JP7148959B2 - Injection nozzle device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite jet nozzle device for grinding an object to be ground, such as concrete, by injecting a composite jet composed of a high-pressure liquid and a powdery abrasive.

Generally, in construction such as highway widening, seismic reinforcement, or wall reinforcement of buildings, the water jet construction method uses ultra-high pressure water jets ejected from ultra-high pressure nozzles to chip concrete without damaging reinforcing bars. is used. In this water jet method, finely squeezed ultra-high-pressure water is jetted from an ultra-high-pressure nozzle to an object (Patent Document 1), and abrasive grains are mixed in this jet flow to increase the grinding efficiency. (Patent Document 2).

JP-A-6-178953 JP-A-5-345277

However, the chipping and peeling work of concrete, etc. by the water jet method using the ultra-high pressure nozzle of Patent Document 1 is a water jet of only water, and the nozzle diameter is about 1 mm, so the grinding area is small and the work efficiency is high. There is a limit to the improvement of grinding efficiency even if the water pressure is increased.

In addition, the slurry nozzle of Patent Document 2 is provided with a mixing chamber for mixing the water jet and the abrasive grains inside the nozzle, and the slurry mixed here is supplied to a nozzle member with a small diameter and a fixed length connected to the mixing chamber. However, the nozzle member has a small diameter and is easily clogged with abrasive grains.

In view of this point, the present invention aims to improve the grinding efficiency by ejecting a composite jet in which a line-shaped high-pressure liquid is surrounded by a swirling flow of pressurized gas containing an abrasive material, thereby improving the grinding efficiency and removing powder abrasive grains from the nozzle. An object of the present invention is to provide an injection nozzle device that does not cause clogging due to contamination.

The injection nozzle device of the present invention comprises a main body having therein a truncated conical composite swirl flow forming space for forming a truncated conical composite swirl flow, and a pressurized gas spirally along the inner wall of the main body. a pressurized gas guide member for guiding; a pressurized gas supply pipe for sending the pressurized gas into the space along the guide member; a supply pipe and a liquid pumping nozzle mounted on the body for supplying a jet of high-pressure liquid onto the axis of the space; Composite jet surrounded by swirling flow of pressurized gas is made to collide with the object to be ground from the tip nozzle of the main body.

The composite jet consists of a fine-diameter high-pressure liquid jet and a pressurized gas mixture swirl jet containing an abrasive material located radially outside the jet and swirling around it.

The main body can also be made of resin.

The pressure gas guide member is a spiral groove, plate-like fin or protrusion formed on the inner wall of the main body, and the spiral is preferably formed so that the pitch gradually decreases toward the tip of the main body. .

In addition, it is preferable that the tip of the pressure gas supply pipe opens in the arrangement direction of the pressure gas guide member, and the tip of the grinding member supply pipe opens in the flow direction of the swirling flow of the pressure gas.

It is preferable that the ratio of the diameter of the large-diameter end of the space, the diameter of the small-diameter end forming the injection port of the composite jet, and the length of the space along the axial center is 2:1:3.

In the present invention, pressurized air as pressure gas is turned into a swirling flow in the nozzle device main body, and the abrasive is mixed with this. Since the composite jet is ejected from the tip nozzle at the tip of the main body so as to surround the object, the diameter of the composite jet jetted from the tip nozzle is larger than that of the conventional one, and as a result, the grinding area is remarkably large. and the grinding efficiency increases. In addition, the abrasive is mixed in the swirl flow of the surrounding air without mixing the abrasive into the fine-diameter jet of water (does not create slurry). does not occur.

Further, if the pitch of the helical guide member for guiding the pressurized gas in the main body axial direction is formed so as to gradually decrease as it approaches the tip of the injection nozzle main body, the speed of the mixed swirl flow will gradually increase, and the swirl will increase. The grinding effect of the swirling flow containing the abrasive grains increases while the fine-diameter jet of water is held in the center.

