of the injection nozzle 5, and the additional nozzle 10 includes a male screw 11 screwing with the female screw on the outer periphery.

The additional nozzle 10 can be attached to and detached from the injection nozzle 5 by screwing the male screw 11 into the female screw. The additional nozzle 10 is, for example, screwed into a female screw formed on the inner peripheral surface of the injection nozzle 5 and is located at the end of the additional nozzle 10 in the longitudinal direction X1 and the male screw 11 on the opposite side of the male screw 11. A tip portion 12 located at an end portion, and a first nut portion 13, a second nut portion 14, and a third nut portion 15 located between the male screw 11 and the tip portion 12 are provided. As an example, the length L1 of the additional nozzle 10 in the longitudinal direction X1 is 80 mm or more and 120 mm or less.

The additional nozzle 10 is provided with a male screw 11 on the outer circumference. For example, the diameter of the male screw 11 is a portion other than the male screw 11 of the additional nozzle 10 (tip portion 12, first nut portion 13, second nut portion 14). And smaller than the diameter of the third nut portion 15). The first nut portion 13 is provided at the base of the male screw 11, and has an enlarged diameter from the male screw 11. As an example, a first reduced diameter portion 16 is formed between the first nut portion 13 and the second nut portion 14, and between the second nut portion 14 and the third nut portion 15. A second reduced diameter portion 17 is formed in the. For example, the male screw 11, the first nut portion 13, the first reduced diameter portion 16, the second nut portion 14, the second reduced diameter portion 17, and the third nut portion 15 are in this order in the longitudinal direction X1. Lined up along.

The tip portion 12 is provided, for example, on the side of the third nut portion 15 opposite to the second reduced diameter portion 17. The tip portion 12 may be detachable from other parts of the additional nozzle 10 by a screw. As an example, the tip portion 12 is larger than the reduced diameter portion 12b that reduces the diameter from the third nut portion 15, the fourth nut portion 12c that expands the diameter with respect to the reduced diameter portion 12b, and the fourth nut portion 12c. The additional nozzle 10 has a tip 12d located on the end side of the longitudinal direction X1. The tip 12d indicates a tubular portion whose diameter is reduced from the fourth nut portion 12c.

FIG. 4 is a diagram showing an exemplary vertical cross section of the tip 12d of the additional nozzle 10. FIG. 5 is a front view of the tip 12d as viewed along the longitudinal direction X1. As shown in FIGS. 4 and 5, the tip 12d includes, for example, a tubular portion 12f and a curved portion 12g located at the end of the tubular portion 12f in the longitudinal direction X1. As an example, the tubular portion 12f has a cylindrical shape, and compressed air K is passed through the inside of the tubular portion 12f.

For example, the curved portion 12g is a plate-shaped portion that curves outward from the end portion of the tubular portion 12f in the longitudinal direction X1 to the outside in the longitudinal direction X1. As an example, the curved portion 12g has a spherical shape protruding in the longitudinal direction X1. A plurality of injection holes 12h penetrating in the longitudinal direction X1 are formed in the curved portion 12g, and compressed air K is injected from the injection holes 12h to the outside of the additional nozzle 10. The curved portion 12g has a curved tip surface 12j facing outward in the longitudinal direction X1 and a groove portion 12k recessed from the tip surface 12j in the longitudinal direction X1.

The shape of the tip surface 12j seen from the longitudinal direction X1 is, for example, a circular shape, and the tip surface 12j protrudes in a spherical shape toward the center. The groove portion 12k extends long in, for example, a direction X2 intersecting the longitudinal direction X1, and extends from one end to the other end of the direction X2 of the tip surface 12j. As an example, the groove portion 12k extends linearly along the direction X2. The groove portion 12k has a pair of inner side surfaces 12m extending from the tip surface 12j and lined up along the direction X3, and a bottom surface 12p located on the opposite side of each inner side surface 12m from the tip surface 12j. The direction X3 indicates a direction that intersects both the longitudinal direction X1 and the direction X2, and is, for example, a direction orthogonal to each of the longitudinal direction X1 and the direction X2.

