JP4344933B2 - Blasting nozzle - Google Patents

Description

  The present invention relates to a blasting nozzle used for blasting, and more particularly to improvement of a blasting nozzle having a rectangular injection port shape.

  A blasting nozzle having an injection port having a circular cross section, which is widely used as a blasting nozzle for blasting, has a relatively narrow width at which the blasting material is ejected during blasting nozzle scanning. Therefore, in a case where injection processing is performed over a wide range by a single nozzle scan, a blasting nozzle having an injection port having a rectangular cross section in which the injection port is widened is used. However, in this blasting nozzle, since the density of the spray material becomes small at both edges of the spray port, it is very difficult to perform the spray process with uniform pressure over the entire width of the spray port.

  As a blasting nozzle for the purpose of making up for the drawbacks of the blasting nozzle having an injection port having a rectangular cross section, there is one disclosed in Patent Document 1. The nozzle for blasting is provided with an injection material flow path having a wide side surface having a divergent expansion portion inside the nozzle tip (nozzle body) and a narrow side surface perpendicular to the wide side surface, and its tip Is provided with a rectangular injection port. In the vicinity of the injection port in the injection material flow path, there is provided a width direction throttle that rapidly narrows the injection port into an elongated slit shape, and the spindle tip and the flow direction of the injection material are arranged inside the nozzle tip. A triangular guide member to be converted is provided. What is configured as described above is that the injection material is dispersed in the longitudinal direction of the rectangular injection port by the spindle-shaped piece, and the injection material dispersed thereby is moved inward by the triangular guide member to perform the injection processing. To do.

However, as a result of intensive studies, the present inventors have found that the blasting nozzle has the following problems. That is, in the blasting nozzle, the spray material channel is simply widened in the form of a wide end on the wide side surface, and the width of the narrow side surface orthogonal to the wide side surface remains constant until it comes close to the injection port. is there. Thus, widening only one of the side surfaces only increases the cross-sectional area of the injection material passage, and the injection material cannot be dispersed in the lateral direction (the direction of the narrow side surface). Therefore, it is necessary to dispose the spray material in the lateral direction by arranging a thick spindle-shaped piece upstream of the spray material flow path. However, since there is a shortage of the injection material immediately below the spindle-shaped piece, a pair of triangular guide members are arranged opposite to the left and right ends of the wide side surface to change the flow of the injection material inward. There was a need. As a result, it has been found that there is a problem that the injection material concentrates near the outlet of the triangular guide member and the workpiece is locally deeply beaten. Thus, the conventional blasting nozzle having an injection port having a rectangular cross section is not sufficiently satisfactory in the uniformity of the injection processing.
JP 2002-144239 A (FIG. 1)

  The present invention has been made in order to solve the problems of the conventional blasting nozzle described above and to provide a blasting nozzle having a rectangular injection port that can uniformly blast a workpiece over a wide width. Is.

The blasting nozzle of the present invention, which has been made to solve the above problems, is an injection having a wide side surface and a narrow side surface orthogonal to the wide side surface inside a nozzle tip having an elongated rectangular injection port at the tip. A material flow path is provided, the wide side surface is gradually widened from the nozzle tip mouth to the tip of the nozzle chip, and the narrow side surface is gradually reduced in accordance with the wide side of the wide side surface. And a plurality of dispersion rods for dispersing the injection material in the upstream portion of the injection material flow path at right angles to the wide side surface , on the downstream side of the dispersion rod, An averaging rod for further uniformly dispersing the propellant is arranged perpendicular to the dispersion rod .

The injection material flow path is composed of an upstream flow path whose wide side face is widened at a constant inclination angle and a downstream flow path whose wide side face is widened at a larger inclination angle than the upstream flow path. be able to. In addition, a run-up pipe for rectifying a solid-gas two-phase flow in which air and propellant are mixed is connected to the mouth of the blasting nozzle, and air and propellant are mixed upstream of the run-up pipe. It is possible to provide a blasting nozzle by disposing a mixing chamber.

  In the blasting nozzle of the present invention, the injection material flow path inside the nozzle tip is composed of a wide side surface and a narrow side surface orthogonal to the wide side surface, and the wide side surface extends from the nozzle tip mouth to the nozzle tip tip. The width was gradually widened, and the narrow side surface was gradually reduced corresponding to the wide side surface. In other words, the narrow side surfaces of the two opposing surfaces are spaced apart in an eight shape toward the downstream, and the wide side surfaces of the two opposing surfaces are approached in a reverse eight shape toward the downstream, so An increase in area can be suppressed. And since the several dispersion | distribution rod was provided in the upstream part of the injection material flow path orthogonally to the wide side surface, an injection material can be disperse | distributed to the direction of a narrow side surface. Further, since the averaging rod is arranged on the downstream side of the dispersion rod in a direction orthogonal to the dispersion rod, the spray material can be dispersed in the direction of the wide side surface.

