JP3833283B2 - Nozzle for shot blasting - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a shot blast nozzle, and more particularly to a shot blast nozzle that can change the angle of the nozzle portion in accordance with the position of the processing portion.
[0002]
[Prior art]
Ejector system with a nozzle inlet using granular dry ice as a shot blasting device for cleaning operations such as removal of oil adhering to the surface of various articles, peeling of coating films, removal of mold release agents, etc. Things are known. The nozzle part in the nozzle part inlet ejector type shot blasting apparatus usually has a structure as shown in FIG.
[0003]
This shot blast nozzle includes a straight tubular inner tube 1 and an outer tube 2 provided coaxially with the inner tube 1, and a shot material flow in which dry ice as a shot material flows in the inner tube 1. A path 3 is formed between the inner tube 1 and the outer tube 2 in an acceleration gas flow path 4 through which an acceleration gas, for example, air, flows, and a ring-shaped narrow slit is formed at the tip of the acceleration gas flow path 4. It has a structure with an opening 5, and the shot material flowing out from the inner tube 1 is sucked by the ejector action of the acceleration gas that is throttled by the slit-like opening 5 and ejected at high speed, and the shot material is accelerated to be targeted It is comprised so that it may inject to the process part of a thing.
[0004]
In addition, a screw portion 7 for mounting the arcuate curved tube 6 is provided on the inner periphery of the distal end portion of the outer tube 2, and by mounting the curved tube 6 of an appropriate angle to the screw portion 7, The straight nozzle is used to perform the work of the processing unit that hardly ejects the shot material. For example, when the shot material is sprayed to the front corner 8a of the box-shaped or groove-shaped article 8 as shown in FIG. 10, the curved tube 6a of approximately 90 degrees is attached.
[0005]
[Problems to be solved by the invention]
However, since the conventional curved tube 6 uses a tube having a normal appropriate bending angle, for example, a 45 ° elbow or a 90 ° elbow, it is sucked into the acceleration gas at the nozzle tip and entrained by the acceleration gas. Since the shot material flows along the outer peripheral portion of the inner surface of the bending tube 6, as shown in FIG. 10, the shot material S injected from the tip of the bending tube 6 is in an eccentric state on the outer peripheral side of the bending tube 6a. Therefore, compared to the case where the shot material is ejected from the linear nozzle portion, when the curved tube 6 is used, the shot area of the shot material is reduced, and the peeling performance of the coating film is significantly lowered. In addition, the shot material's jet energy may be reduced due to a decrease in the speed of the shot material due to friction when the shot material collides with the inner surface of the curved tube 6, or due to collision with the wall surface or collision between shot materials. Also, the decrease in the coating film performance, such as the peeling performance of the coating film.
[0006]
Therefore, an object of the present invention is to provide a shot blast nozzle that can efficiently perform a cleaning operation of a portion that is difficult to work with a linear nozzle.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the shot blast nozzle of the present invention is for accelerating shot material from the flow path of the inner pipe of the double pipe consisting of the inner pipe and the outer pipe, and from the flow path between the inner pipe and the outer pipe . In the shot blast nozzle configured to supply each gas and eject the mixture of the shot material and the accelerating gas by an ejector action at the tip of the nozzle, the main pipe made of a straight double pipe is also straight A nozzle tube composed of a double tube , and a plurality of curved double tubes with different bending angles disposed between the nozzle tube and the main tube, the main tube being a straight tubular inner tube The nozzle tube is formed of a straight tubular inner tube and an outer tube coaxially formed on the outer periphery of the inner tube. The nozzle portion is extended by extending the tip of the outer tube from the inner tube. And, wherein the nozzle portion has a slit-like opening of the narrow ring-shaped in order to effectively generate an ejector effect which is formed between the tip of the outer tube surface and the inner tube, wherein each curved double Each of the pipes has an inner pipe and an outer pipe having the same curvature and the same angle formed as a double pipe through a spacer, and each of the inner pipe and each outer pipe is a pipe body having the same diameter. Both flow paths communicate with the distal ends of the inner tube and the outer tube, the proximal ends of the inner tube and the outer tube of the nozzle tube, and both ends of the inner tube and the outer tube of the curved double tube, respectively. Each of the plurality of curved double pipes is disposed between the nozzle pipe and the main pipe, and the inner pipes are connected to each other via the connection parts. It is characterized by connecting the outer tubes in an airtight manner.