The bottom surface 12p includes, for example, a top surface 12q provided in a region including the center of the direction X2 and a pair of inclined surfaces 12r located on both ends of the direction X2 of the top surface 12q. As an example, the top surface 12q and each inclined surface 12r are flat, and each inclined surface 12r is inside the longitudinal direction X1 of the additional nozzle 10 (the groove portion 12k is deeper) from the top surface 12q toward both ends of the direction X2. It is inclined in the direction of This makes it possible to easily release the compressed air K to both ends of the direction X2.

The plurality of injection holes 12h are dispersedly arranged on the bottom surface 12p. Here, "a plurality of injection holes are dispersedly arranged" means a state in which a plurality of injection holes are evenly arranged at the tip of the additional nozzle. For example, a plurality of injection holes are arranged in the additional nozzle. A state in which they are arranged symmetrically with respect to the center of the tip, a state in which a plurality of injection holes are arranged in a grid pattern, or a state in which a plurality of injection holes are arranged in a concentric manner. The state of being is included.

In the present embodiment, the plurality of injection holes 12h are arranged in a staggered manner. For example, the bottom surface 12p is provided with a plurality of sets M of a plurality of injection holes 12h arranged along the direction X2, and the number of sets M is 3 as an example. The three sets M are arranged along the direction X3, and the set M located at the center of the direction X3 among the three sets M includes seven injection holes 12h. Further, among the three sets M, the sets M located on both sides of the direction X3 include six injection holes 12h.

One of the injection holes 12h of the set M located at the center of the direction X3 is provided at the center of the tip surface 12j, for example. As an example, one injection hole 12h is formed on the top surface 12q, and all the injection holes 12h other than the one injection hole 12h are formed on the inclined surface 12r. For example, the diameter L2 of the tip surface 12j when viewed from the longitudinal direction X1 is 10 mm or more and 30 mm or less, the width L3 of the direction X3 of the groove portion 12k is 5 mm or more and 10 mm or less, and the diameter L4 of each injection hole 12h is It is 0.5 mm or more and 2.0 mm or less.

Although the tip portion 12 of the additional nozzle 10 has been described in detail above, the shape, size, number, material, and arrangement mode of the tip portion 12 are not limited to the above-mentioned examples and can be appropriately changed. For example, the shape, size, number, and arrangement of the injection holes 12h are not limited to the example shown in FIG. 5, and can be appropriately changed. Hereinafter, the operation and effect of the air excavator 1 provided with the additional nozzle 10 according to the present embodiment will be described in detail.

As shown in FIGS. 2 to 5, the air excavator 1 includes a tubular injection nozzle 5, and an additional nozzle 10 is further attached to the tip portion 5b of the injection nozzle 5. The additional nozzle 10 has a plurality of injection holes 12h for injecting compressed air K to the outside. Therefore, the compressed air K passing through the inside of the injection nozzle 5 is dispersed in the plurality of injection holes 12h, so that it is possible to prevent the compressed air from concentrating in one injection hole.

Therefore, since the compressed air K dispersed from each of the plurality of injection holes 12h is injected, it is possible to reduce the scattering of earth and sand B and the like accompanying the injection of the compressed air K. As a result, it is possible to suppress the scattering of the earth and sand B and the like over a wide area, so that it is possible to eliminate the situation where the earth and sand B and the like obstruct the view of the worker and the worker sucks the earth and sand B and the like. Become. Further, since it is possible to suppress the scattering of the earth and sand B and the like over a wide range, it is possible to suppress the scattering of the earth and sand and the like to the outside of the site A, and it is possible to suppress the possibility of damaging the environment around the site A. When the compressed air K is dispersed and injected from each injection hole 12h, the noise associated with the injection can be reduced.

Further, since the scattering of the earth and sand B and the like is suppressed over a wide range, it is possible to eliminate the need for the shade portion that suppresses the scattering of the earth and sand B and the like. Therefore, since the cap portion does not get in the way, it is possible to avoid a situation in which the cap portion obstructs the view and interferes with the work, and the work can be performed while visually recognizing the compressed air K from the injection hole 12h. As a result, the workability and safety of the excavation work can be improved.

Further, since the compressed air K passing through the inside of the injection nozzle 5 is dispersed in the plurality of injection holes 12h, the pressure of the compressed air K to be injected can be reduced, so that the air excavation accompanying the injection of the compressed air K can be performed. It is possible to suppress the rampage of the tool 1 (pipe portion 3). Therefore, the length of the pipe portion 3 can be shortened, the weight of the pipe portion 3 can be reduced, and the handling of the air excavator 1 can be facilitated.

