JPH0341819Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> The present invention relates to an improvement of a spray nozzle for pressurized injection material such as concrete.

<<Conventional technology and its problems>> The spraying method is commonly used as a construction method for concrete (including mortar, hereinafter the same). This spraying method can be roughly divided into wet and dry methods, but in both cases, the kneaded materials are fed under pressure through a conduit such as a hose, and compressed air is used as a medium from a spray nozzle at the end of the conduit to the target surface. It is something that is sprayed.

In this spraying method, it is desirable to suppress the generation of dust as much as possible from the viewpoint of preserving the working environment, saving resources, and improving the quality and quality of the lining layer, and also to reduce the sagging of the material. Although various attempts have been made regarding spraying systems and formulations, the reality is that no satisfactory results have been obtained.

In the past, no effective consideration has been given to the spray nozzle, which is a place where dust and material drips, and it is simply a straight tube, a tapered tube, or a stepped taper tube, including the discharge part at the tip of the tube. It simply had a circular cross-section as a whole.

In this structure, because the cross section of the passage is circular, the centrifugal force caused by the high-speed swirling flow continues all the way to the discharge port.
Since the material is injected in an enhanced state, the material,
In particular, it is unavoidable that fine powder spreads over a wide area.

In addition, during pressure feeding, the paste tends to separate from the main flow and form a bottom flow due to the difference in specific gravity and frictional resistance with the inner wall of the pipe, and the above cross section has a structure that promotes the bottom flow, so the paste flows directly from the discharge port. tends to flow down in large quantities as sag.

As mentioned above, this invention was devised through research to solve the problems of conventional spray nozzles.
The purpose is to provide a spray nozzle for pressure-fed materials such as concrete that can suppress the generation of dust with a simple structure and prevent the paste from sagging due to pipe bottom flow. be.

Another object of the present invention is to provide a spray nozzle which can prevent paste from adhering to the tip of the nozzle and blockage caused by this, and which can facilitate cleaning at the end of spraying. .

<<Means for Solving the Problems>> In order to achieve the above object, the present invention provides a pipe that is connected to the tip of a pipe with a circular cross section that pumps a mixed fluid pumping injection material such as concrete and mortar,
A cylindrical body that sprays the projectile onto the construction surface,
A predetermined range of the tip of the cylindrical body is formed to have a rectangular cross section with a smaller cross-sectional area than the pipe.

<<Example>> Hereinafter, an example of the present invention will be described based on the accompanying drawings.

1 to 4 show an embodiment of the spray nozzle for pressurized injection materials such as concrete and mortar according to the present invention. 1 is the spray nozzle according to the present invention, and the rear end is connected to a hose or the like by a joint 3. It is connected to the material pressure-feeding conduit 2.

The spray nozzle 1 has a cylindrical shape as a whole, which is similar to conventional nozzles of this type, but in the present invention, the required length l ₁ of the tube tip is changed to a rectangular cross section 5.
In addition, the section ₁₂ from the end of the rectangular cross section 5 is configured as a section 6 that gradually deforms from a circular cross section to a rectangular cross section, and the section _l3 behind this section is configured as a circular cross section 7.

An example of the cross-sectional shape of the gradual deformation section 6 from the circular cross-section 7 to the square cross-section 5 is shown in FIG. In this case, the cross-sectional area is A > B, and the ratio depends on the conditions, but if A is 100, then A:B = 100: (75 to 35), and the length of each section is
The ratio of l ₁ , l ₂ , and l ₃ is suitably about l ₁ :l ₂ :l ₃ =1:4:1.

The rectangular cross section 5 is preferably triangular or more, generally rectangular, and of course also includes those with minute radii at the corners. Generally, the outer surface is square, but if the nozzle wall thickness is large,
Only the inner surface may have a rectangular cross section.

In _addition to the above-mentioned embodiments _, as shown in _FIG . , a gradual deformation section of circular cross-section section 7, omitting section _l3 , and a gradual deformation section of section 6.
The present invention includes nozzles in which the hose attachment side has a circular cross section and the discharge side tip has a square cross section, such as those in which a cross-sectional area changing section is provided in a section other than ₃ .