[0008]
[Operation]
According to the above configuration, even if the shot material flowing in the curved double pipe portion flows somewhat eccentrically, the shot material is accelerated and injected by the acceleration gas injected from the nozzle portion of the nozzle tube, so that the shot material is injected from the tip of the nozzle tube. The amount of eccentricity of the shot material is very small compared to the case of using a conventional tube body such as an elbow, and sufficient performance can be obtained even when a curved double tube having a large bending angle is used.
[0009]
【Example】
Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings.
1 to 6 show an embodiment of a shot blasting nozzle according to the present invention, and FIGS. 7 and 8 show other shapes of connecting portions. The description will be made mainly with reference to FIG. 1, and in FIGS. 2 to 4, only the main parts are denoted by reference numerals.
[0010]
First, FIG. 1 to FIG. 3 show curved double tubes 30a, 30b having different bending angles between a main tube 10 made of a straight double tube and a nozzle tube 20 also made of a straight double tube. FIG. 4 shows a state in which the main pipe 10 and the nozzle pipe 20 are directly connected without attaching a curved double pipe.
[0011]
The main pipe 10 is formed of a double pipe comprising a straight tubular inner pipe 11 and an outer pipe 12 provided coaxially on the outer periphery of the inner pipe 11. An accelerating gas channel 14 through which an accelerating gas flows between the flowing shot material channel 13 and the inner tube 11 and the outer tube 12, each channel 13, 14 being a predetermined dry ice supply source and accelerating gas supply, respectively. Connected to a source (not shown).
[0012]
As shown in FIGS. 5 and 6, the inner tube 11 and the outer tube 12 are fixed via a plurality of spacers 15 and 15 provided so as not to obstruct the flow of the acceleration gas. Further, flanges 16a and 16b for connecting curved double pipes and the like are provided on the outer periphery of the end portions of the inner tube 11 and the outer tube 12, respectively, and each end face of the flanges 16a and 16b has an airtight holding O. Annular grooves 18a and 18b for mounting the rings 17a and 17b are provided, respectively.
[0013]
Similarly to the main tube 10, the nozzle tube 20 includes a straight tubular inner tube 21 and an outer tube 22 provided coaxially on the outer periphery of the inner tube 21, and the inside of the inner tube 21 is shot material. An acceleration gas flow path 24 is formed between the flow path 23 and the inner pipe 21 and the outer pipe 22. Further, the inner tube 21 and the outer tube 22 are fixed via the same spacers 15 and 15 as described above, and O-rings 17a and 17b are attached to the outer periphery of the end portions of the inner tube 21 and the outer tube 22, respectively. Connecting flanges 16a and 16b provided with grooves 18a and 18b are provided, respectively.
[0014]
The outer tube 22 has a distal end longer than the inner tube 21 and is formed in a stepped shape having a small diameter from a position corresponding to the distal end of the inner tube 21. Between the two, a ring-shaped and narrow slit-shaped opening 29 for effectively generating the ejector action is formed. Further, the distal end portion of the inner tube 21 is formed thin in consideration of the suction / mixing action of the shot material by the acceleration gas ejected from the outer tube 22.
[0015]
The curved double pipes 30a, 30b, 30c are formed by forming inner pipes 31a, 31b, 31c and outer pipes 32a, 32b, 32c having the same curvature and the same angle into a double pipe through spacers 15, 15, respectively. The inner pipes 31a, 31b, 31c are the shot material flow path 33, and the accelerating gas flow path 34 is between the inner pipes 31a, 31b, 31c and the outer pipes 32a, 32b, 32c. Also, the same connecting flanges 16a and 16b are provided at both ends of each of the inner pipes 31a, 31b and 31c and the outer pipes 32a, 32b and 32c.