  Further, the injection material flow path is composed of an upstream flow path whose wide side surface is widened at a constant inclination angle, and a downstream flow path whose wide side surface is widened at a larger inclination angle than the upstream flow path, The left and right narrow side surfaces of the downstream channel are widened outward from the upstream side, so that the spray material is never squeezed inward, thus preventing the occurrence of strongly processed parts due to local concentration of the spray material. can do.

  Further, since the blasting nozzle is composed of a mixing chamber for mixing air and a spray material, a mixed solid-gas two-phase flow running tube, and a nozzle tip, The spray material can be supplied to the nozzle tip after the density of the spray material is made uniform and the solid-gas two-phase flow is rectified.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
1 and 2 are diagrams showing a blasting nozzle according to the present invention, wherein 1 is a supply pipe for an injection material and air, 2 is a mixture of the injection material and air supplied from the injection material supply pipe 1, and is solid A mixing chamber 3 for forming a gas two-phase flow is a running tube 3 connected to the mixing chamber 2 for rectifying the solid-gas two-phase flow. The propellant is directed to the work beyond the running tube 3. A nozzle tip 4 for spraying is attached.

  The nozzle chip 4 is composed of a main portion 5 whose outer shape is widened toward the end, and a tip portion 7 which is formed thinner than the main portion 5 and provided with an elongated rectangular injection port 6. Inside the nozzle tip 4, an injection material flow path 8 is formed from the nozzle tip base 4 a to the injection port 6 through the main portion 5 and the tip portion 7. In the spray material flow path 8, the mouth 4 a connected to the run-up pipe 3 has a square cross section. From the mouth 4 a to the spray port 6, two opposed wide side surfaces 8 a and orthogonal to the wide side surface 8 a. And two narrow side surfaces 8b facing each other.

  The width of the wide side surface 8a is gradually widened in a divergent shape from the mouth 4a to the injection port 6. That is, the two narrow side faces 8b facing each other are gradually separated downward in an eight-letter shape. On the other hand, the width of the narrow side surface 8b is gradually reduced downward. That is, the two wide side surfaces 8a facing each other are gradually approached in the shape of an inverted octave downward. The approach of the two wide side surfaces 8a can suppress an increase in the cross-sectional area of the injection material flow path, and the injection material is made to collide with the wide side surface 8a inclined inward to cause the injection material to flow. Can be dispersed within.

  In this injection material flow path 8, the wide side surface 8 a is widened by setting the upstream side flow path 81 where the wide side surface 8 a is widened at a constant tilt angle and the inclination angle larger by β than the tilt angle of the upstream side flow path 81. A downstream flow path 82. That is, since the angle of the narrow side surface 8b on the downstream side is changed outward from the upstream side, the injection material is not brought inward by collision with the narrow side surface 8b. Since the injection material flow path 8 is formed in the nozzle chip 4 as described above, the injection material is naturally and uniformly distributed over the entire cross section of the injection material flow path 8, and thus a guide member or the like is used. There is no need to change the flow direction of the spray material abruptly. The angle β is preferably 0 ° to 15 °. This is because if the negative angle is less than 0 °, the flow of the injection material is redirected inward, and if it exceeds 15 °, waste of air increases due to an increase in the cross-sectional area of the flow path.

  Since three dispersion rods 10 are provided in the vicinity of the mouth 4a inside the injection material flow path 8 so as to be orthogonal to the wide side surface 8a, the dispersion material 10 causes the injection material to move in the direction of the narrow side surface 8b. Can be dispersed. The shape of the dispersion rod 10 is not particularly limited, but is preferably a cylinder. The thickness is preferably less than φ1 to less than φ10 mm, and more preferably φ5 mm, when the injection port 6 has a wide width of 50 to 300 mm and a narrow width of 1 to 5 mm. This is because if the diameter is smaller than φ1 mm, the dispersion effect of the spray material is not sufficient, and if it is thicker than φ10, the density of the spray material becomes thin immediately below the dispersion rod 10. Further, it is desirable to use a plurality of branch bars 10 and to increase the number of the downstream side from the upstream side, and it is appropriate that the number is three.

  Further, since the averaging rod 11 is disposed on the downstream side of the dispersion rod 10 so as to be orthogonal to the dispersion rod 10, the injection material can be dispersed in the direction of the wide side surface 8a by the averaging rod 11. The shape of the homogenizing rod 11 is not particularly limited, but is preferably a cylinder. Further, the thickness may be the same as that of the dispersion rod 10. Two of the uniformizing bars 11 can be arranged vertically with a required interval.