1 is a configuration diagram of a road chipping device in which an injection nozzle device of the present invention is applied to road grinding work; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a gun-type wall grinding device in which an injection nozzle device of the present invention is applied to grinding work of a building; 1 is a perspective view of an injection nozzle device of the present invention; FIG. 1 is a longitudinal sectional view of an injection nozzle device of the present invention; FIG. FIG. 3 is an explanatory view showing a jet state as viewed from the top of the injection nozzle device of the present invention; FIG. 5 is an explanatory view showing a composite jet state at the tip of the main body of the injection nozzle device of the present invention; FIG. 5 is a partial perspective view showing another embodiment of the pressure gas guide member formed on the inner wall of the injection nozzle device of the present invention; FIG. 5 is a partial perspective view showing still another embodiment of a pressure gas guide member formed on the inner wall of the injection nozzle device of the present invention;

Preferred embodiments of the present invention are described below with reference to the drawings.

1 and 2, a road chipping device M ₁ for chipping or peeling a concrete surface 2 equipped with an injection nozzle device 1 of the present invention is provided with a movable pedestal 3. is supported by wheels 4, 4, and the injection nozzle device 1 moves horizontally back and forth and left and right along the support frame 5 of the base 3, and the abrasive is wrapped around the linear water jet, which is a high-pressure liquid. Grinding of the concrete surface is performed by a composite jet with a circular cross section.

A water supply tank 6 for supplying high-pressure water to the injection nozzle device 1; An air tank 8 for storing the air of the pressurized gas, a compressor 10 for pressurizing the air to the injection nozzle device 1 via a flow control valve 9, and garnet or silica sand used for sandpaper or the like. and a compressor 12 for supplying a predetermined amount of the abrasive to the injection nozzle device 1. These mechanical elements are electrically connected to each other. A controller C is provided for controlling.

FIG. ₂ shows a grinding device _M2 for grinding a wall surface 20 of a building. A nozzle gun type is adopted as the jet grinding device M2. , to this injection nozzle device ₁ are connected respective mechanical elements of the road chipping device M1.

The structure of the injection nozzle device 1 of the present invention will be described below.

3 and 4, the nozzle device 1 of the present invention comprises an inverted truncated cone-shaped casing body 30, the upper surface of which is closed by a circular closing plate 31, and the lower surface of which is provided with a composite jet. A tip nozzle 32 for jetting is connected. A liquid pressure feed nozzle 33 for linearly injecting water as a high-pressure liquid is connected to the center of the closing plate 31 . The casing main body 30 and the closing plate 31 are preferably made of resin such as acryl which can be easily molded, but they may be made of metal. Also, alcohol or the like can be used as the pressurized liquid in the case of the cleaning operation of the metal surface.

The liquid pressure feed nozzle 33 has a nozzle diameter of about 1 mm, and as a result, the water jet 34 with a diameter of about 1 mm descends from the axial center position of the injection nozzle device 1 to become a composite jet, and collides with the object via the tip nozzle 33. . Water from the water supply tank 6 is pressurized to a pressure of about 1800 to 2500 kg/cm ² by the super-high pressure pump 7 and supplied to the liquid pressure feed nozzle 33 . The high-pressure water jet 34 generates a negative pressure in the inverted truncated cone-shaped compound swirling flow forming chamber 35 in the main body 30 of the injection nozzle device 1 due to its ejector effect, which causes strong suction toward the downstream side. A force is generated and the negative pressure is regulated by a negative pressure regulating valve 36 mounted on the body 30 . Preferably, the diameter D1 of the upper surface of the body 30 is _about 30 mm, the diameter D2 of the _lower surface is about 15 mm, and the length L in the axial direction is about 90 mm. That is, it is preferable to set D ₁ :D ₂ :L=2:1:3.