Further, the additional nozzle 10 is removable from the injection nozzle 5. Therefore, when the additional nozzle 10 is clogged, the additional nozzle 10 can be removed and the additional nozzle 10 can be cleaned. Further, since the additional nozzle 10 can be easily replaced, it is possible to easily replace the additional nozzle 10 with another type when different types of additional nozzles 10 are prepared.

Further, a female screw is formed on the inner peripheral surface of the tip portion 5b of the injection nozzle 5, the additional nozzle 10 is provided with a male screw 11 screwing with the female screw on the outer circumference, and the additional nozzle 10 is a male screw. 11 is screwed into the female screw so that it can be attached to and detached from the injection nozzle 5. Therefore, since the male screw 11 on the outer peripheral surface of the additional nozzle 10 is screwed into the female screw on the inner peripheral surface of the injection nozzle 5, it is possible to suppress the enlargement of the diameters of the injection nozzle 5 and the additional nozzle 10. Further, since the male screw 11 of the additional nozzle 10 can be screwed into the female screw of the injection nozzle 5 to attach the additional nozzle 10, the additional nozzle 10 can be easily attached to and detached from the injection nozzle 5. ..

Further, the additional nozzle 10 may have a groove portion 12k recessed from the tip surface 12j of the additional nozzle 10 located on the opposite side of the injection nozzle 5. In this case, when the tip surface 12j of the additional nozzle 10 is pressed against the earth and sand B or the like, a gap is formed between the groove portion 12k and the earth and sand B or the like. Therefore, since the compressed air K injected from the additional nozzle 10 to the earth and sand B or the like is dispersed and discharged through the voids, the pressure of the compressed air K injected from the injection hole 12h can be dispersed. Therefore, it is possible to more reliably suppress the scattering of earth and sand B and the like due to the injection of the compressed air K.

Further, the additional nozzle 10 has a plurality of injection holes 12h, and the plurality of injection holes 12h may be opened to the bottom surface 12p of the groove portion 12k. In this case, when the tip surface 12j of the additional nozzle 10 is pressed against the earth and sand B or the like, a gap is formed between each of the plurality of injection holes 12h opened in the bottom surface 12p of the groove 12k and the earth and sand B or the like. .. Therefore, since the compressed air K injected from the additional nozzle 10 to the earth and sand B and the like is injected into the earth and sand B and the like through the voids, the pressure of the compressed air K injected into the earth and sand B and the like can be suppressed. Therefore, the scattering of earth and sand B can be suppressed more reliably.

Further, the groove portion 12k extends from one end to the other end of the tip surface 12j, and the plurality of injection holes 12h may be dispersedly arranged on the bottom surface 12p of the groove portion 12k. In this case, since the groove portion 12k extends from one end to the other end of the tip surface 12j, the compressed air K from the injection hole 12h is released to one end and the other end of the tip surface 12j through the groove portion 12k to inject. The concentration of compressed air K to be produced can be suppressed. Further, since the plurality of injection holes 12h are dispersedly arranged on the bottom surface 12p of the groove portion 12k, the compressed air K can be dispersed and injected from each of the plurality of injection holes 12h. Therefore, it is possible to more reliably suppress the scattering of earth and sand B and the like due to the injection of the compressed air K.

Further, as shown in FIG. 1, the air excavator 1 provided with the additional nozzle 10 is used together with the ejector E that sucks and conveys the earth and sand B. Therefore, the air excavator 1 excavates the earth and sand B while suppressing the scattering of the earth and sand B and the like over a wide area, and the excavated earth and sand B is sucked and conveyed by the ejector E. Therefore, since the earth and sand B efficiently excavated by the air excavator 1 can be quickly sucked and transported by the ejector E, the excavation work of the earth and sand B can be smoothly performed.