  In the blasting nozzle configured as described above, the injection material sent from the injection material supply pipe 1 is uniformly mixed with air in the mixing chamber 2 to form a solid-gas two-phase flow. Next, the solid-gas two-phase flow is rectified into a normal flow without a vortex flow in the run-up pipe 3 and sent to the injection material flow path 8 in the nozzle tip 4. Since the spray material flow path 8 has a wide side surface 8a widened toward the bottom and a narrow side surface 8b orthogonal to the wide side surface 8a is contracted to correspond to the wide width of the wide side surface 8a, the flow path is cut off. Air pressure loss can be suppressed by suppressing an increase in area. Further, the spray material can collide with the wide side surface 8 a inclined inward and can be dispersed in the spray material flow path 8. Furthermore, since the downstream side of the injection material flow path 8 is widened with a greater inclination than the upstream side, there is no rebounding of the injection material to the inside by the narrow side surface 8b. In addition, since a plurality of dispersing rods 10 and averaging rods 11 are arranged in the spray material flow path 8, the spray material can be evenly leveled by these. Accordingly, it is possible to uniformly spray the spray material from the rectangular spray port provided at the tip of the nozzle tip.

The blasting nozzle of the present invention will be described in detail below based on the test results.
FIG. 3 is a diagram showing the results of testing the influence of the shape of the injection material flow path 8 on the uniformity of the injection processing. FIG. 3A shows a case where the narrow side surface 8b of the downstream channel 82 is vertical, and deep strong processed portions are generated at both ends of the injection port (arrows). FIG. 3b shows the case where the slope of the narrow side surface 8b on the downstream side is the same as that on the upstream side, but the strongly processed portion is shallow. Further, as shown in FIG. 3c, when the narrow side surface 8b on the downstream side is directed outward from the upstream side, the occurrence of a strongly processed portion is hardly suppressed.

  FIG. 4 shows the effect of the dispersion bar 10. 4a shows the case where there is no dispersion bar 10, FIG. 4b shows the case where there is one dispersion bar 10, FIG. 4c shows the case where there are three dispersion bars 10, and FIG. 4d shows the case where there are five dispersion bars 10. The case where three dispersion rods 10 are arranged in the shape of Yakura is the best result with a wide uniform processing area.

  FIG. 5 shows the effect of the averaging rod 11. Compared with only the dispersion rod 10 of FIG. 5a, it can be seen that when the averaging rod 11 of FIG. Further, FIG. 6 shows the effects of the mixing chamber 2 and the run-up tube 3, but it can be seen that the mixing chamber 2 and the run-up tube 3 are very effective in making the injection process uniform. The length of the run-up tube 3 is desirably 50 mm or more. This is because if the length is less than 50 mm, the flow cannot be sufficiently rectified.

  As described above, the blasting nozzle of the present invention does not cause a sudden change of direction of the flow of the spray material in the vicinity of the spray port, so that the spray material can be sprayed uniformly over the entire surface of the spray port. It is possible to prevent the generation of locally strong processed parts as in the prior art. Therefore, the blasting nozzle of the present invention has great industrial value as being capable of uniformly performing the injection processing with high efficiency.

It is a fragmentary sectional view of the front of the nozzle for blasting of this invention. It is a fragmentary sectional view of the side of the nozzle for blasting of the present invention. It is a graph which shows the influence which the shape of an injection material flow path has on the uniformity of injection processing. It is a graph which shows the effect of a dispersion bar. It is a graph which shows the effect of an averaging bar. It is a graph which shows the effect of a mixing room and a run-up pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection material supply pipe 2 Mixing chamber 3 Run-up pipe 4 Nozzle tip 4a Nozzle tip mouth 5 Main part 6 Injection port 7 Tip part 8 Injection material channel 8a Wide side surface 8b Narrow side surface 81 Upstream channel 82 Downstream channel 10 Dispersion bar 11 Averaging bar

Claims (3)

An injection material flow path having a wide side surface and a narrow side surface orthogonal to the wide side surface is provided inside the nozzle chip having an elongated rectangular injection port at the tip, and the wide side surface is gradually extended from the nozzle tip mouth to the nozzle tip tip. The narrow side surface is gradually reduced in correspondence with the wide side surface widening, and this injection material passage is communicated with the rectangular injection port at the tip, and the upstream portion of the injection material passage In addition, a plurality of dispersing rods for dispersing the propellant are provided perpendicular to the wide side surface , and an averaging rod for dispersing the propellant further uniformly is perpendicular to the dispersing rod on the downstream side of the dispersing rod. Blasting nozzle characterized by being arranged in the same manner. The injection material flow path is composed of an upstream flow path whose wide side surface is widened at a constant inclination angle and a downstream flow path whose wide side surface is widened at a larger inclination angle than the upstream flow path. The nozzle for blasting according to 1. A run-up pipe for rectifying a solid-gas two-phase flow in which air and propellant are mixed is connected to the mouth of the nozzle tip, and a mixing chamber for mixing air and propellant is installed upstream of the run-up pipe. The blasting nozzle according to claim 1 or 2, wherein the blasting nozzle is provided.

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