JP2024063605A - Air Injection Nozzle - Google Patents

Abstract

To provide an air injection nozzle capable of suppressing deviation of injection air in the extending direction of an injection port.SOLUTION: In the air injection nozzle, an upstream wall 23 is provided so as to cover one of a pair of openings formed by each main plate 21 and each side wall 22A, 22B. The other of the openings is a long injection port extending in the facing direction of the side wall 22A, 22B. An inlet 24 is formed in the center of the upstream wall 23 in the facing direction of the side wall 22A, 22B. In a space surrounded by each main plate 21, each side wall 22A, 22B, and the upstream wall 23, first and second partition plates 41 and 42 are provided so as to divide and guide air having flown in through the inlet 24 to the injection port. The first and second partition plates 41 and 42 are provided with a plate surface directed to each side wall 22A, 22B.SELECTED DRAWING: Figure 4

Description

The present invention relates to an air injection nozzle that blows away dust by injecting air from an inlet and ejecting it from an outlet.

As described in Patent Document 1, a conventional injection nozzle is known that injects powder and gas from an inlet through an injection port. The injection port of this injection nozzle is long. A guide block is provided inside the injection nozzle to prevent the powder from being biased in the direction in which the injection port extends.

Japanese Patent Application Laid-Open No. 11-333725

Some spray nozzles blow away dust adhering to the object to be cleaned by injecting air from an inlet and spraying it from an outlet. In this case, no powder is used, so there is no need to provide a guide block in the spray nozzle to prevent the powder from being biased. Although air spray nozzles do not cause the problem of powder being biased, they can cause air bias in the direction the nozzle extends. For this reason, there is still room for improvement in the technology to prevent air bias.

The main objective of the present invention is to provide an air injection nozzle that can suppress bias in the direction in which the injection nozzle extends.

The present invention relates to an air injection nozzle that blows away dust by injecting air from an inlet through an injection port,
A pair of main plate portions arranged with plate surfaces facing each other;
A side wall portion connecting side edges of the main plate portions to each other;
an upstream wall portion provided to close one of a pair of openings formed by the main plate portions and the side wall portions;
Equipped with
The other of a pair of openings formed by the main plate portions and the side wall portions is the injection port having an elongated shape extending in a direction in which the side wall portions face each other,
The inlet is formed in a middle portion of the upstream wall portion in a direction in which the side wall portions face each other,
a plurality of partition plate portions provided in a space surrounded by the main plate portions, the side wall portions, and the upstream wall portion, extending from the inlet side toward the outlet side, and dividing the air flowing in from the inlet and directing it to the outlet,
As the plurality of partition plate portions,
a first partition plate portion extending from the inlet side toward one side with respect to a center of the injection port in a direction in which the side wall portions face each other;
a second partition plate portion extending from the inlet side toward the other side with respect to a center of the injection port in a direction in which the side wall portions face each other;
Equipped with
The first partition plate portion and the second partition plate portion are provided with their plate surfaces facing the side wall portion.

In the present invention, an inlet is formed in the middle of the upstream wall in the direction in which the side wall portions face each other. Air flows from the inlet into the space surrounded by the main plate portions, the side wall portions, and the upstream wall portion. The air that flows in is sprayed from an elongated nozzle that extends in the direction in which the side wall portions face each other.

In the space surrounded by the main plate parts, the side wall parts, and the upstream wall part, a plurality of partition plate parts are provided that extend from the inlet side toward the nozzle side and divide the air flowing in from the inlet and guide it to the nozzle. The plurality of partition plate parts include first and second partition plate parts. The first partition plate part extends from the inlet side toward one side of the center of the nozzle in the direction in which the side wall parts face each other. The second partition plate part extends from the inlet side toward the other side of the center of the nozzle in the direction in which the side wall parts face each other. This allows the air flowing in from the inlet to be guided to the nozzle so as to suppress the occurrence of bias in the injected air in the direction in which the nozzle extends. In addition, the first and second partition plate parts are provided with their plate surfaces facing the side wall parts. Therefore, the area of the first and second partition plate parts when viewed from the inlet can be reduced, and the noise generated when air collides with the first and second partition plate parts can be reduced.

In this way, the present invention can reduce noise while suppressing bias in the direction in which the nozzle extends.

FIG. FIG. FIG. Cross-sectional view taken along line 4-4 in Figure 2. Cross-sectional view taken along line 5-5 in Figure 1. FIG. 2 is a view of the inlet from the outside of the upstream wall. FIG. 4 is a cross-sectional view of an air injection nozzle according to Comparative Example 1. FIG. 11 is a cross-sectional view of an air injection nozzle according to Comparative Example 2. FIG. 11 is a cross-sectional view of an air injection nozzle according to Comparative Example 3.

One embodiment of the air injection nozzle according to the present invention will be described below with reference to the drawings. The air injection nozzle blows away dust adhering to the object to be cleaned by injecting air from an inlet through an injection port.