[0016]
Each inner pipe and outer pipe are pipe bodies having the same diameter, and a flange provided in each pipe and an annular groove for mounting an O-ring are also formed in the same shape. Therefore, as shown in each figure, when the main pipe 10, the nozzle pipe 20 and the curved double pipes 30a, 30b, 30c are connected, the flanges 16a, 16a come into contact with each other and the shot material flow paths 13, 23, 33, and The acceleration gas flow paths 14, 24, and 34 communicate with each other, and the air flow between the flow paths and the outside are kept airtight by O-rings 17a and 17b. Further, the connection and fixing of the flanges 16a and 16a can be performed by known fixing means such as the clamp 41.
[0017]
In this way, the main pipe 10, the nozzle pipe 20, and the curved double pipes 30a, 30b, and 30c having different bending angles are formed in a double pipe structure having the same diameter, and the connection portions are formed in the same shape. As shown in FIG. 1, a shot blast nozzle having a bending angle of about 30 degrees is shown in FIG. 2 if a curved double pipe 30a having a bending angle of about 30 degrees is mounted between the main pipe 10 and the nozzle pipe 20. When the curved double tube 30b is mounted, a shot blast nozzle having a bending angle of 45 degrees is obtained, and when the curved double tube 30c shown in FIG. 3 is mounted, a shot blast nozzle having a bending angle of 90 degrees is obtained. Further, if the main pipe 10 and the nozzle pipe 20 are directly connected as shown in FIG. 4, a straight shot blast nozzle can be obtained.
[0018]
In the shot blast nozzle (curved nozzle) in which the curved double tubes 30a, 30b, and 30c are mounted between the main tube 10 and the nozzle tube 20 as described above, the shot material flow path 13 of the main tube 10 is supplied. The shot material flows through the curved double pipes 30a, 30b, 30c and the shot material flow path 13 in the nozzle tube 20, and is sucked and accelerated by the acceleration gas at the tip of the inner tube 21 of the nozzle tube 20, together with the acceleration gas. The nozzle tube 20 is sprayed linearly from the tip.
[0019]
Therefore, since the accelerated shot material does not flow through the curved portion, the shot material is not decentered, and the shot material can be uniformly injected from the tip of the nozzle tube 20. Furthermore, since there is almost no collision with the inner surface of the curved portion or between shot materials, performance close to that of a linear nozzle can be obtained.
[0020]
Next, an experiment for confirming the performance of the curved nozzle having the structure shown in the above embodiment will be described. First, as an object to be treated, a commercially available acrylic paint spray can (Atom spray manufactured by Atom Chemical Paint Co., Ltd.) was used to form a coating film on the surface of an iron plate and left to dry for one day. Using. And the peeling test of a coating film was done for the distance of a nozzle front-end | tip and the surface of an iron plate as about 10 cm. The coating thickness at this time was about 13 μm on average.
[0021]
The performance comparison of each nozzle is based on the time taken for a normal linear nozzle to peel off the coating film in the range of 10 cm × 15 cm, and the coating area that could be peeled off by each nozzle in the same time. The measurement was performed by calculating the ratio of each peeled area with the linear nozzle as 100%.
[0022]
Each condition in shot blasting was as follows.
Nozzle outlet inner diameter: 20 mm
Accelerating gas: pressure 6 kgf / cm ² G, flow rate of about 5 m ³ / min compressed air shot material: dry ice pellets 3 mm in diameter x 5 mm in length [0023]
As a result, the coating film having an area of 85% is peeled off by the curved nozzle of about 30 degrees shown in FIG. 1, 71% by the curved nozzle of 45 degrees shown in FIG. 2, and 60% by the curved nozzle of 90 degrees shown in FIG. I was able to. On the other hand, in the case of the conventional nozzle having the structure shown in FIG. 9, when the bending angle of the bending tube 6 is 30 degrees, only 5%, 3% at 45 degrees, and 1-2% at 90 degrees are peeled off. I could not.
[0024]
FIGS. 7 and 8 show other embodiments of the connecting portion, for example, showing the connecting portion between the main pipe 10 and the curved double tube 30a. The structure of the connecting portion shown in FIG. 7 is provided with enlarged diameter portions 11a and 12a at the distal ends of the inner tube 11 and the outer tube 12 of the main tube 10, respectively, and the inner tube 31a and the outer tube 32a of the curved double tube 30a. The base end is formed so that it can be inserted, and the O-rings 17c and 17d are mounted at appropriate positions of the contact portions of the two, and the flanges 16c provided on the outer periphery of the ends of the outer pipes 12 and 32a are attached and detached with bolts The connection is made possible.