(Second Embodiment)
Next, the additional nozzle 20 according to the second embodiment will be described with reference to FIGS. 6 and 7. As shown in FIGS. 6 and 7, the additional nozzle 20 is screwed into, for example, a female screw formed on the inner peripheral surface of the injection nozzle 5 and is a male located at the end of the additional nozzle 20 in the longitudinal direction X1. It includes a screw 21, a tip portion 22 located at the opposite end of the male screw 21, and a diameter-expanded portion 23 located between the male screw 21 and the tip portion 22. As an example, the length L5 of the additional nozzle 20 in the longitudinal direction X1 is 20 mm or more and 40 mm or less. In the following description, in order to avoid duplication, the description that overlaps with the first embodiment will be omitted as appropriate.

The diameter-expanded portion 23 is provided at the base of the male screw 21, and the diameter is expanded from the male screw 21. The shape of the enlarged diameter portion 23 seen from the longitudinal direction X1 is, for example, a hexagonal shape. The tip portion 22 is provided on the opposite side of the enlarged diameter portion 23 from the male screw 21. The tip portion 22 may be detachable from other parts of the additional nozzle 20 by a screw. As an example, the tip portion 22 has a tubular portion 22b whose diameter is reduced from the diameter-expanded portion 23, and a tapered portion 22c located on the opposite side of the tubular portion 22b from the diameter-expanded portion 23.

The tubular portion 22b has, for example, a cylindrical shape. The tapered portion 22c has a tapered surface 22d whose diameter is gradually reduced from the end of the tubular portion 22b in the longitudinal direction X1, and a tip surface 22f located at one end of the additional nozzle 20 in the longitudinal direction X1. The shape of the tip surface 22f seen from the longitudinal direction X1 is, for example, an annular shape, and a circular recess 22g recessed in the longitudinal direction X1 is formed inside the annular tip surface 22f.

A plurality of groove portions 22h extending radially from the recess 22g are formed on the radial outer side of the recess 22g, and the tip surface 22f is divided into a plurality of portions by the groove portions 22h. Injection holes 22j for ejecting compressed air K to the outside of the additional nozzle 20 are formed on each of the divided tip surfaces 22f. For example, the groove portions 22h and the injection holes 22j are alternately arranged along the circumferential direction of the tip surface 22f.

As an example, the groove portions 22h and the injection holes 22j are both arranged at equal intervals along the circumferential direction of the tip surface 22f. For example, the number of groove portions 22h and the number of injection holes 22j are 8, and both the groove portions 22h and the injection holes 22j are arranged with a phase angle of 45 °. Further, each groove portion 22h extends radially outward from the recess 22g and extends toward the center side of the additional nozzle 20 in the longitudinal direction X1, and extends to the tapered surface 22d and the tubular portion 22b. As an example, the diameter L6 of the tip surface 22f is 10 mm or more and 20 mm or less, and the diameter L7 of each injection hole 22j is 0.5 mm or more and 2.0 mm or less.

As described above, the additional nozzle 20 according to the second embodiment has a plurality of injection holes 22j for injecting compressed air K to the outside. Therefore, since the compressed air K passing through the inside of the injection nozzle 5 is dispersed in the plurality of injection holes 22j, the scattering of the earth and sand B and the like can be suppressed, so that the same effect as that of the first embodiment can be obtained. Further, in the second embodiment, a plurality of groove portions 22h recessed from the tip surface 22f are formed radially, and each groove portion 22h extends from the tip surface 22f along the longitudinal direction X1. Therefore, since the compressed air K can be efficiently dispersed in each groove portion 22h, the scattering of earth and sand B and the like can be suppressed more reliably.

Further, the additional nozzle 20 has a plurality of injection holes 22j, and the plurality of injection holes 22j are arranged in a circular shape on the tip surface 22f of the additional nozzle 20 located on the opposite side of the injection nozzle 5. Therefore, since the compressed air K is injected from each of the plurality of injection holes 22j arranged in a circular shape, the dispersed compressed air K can be injected from each injection hole 22j. As a result, the scattering of earth and sand B and the like can be suppressed more reliably.

(Third Embodiment)
Subsequently, the additional nozzle 30 according to the third embodiment will be described with reference to FIGS. 8 and 9. As shown in FIGS. 8 and 9, the additional nozzle 30 is screwed into, for example, a female screw formed on the inner peripheral surface of the injection nozzle 5 and is a male located at the end of the additional nozzle 30 in the longitudinal direction X1. The screw 31 and the tip portion 32 located at the opposite end of the male screw 31 and the first nut portion 13, the diameter-expanded portion 33 and the third nut portion located between the male screw 31 and the tip portion 32. It is provided with 15. As an example, the length L8 of the additional nozzle 30 in the longitudinal direction X1 is 80 mm or more and 120 mm or less.