As shown in Figures 1 to 5, the air injection nozzle 10 is box-shaped and includes a main body 20 in which an air inlet 24 is formed, and a nozzle 30 in which an injection port 31 that is connected to the main body 20 and in which an injection port 31 for injecting air is formed. The main body 20 and the nozzle 30 are made of, for example, a steel plate, and include a pair of main plate portions 21, a first side wall portion 22A, a second side wall portion 22B, and an upstream wall portion 23 that are rectangular plate-shaped.

The main plate portions 21 are arranged with their plate surfaces parallel to one another. One side edge portion of each of the main plate portions 21 is connected to the other side edge portion of each of the main plate portions 21 by a plate-shaped first side wall portion 22A. The other side edge portion of each of the main plate portions 21 is connected to the other side edge portion of each of the main plate portions 21 by a plate-shaped second side wall portion 22B. The side wall portions 22A, 22B are arranged with their wall surfaces parallel to one another.

Both ends of each main plate 21 and each side wall 22A, 22B are openings. A rectangular plate-shaped upstream wall 23 is provided to close one of the pair of openings. An inlet 24 is formed through the upstream wall 23 at the center of the upstream wall 23 in the direction in which the side walls 22A, 22B face each other (hereinafter, width direction). In this embodiment, the inlet 24 is circular. The diameter D of the inlet 24 is smaller than the dimension L1 of the upstream wall 23 in the wall height direction (in other words, the distance between the inner surfaces of the pair of main plate sections 21 in the main body 20).

The other of the pair of openings formed by each main plate portion 21 and each side wall portion 22A, 22B is an elongated injection port 31 extending in the width direction (see FIG. 3). The injection port 31 is formed in the width direction from the first side wall portion 22A to the second side wall portion 22B. The center of the injection port 31 faces the inlet port 24 in the direction in which each side wall portion 22A, 22B extends. The part of each main plate portion 21 and each side wall portion 22A, 22B on the injection port 31 side is the nozzle portion 30. The nozzle portion 30 is a portion where the distance between each main plate portion 21 becomes smaller as it approaches the injection port 31 side. In other words, the air flow path area in the nozzle portion 30 becomes smaller as it approaches the injection port 31.

The dimension L2 of the nozzle 31 in the direction in which the main plate parts 21 face each other (hereinafter, the height direction) is set to, for example, 1/400 to 3/400 of the distance L1 between the inner faces of the pair of main plate parts 21 in the main body part 20, and is preferably set to 1/250 to 1/200 of the dimension in the height direction of the main body part 20. For example, when the distance L1 between the inner faces is 20 mm, the dimension L2 of the nozzle 31 in the height direction is set to a dimension in the range of 0.08 mm to 0.1 mm. By setting "L1 x 1/400 ≦ L2 ≦ L1 x 3/400", it is possible to increase the flow rate of the injected air from the nozzle 31 while reducing noise, thereby improving the dust removal effect. It has been confirmed by experiments that when the dimension L2 of the nozzle 31 is set to a dimension larger than 3/400 of the distance L1 between the inner faces of the main plate parts 21, the effect of the muffler using the volume inside the air injection nozzle 10 is reduced and the noise increases. Furthermore, it has been confirmed through experiments that if the dimension L2 of the injection port 31 is set to a dimension greater than 3/400 of the distance L1 between the inner faces of the main plate portion 21, the flow rate of the air injected from the injection port 31 decreases, and the dust removal effect decreases. Also, if the dimension L2 of the injection port 31 is set to a dimension less than 1/400 of the distance L1 between the inner faces of the main plate portion 21, the flow rate of the air injected from the injection port 31 decreases, and there is a concern that the dust removal effect will decrease.

On the outer surface of the upstream wall 23, a tubular (specifically cylindrical) supply section 25 is provided for supplying air to the inlet 24. In this embodiment, the inner diameter of the supply section 25 is larger than the diameter D of the inlet 24. An air supply device is connected to the supply section 25 via an air supply pipe (not shown). Air supplied from the air supply device through the air supply pipe and the supply section 25 flows into the inside of the air injection nozzle 10 from the inlet 24, and the air that has flowed in is injected from the injection port 31. When an operator operates the air injection nozzle 10 so that the injection port 31 faces the object to be cleaned, dust attached to the object to be cleaned is blown away. The inner diameter of the supply section 25 may be the same dimension as the diameter of the inlet 24, for example.

As shown in FIG. 5, the angle θ between each main plate portion 21 in the nozzle portion 30 is set to an acute angle, specifically, to an angle in the range of 50° to 70°. This setting is for the purpose of reducing noise generated by air being sprayed from the nozzle 31. Unlike this embodiment, when the angle θ between each main plate portion 21 is set to 90°, it has been confirmed through experiments that the noise generated when air collides with the inner surface of the nozzle portion 30 increases. In contrast, it has been confirmed through experiments that a noise reduction effect is achieved by setting the angle θ to an acute angle. The angle θ between each main plate portion 21 may be preferably set to an angle in the range of 55° to 65° (for example, 60°).