Furthermore, in this embodiment, a short tube 8 made of a flexible material such as rubber is attached to the tip of the square cross section 5.
It is used as a discharge part for mixed fluid pumped material such as concrete. The short tube 8 has a circular cross section and has a function to be described later, but the tip of the rectangular cross section 5 may of course be used as a discharge port.

The present invention has the above-mentioned configuration, in which the pipe line 2 is connected to the circular section 7 through the joint 3, and a predetermined water-cement ratio and slump value are supplied to the pipe line 2 from a supply means such as a pump. It is used for construction work in which wet concrete is pumped, compressed air is added before the spray nozzle 1, and the air is sprayed onto the construction surface. In this case, the centrifugal force due to the swirling flow acts on the wet concrete up to the circular cross section 7, but beyond that, the gradually deformed section 6l ₂ and the square cross section 5l ₁ form a square cross section between the discharge ports 4. Because there are
In this part, the swirling energy is weakened and converted into a straight flow, so that the concrete is given directionality and is injected from the discharge part in a converged state.

As a result, the range of diffusion of concrete becomes smaller, and dust with a light specific gravity reaches the construction surface while being entrained in the main stream of jetting, so that the generation of dust is reduced.

In addition, the rectangular cross section 5 prevents the concrete from stagnation, and since the rectangular cross section 5 has a smaller cross-sectional area than the rear circular cross section 7 and converges the concrete and injects it, compressed air can be used as a conveying medium. The loft effect causes the paste to be rolled up and merged with the main stream, resulting in less flow at the bottom of the tube and less sag.

Furthermore, when a flexible short tube 8 is attached to the discharge part as shown in the figure, the short tube 8 causes a kind of chatter vibration due to the concrete injection pressure, and this vibration causes the bottom flow of the tube that has reached the discharge port to flow into the discharge main stream. Since the splashing phenomenon continues, the occurrence of sag is more reliably prevented.

In addition, since the short cylinder 8 is highly elastic, the adhesion of paste particles is reduced due to the so-called self-sweeping effect caused by vibration, and as a result, even if fluctuations in injection pressure occur, troubles such as clogging of the discharge port can be avoided. Furthermore, the discharge section can be easily cleaned after spraying by applying an external shock to the short tube 8.

The nozzle for spraying concrete according to the present invention does not exclude structures in which an admixture, compressed air, or water addition section is installed at a certain position in the longitudinal direction.
Of course, the present invention can also be applied to a remote-controlled spray nozzle held in a holder at the tip of a boom or arm.

Furthermore, the spraying target is not limited to the above-mentioned concrete, but can be applied to various types of materials such as mortars, paints, fireproof coating materials, etc., as long as they have mixed fluidity and are forced and sprayed through a tubular path.

《Effects of the invention》 As explained above, when using the present invention, the simple structure can reliably prevent the generation of dust and the sagging of the paste, and it is possible to perform spraying construction such as concrete, which reduces material loss in a good working environment. Excellent effects such as being able to perform

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing an embodiment of the spray nozzle according to the present invention, Fig. 2 is a sectional view of the rear end of the nozzle shown in Fig. 1, and Fig. 3 is a gradual change from a round cross section to a square cross section. A cross-sectional view of the deformed section, and FIG. 4 is a cross-sectional view of the discharge port. FIG. 5 is a perspective view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Spray nozzle, 2... Pipeline, 5... Square cross section, 6... Gradually deformed section section, 7... Circular cross section, 8... Flexible short tube.

Claims (1)

[Scope of utility model registration request] A cylindrical body that is connected to the tip of a conduit having a circular cross section that pumps a mixed fluidized propellant such as concrete or mortar, and sprays the propellant onto a construction surface, the tip of the cylindrical body A spray nozzle for pressurized injection material, characterized in that a predetermined range of is formed in a rectangular cross-section having a smaller cross-sectional area than the pipe line.