As an example, the diameter-expanded portion 33 includes a first tubular portion 33b located on the male screw 31 side, a second tubular portion 33c located on the tip portion 32 side, and a first tubular portion 33b to the first. It has a tapered portion 33d extending to the tubular portion 33c of 2. The diameter of the second tubular portion 33c is larger than the diameter of the first tubular portion 33b, and the diameter of the tapered portion 33d gradually increases from the first tubular portion 33b toward the second tubular portion 33c. It has become.

The tip portion 32 is provided, for example, on the side of the third nut portion 15 opposite to the second reduced diameter portion 17. The tip portion 32 may be made removable by a screw with respect to another portion of the additional nozzle 30. As an example, the tip portion 32 has a fourth nut portion 12c and a tip portion 32d located on the end side of the additional nozzle 30 in the longitudinal direction X1 with respect to the fourth nut portion 12c. The tip 32d has a small diameter with respect to the fourth nut portion 12c and indicates a portion protruding in the longitudinal direction X1.

The tip 32d has, for example, a tip surface 32g that curves and projects in the longitudinal direction X1. As an example, the tip surface 32g projects hemispherically. An injection hole 32h penetrating in the longitudinal direction X1 is formed on the tip surface 32g, and compressed air K is injected from the injection hole 32h to the outside of the additional nozzle 30. The shape of the tip surface 32g seen from the longitudinal direction X1 is, for example, a circular shape, and the tip surface 32g projects spherically toward the center.

The injection hole 32h has a flat shape extending in the direction X2 on the tip surface 32g. For example, the injection hole 32h extends linearly in the direction X2 at the tip surface 32g, and may extend from one end to the other end of the direction X2 of the tip surface 32g. In other words, the injection hole 32h has a rectangular shape having a long side extending in the direction X2 and a short side extending in the direction X3. As an example, the length L9 of the direction X2 of the injection hole 32h is 10 mm or more and 20 mm or less, and the width L10 of the direction X3 of the injection hole 32h is 0.5 mm or more and 2.0 mm or less.

As described above, the additional nozzle 30 according to the third embodiment has a flat injection hole 32h that injects compressed air K to the outside and extends long in the direction X2. Therefore, the compressed air K passing through the inside of the injection nozzle 5 is injected to the outside from the flat injection hole 32h extending in the direction X2, and the cross-sectional area of the injection hole 32h through which the compressed air K passes can be widened. It is possible to suppress the concentration of compressed air in the holes.

Therefore, since the compressed air K is injected from the flat injection hole 32h extending in the direction X2, it is possible to suppress the scattering of earth and sand and the like accompanying the injection of the compressed air K. As a result, similar to the above-mentioned air excavator 1 and the like, it is possible to suppress the scattering of the earth and sand B and the like over a wide area, and the earth and sand B and the like obstruct the view of the worker and the worker sucks the earth and sand B and the like. This can be suppressed, and the possibility of damaging the environment around the site A can be suppressed.

Further, since it is possible to suppress the scattering of earth and sand B and the like over a wide range, the above-mentioned shade portion can be eliminated. Therefore, it is possible to prevent the cap portion from obstructing the view of the worker, and the worker can perform the work while visually recognizing the compressed air K from the injection hole 32h, so that the workability and safety of the excavation work can be performed. Can be enhanced. Therefore, the same effect as that of each of the above-described embodiments can be obtained.

The embodiment of the air excavator according to the present invention has been described above. However, the air excavator according to the present invention is not limited to each of the above-described embodiments, and may be modified or applied to other objects without changing the gist described in each claim. Good. That is, the configuration of each part of the air excavator can be variously modified without changing the gist of each claim.

For example, in the above-described embodiment, the additional nozzle 10 having the circular injection hole 12h and the additional nozzle 30 having the flat injection hole 32h have been described. However, the shape of the injection hole of the additional nozzle may be, for example, an oval shape including an ellipse, a polygonal shape, a corrugated shape, or an X-shape, and can be appropriately changed. Further, the size, number, and arrangement of the injection holes are not limited to the above-described embodiments and can be appropriately changed.