[0025]
Further, the structure of the connecting portion shown in FIG. 8 is provided with a screw portion 43 that is screwed to the distal end portion of the outer tube 12 of the main tube 10 and the proximal end portion of the outer tube 32a of the curved double tube 30a. In addition to screw coupling, O-rings 17e and 17f are mounted at appropriate positions of the contact portions of the two.
[0026]
As described above, the structure of the connecting portion of each pipe can adopt an arbitrary structure according to, for example, the diameter of the pipe, and the fixing method of the inner pipe and the outer pipe is also made of gas or shot material. Any structure can be adopted as long as the flow is not obstructed, and the bending angle of the curved double tube can also be set arbitrarily.
[0027]
【The invention's effect】
As described above, the shot blast nozzle of the present invention is provided with a curved double tube having an appropriate bending angle in front of the nozzle that mixes and ejects the shot material and the acceleration gas, and is sucked by the acceleration gas. Since the accelerated shot material does not flow through the curved portion, the shot material can be uniformly ejected from the nozzle, and performance close to a linear nozzle can be exhibited.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a first embodiment of a shot blast nozzle according to the present invention.
FIG. 2 is a cross-sectional view showing a second embodiment.
FIG. 3 is a cross-sectional view showing a third embodiment.
FIG. 4 is a cross-sectional view showing a fourth embodiment.
FIG. 5 is an end view of the main pipe.
6 is a cross-sectional view taken along line VI-VI in FIG.
FIG. 7 is a cross-sectional view of a main part showing another embodiment of a connection part.
FIG. 8 is a cross-sectional view of a main part showing still another embodiment of the connection part.
FIG. 9 is a cross-sectional view showing an example of a conventional shot blast nozzle.
FIG. 10 is an explanatory diagram when a bending tube is used.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Main pipe, 11, 21, 31a, 31b, 31c ... Inner pipe | tube, 12, 22, 32a, 32b, 32c ... Outer pipe | tube, 13, 23, 33 ... Shot material flow path, 14.24, 34 ... Acceleration gas Flow path, 15 ... spacer, 16a, 16b ... flange, 17a, 17b ... O-ring, 18a, 18b ... annular groove, 20 ... nozzle tube, 29 ... slit-like opening, 30a, 30b, 30c ... curved double tube, 41 ... Clamp

Claims (1)

The shot material is supplied from the flow path of the inner pipe of the double pipe consisting of the inner pipe and the outer pipe, and the acceleration gas is supplied from the flow path between the inner pipe and the outer pipe, and the shot is made by the ejector action at the nozzle part at the tip. In a shot blast nozzle configured to jet a mixture of a material and an acceleration gas,
A main pipe made of a straight double pipe, a nozzle pipe made of the same straight double pipe , and a plurality of curved double pipes arranged between the nozzle pipe and the main pipe and having different bending angles , With
The main pipe is formed of a straight tubular inner pipe and an outer pipe provided coaxially on the outer periphery of the inner pipe,
The nozzle tube is formed of a straight tubular inner tube and an outer tube coaxially provided on the outer periphery of the inner tube, and the tip of the outer tube is extended from the inner tube to form the nozzle unit. The nozzle portion has a ring-shaped and narrow slit-shaped opening for effectively generating an ejector action formed between the inner surface of the outer tube and the tip of the inner tube.
Each of the curved double pipes forms an inner pipe and an outer pipe of the same angle with the same curvature through a spacer into a double pipe,
Each of the inner pipe and the outer pipe is a tubular body having the same diameter,
Both flow paths are provided at the distal ends of the inner tube and outer tube of the main tube, the proximal ends of the inner tube and outer tube of the nozzle tube, and both ends of the inner tube and outer tube of the curved double tube. Each is provided with a connecting part that can be attached to and detached from each other in a state of communication,
Any one of the plurality of curved double pipes is disposed between the nozzle pipe and the main pipe, and the inner pipes and the outer pipes are hermetically connected to each other through the connection portions. Nozzle for shot blasting.

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