Air from the air tank 8 is pressure-fed (7 kg/
cm ³ ), an air supply pipe 37 (end opening 37a) to which air (other gases such as nitrogen may be used) is supplied as a pressure gas for grinding, and an abrasive supply pipe 38 for supplying the powder abrasive. (tip opening 38a) is attached. As shown in FIG. 4, a spiral guide groove 39 is formed on the inner wall of the main body 30, and the pitch of the guide groove 39 becomes narrower as it descends (pitch at the upper part of the main body:pitch at the lower part of the main body=2:1). The pressurized air spirally descends along the guide groove 39 to generate a high-speed rotating swirl flow, and the abrasive is sucked into and mixed with the high-speed rotating airflow from the abrasive supply pipe 38 . The tip portion of the air supply pipe 37 is open along the guide groove 39 so as to generate an air flow along the guide groove 39, and the tip portion of the abrasive supply pipe 38 also moves the abrasive along the swirling air flow. is open so that the

The abrasive is supplied at a rate of about 3 kg per minute, and as shown in FIGS. The water jet 34 injected at the axial position is covered to generate a composite jet 42 centering on the water jet, and a composite swirling flow 41 whose velocity gradually increases around the water jet 34 at the center of the composite jet. cover to hold the water jet in a centered position. By setting the diameter of the composite jet 42 to about 15 mm, the diameter of the tip nozzle 32 can be set to the same diameter, and the diameter of the conventional water jet is about 1 mm. It has been confirmed that the work efficiency of chipping is approximately tripled.

Since the tip nozzle 32 on the lower surface of the main body has a large diameter of about 15 mm, clogging of the mixed swirling flow containing abrasive grains does not occur.

The inner wall of the main body 30 is formed with a spiral guide groove 39 for generating a high-speed swirling flow 41. Instead of this, plate-like spiral fins 50 are planted on the inner wall as shown in FIG. Alternatively, as shown in FIG. 8, a helical projection 51 may be formed on the inner wall.

The injection nozzle device of the present invention can be used for repairing roads, repairing building walls or cleaning metal surfaces.

REFERENCE SIGNS LIST 1 injection nozzle device 3 mount 20 wall surface 21 nozzle gun 30 casing main body 32 tip nozzle 33 liquid pumping nozzle 34 water jet 35 complex swirling flow forming chamber 37 air supply pipe 38 abrasive supply pipe 39 ... Guide groove 40 ... Air swirl flow 41 ... Mixed swirl flow 42 ... Composite jet flow

Claims (4)

a main body having a truncated cone-shaped composite swirl flow forming space for forming a truncated cone-shaped swirl flow therein;
a pressure gas guide member for guiding the pressure gas spirally along the inner wall of the body;
a pressurized gas supply pipe for sending the pressurized gas into the space along a guide member;
an abrasive supply pipe for supplying an abrasive to the pressurized gas so as to mix the abrasive within the body;
a liquid pumping nozzle mounted on the body for supplying a jet of high-pressure liquid onto the axis of the space;
The pressure gas guide member is a helical groove, plate-like fin or protrusion formed on the inner wall of the body, and the ratio of the helical pitch at the upper part of the body to the helical pitch at the lower part of the body is 2. is to one,
The ratio of the diameter of the large-diameter end of the space to the diameter of the tip small-diameter end forming the injection port of the composite jet and the length along the axis of the space is 2:1:3,
An injection nozzle device in which a compound jet, in which the fine-diameter jet of high-pressure liquid is surrounded by a swirling flow of pressurized gas containing an abrasive material, collides with an object to be ground from a tip nozzle of a main body. 2. The injection nozzle device according to claim 1, wherein said composite jet comprises a fine-diameter high-pressure liquid jet and a pressurized gas mixture swirl jet containing an abrasive located radially outside and swirling around it. 2. The injection nozzle device according to claim 1, wherein said main body is made of resin. the tip of the pressure gas supply pipe is open in the arrangement direction of the pressure gas guide member,
2. The injection nozzle device according to claim 1 , wherein the tip of said abrasive supply pipe is open in the flow direction of the swirling flow of the pressurized gas .

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