For example, in the above-described embodiment, the additional nozzle 10 that can be attached to and detached from the injection nozzle 5 by screwing the male screw 11 to the female screw has been described. However, the means for attaching / detaching the additional nozzle to the injection nozzle may be other than the male screw and the female screw. For example, one of the injection nozzle and the additional nozzle is provided with an engaging portion such as a latch, and the other is provided with an engaged portion. When the engaging portion engages with the engaged portion, the additional nozzle becomes an injection nozzle. It may be removable. Further, the additional nozzle may not be removable to the injection nozzle.

Further, in the above-described embodiment, an example in which the injection nozzle 5 is provided in the pipe portion 3 and the pipe portion 3 is an existing air scoop has been described. However, the pipe portion is not limited to the existing air scoop, and the shape, size, material, number, and arrangement mode of each portion of the pipe portion can be appropriately changed. Further, the injection nozzle may be connected to something other than the pipe portion 3, and the object to which the injection nozzle is connected is not particularly limited.

Further, in the above-described embodiment, the air excavator 1 for excavating the earth and sand B of the lower portion G1 of the roadside tree G has been described. However, the air excavator according to the present invention may excavate a portion other than the earth and sand under the roadside tree, and various types can be excavated by compressed air. For example, it may be an air excavator that loosens and softens hard ground, or it may be an air excavator that cleans mud or the like stuck to the surface of rock or concrete skeleton. The type of site where the air excavator is used can be changed as appropriate.

(Example)
Subsequently, examples of the present invention will be described. The present invention is not limited to the following examples. In the experiment of this example, the additional nozzle according to the first embodiment of the porous fan shape in which the plurality of injection holes 12h shown in FIG. 5 are arranged in a staggered manner, and the plurality of circular injection holes 22j shown in FIG. 7 are formed. Using each of the additional nozzle according to the circular type Example 2, the additional nozzle according to the third embodiment in which the flat injection hole 32h shown in FIG. 9 is formed, and the comparative example having no additional nozzle. Sediment B was excavated. In the comparative example, the compressed air K is injected from the injection nozzle 5 having a circular injection hole formed in the center, and no additional nozzle is provided.

As shown in FIG. 10, the additional nozzle according to the first embodiment of the porous fan shape, the additional nozzle according to the second embodiment of the circular injection hole, the additional nozzle according to the third embodiment of the flat injection hole, and the comparative example. Compressed air K was injected from each of the injection nozzles 5 according to the above, and the volume was measured, and the maximum scattering height Y1 of the earth and sand B, the average excavation diameter Y2, and the excavation depth Y3 were measured. The volume was measured at 0 m, 1 m, 3 m and 5 m from the excavation point. The results of the measured volume are shown in Table 1 below.

As shown in Table 1, the volume of excavation at a position 0 m from the excavation point was reduced by 22.4% (from 107 dB to 83 dB) when the additional nozzle of the porous fan shape of Example 1 was attached. ). Further, the volume of excavation at a position 0 m from the excavation point was reduced by 19.6% (reduced from 107 dB to 86 dB) as compared with the comparative example when the additional nozzle of the flat injection hole of Example 3 was attached. Further, the volume of excavation at a position 3 m from the excavation point was reduced by 14.3% (84 dB was reduced to 72 dB) as compared with the comparative example when the additional nozzle of the circular injection hole of Example 2 was attached. As described above, it was found that when any of the additional nozzles of Examples 1 to 3 was attached, the volume of excavation could be reduced more reliably than in the comparative example.

Table 2 below shows the measurement results of the maximum scattering height Y1, the average diameter Y2, and the depth Y3 when the earth and sand B, which is a sandy ground having a water content of 6.4%, is continuously excavated for 5 minutes.

From Table 2 above, it was found that in the case of the comparative example without the additional nozzle, the maximum scattering height Y1 of the earth and sand B was 1.3 m or more, and the excavated earth and sand B soared to a height reaching the upper body of the worker. .. On the other hand, when the additional nozzles of Examples 1 to 3 are attached, the maximum scattering height Y1 of the earth and sand B can be suppressed to 1.0 m or less, and further, the additional nozzle having the perforated fan-shaped injection hole of Example 1 can be provided. It was found that the maximum scattering height Y1 of the earth and sand B could be suppressed to 0.8 m or less when attached. On the other hand, the average diameter Y2 of excavation is 0.27 m to 0.3 m in both Examples 1 to 3 and Comparative Example, and the depth Y3 of excavation is 0.27 m to 0 in both Examples 1 to 3 and Comparative Example. It was 47 m, and it was found that there was no big difference. As described above, it was found that when the additional nozzles of Examples 1 to 3 were attached, the maximum scattering height and noise of the earth and sand B could be effectively suppressed as compared with the comparative example while maintaining the desired excavation force. It was.

1 ... Air excavator, 2 ... Introduction pipe, 3 ... Pipe part, 4 ... Air receiving part, 4b ... Mounting part, 4c ... Hose, 4d ... Valve part, 4f ... Gripping part, 5 ... Injection nozzle, 5b ... Tip part 10, 20, 30 ... Additional nozzles 11, 21, 31 ... Male screw, 12, 22, 32 ... Tip, 12b ... Reduced diameter, 12c ... Nut, 12d, 32d ... Tip, 12f ... Cylindrical , 12g ... curved part, 12h ... injection hole, 12j ... tip surface, 12k ... groove part, 12m ... inner surface, 12p ... bottom surface, 12q ... top surface, 12r ... inclined surface, 13 ... first nut part, 14 ... first 2 nut part, 15 ... 3rd nut part, 16 ... reduced diameter part, 17 ... reduced diameter part, 22b ... tubular part, 22c ... tapered part, 22d ... tapered surface, 22f ... tip surface, 22g ... concave part, 22h ... Groove, 22j ... Injection hole, 23 ... Diameter expansion, 32g ... Tip surface, 32h ... Injection hole, 33 ... Diameter expansion, 33d ... Tapered, A ... Site, A1 ... Ground, B ... Sediment, C ... Compressor, D1 ... longitudinal direction, D2 ... crossing direction, E ... ejector, E1 ... steel pipe, E2 ... introduction pipe, E3 ... branch pipe, G ... street tree, K ... compressed air, L1 ... length, L2 ... diameter, L3 ... width, L4, L6, L7 ... diameter, L10 ... width, M ... set, P1 ... first transport pipe, P2 ... second transport pipe, X1 ... longitudinal direction, X2, X3 ... direction, Y1 ... maximum scattering High, Y2 ... average diameter, Y3 ... depth.

Claims (8)

An air excavator that allows compressed air to pass through the inside of a tubular injection nozzle and injects the compressed air for excavation.
With an additional nozzle attached to the tip of the injection nozzle,
The additional nozzle has a plurality of injection holes for injecting the compressed air to the outside.
Air excavator. An air excavator that allows compressed air to pass through the inside of a tubular injection nozzle and injects the compressed air for excavation.
With an additional nozzle attached to the tip of the injection nozzle,
The additional nozzle injects the compressed air to the outside and has a flat injection hole extending in one direction.
Air excavator. The additional nozzle is removable from the injection nozzle.
The air excavator according to claim 1 or 2. A female screw is formed on the inner peripheral surface of the tip of the injection nozzle.
The additional nozzle is provided with a male screw screwing with the female screw on the outer circumference.
The additional nozzle is detachable from the injection nozzle by screwing the male screw into the female screw.
The air excavator according to any one of claims 1 to 3. The additional nozzle has a groove recessed from the tip surface of the additional nozzle located on the opposite side of the injection nozzle.
The air excavator according to any one of claims 1 to 4. The additional nozzle has a plurality of the injection holes.
The plurality of injection holes are open to the bottom surface of the groove.
The air excavator according to claim 5. The groove extends from one end to the other end of the tip surface.
The plurality of injection holes are dispersedly arranged on the bottom surface of the groove.
The air excavator according to claim 5 or 6. The additional nozzle has a plurality of the injection holes.
The plurality of injection holes are arranged in a circular shape on the tip surface of the additional nozzle located on the opposite side of the injection nozzle.
The air excavator according to any one of claims 1 to 7.

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