The tip of the first side wall 22A on the nozzle 31 side is a first guide 32A extending in a direction from the inlet 24 side toward the nozzle 31 side with respect to the nozzle 31. Similarly, the tip of the second side wall 22B on the nozzle 31 side is a second guide 32B. Each guide 32A, 32B is provided to prevent air from dispersing outward in the width direction beyond each guide 32A, 32B and to increase the straightness of the air injected from the nozzle 31. This prevents a drop in pressure of the air injected from the nozzle 31 and improves the dust removal effect.

The air injection nozzle 10 is provided with a first partition plate portion 41 and a second partition plate portion 42 for dividing the air flowing in from the inlet 24 and directing it to the injection port 31, and suppressing bias of the injected air in the width direction of the injection port 31. Each partition plate portion 41, 42 has a rectangular (specifically, rectangular) plate shape and is made of, for example, a steel plate. Each partition plate portion 41, 42 is provided in a space surrounded by each main plate portion 21, each side wall portion 22A, 22B, and the upstream wall portion 23. As shown in FIG. 4, the first partition plate portion 41 extends from the center in the width direction of the upstream wall portion 23 toward the first side wall portion 22A side with respect to the center in the width direction of the injection port 31. The second partition plate portion 42 extends from the center in the width direction of the upstream wall portion 23 toward the second side wall portion 22B side with respect to the center in the width direction of the injection port 31. The distance between the first partition plate portion 41 and the second partition plate portion 42 in the width direction increases from the inlet 24 side toward the injection port 31 side. In a plan view of the plate surface of the main plate portion 21, the first partition plate portion 41 and the second partition plate portion 42 are disposed symmetrically with respect to a central axis that passes through the center of the inlet 24 and extends in the direction in which each side wall portion 22A, 22B extends.

Each partition plate portion 41, 42 is provided so as to intersect (orthogonally) with each main plate portion 21. Therefore, each partition plate portion 41, 42 is provided with its plate surface facing each side wall portion 22A, 22B. This makes it possible to reduce the area of each partition plate portion 41, 42 when viewed from the inlet 24. As a result, it is possible to reduce noise generated when air collides with each partition plate portion 41, 42. In addition, because each partition plate portion 41, 42 is plate-shaped, it is possible to increase the internal volume of the air injection nozzle 10. This makes it possible to increase the effect of the muffler using this internal volume, and thus to increase the noise reduction effect.

The first and second partition plate sections 41, 42 extend from one main plate section 21 to the other main plate section 21 over the entire length (see FIG. 5). The ends 41a, 41b of the first and second partition plate sections 41, 42 on the inlet 24 side have a tapered shape with a plate thickness that becomes thinner toward the inlet 24 side, as shown in FIG. 4. This allows the air flowing in from the inlet 24 to be smoothly diverted, improving the noise reduction effect.

As shown in Figures 4 and 5, the ends 41a, 41b of the first and second partition plate portions 41, 42 on the inlet 24 side abut against the upstream wall portion 23. As a result, as shown in Figure 6, the inlet 24 is divided into a center inlet 24c, a first side inlet 24a adjacent to the first side wall portion 22A side of the center inlet 24c in the width direction, and a second side inlet 24b adjacent to the second side wall portion 22B side of the center inlet 24c in the width direction. The dashed lines in Figure 6 indicate the ends of the partition plate portions 41, 42 on the inlet 24 side.

The widthwise dimension LC of the center inlet 24c is smaller than the widthwise dimension LS of each of the first side inlet 24a and the second side inlet 24b. Therefore, the flow area of the center inlet 24c is smaller than the flow area of each of the first side inlet 24a and the second side inlet 24b. This is a configuration for suppressing the pressure drop of the injected air from the injection nozzle 31 while enhancing the noise reduction effect.

That is, the air flowing in from the first side inlet 24a is guided to the nozzle section 30 through the first space surrounded by the main plate sections 21, the upstream wall section 23, the first partition plate section 41, and the first side wall section 22A. At this time, the first space functions as a silencer because the flow area of the air in the first space is larger than the flow area of the first side inlet 24a. On the other hand, the air flowing in from the second side inlet 24b is guided to the nozzle section 30 through the second space surrounded by the main plate sections 21, the upstream wall section 23, the second partition plate section 42, and the second side wall section 22B. At this time, the second space functions as a silencer because the flow area of the air in the second space is larger than the flow area of the second side inlet 24b. Therefore, even if the flow area of each side inlet 24a, 24b is made larger than that of the center inlet 24c, the noise generated by the flow of air can be reduced. This increases the air flow rate flowing in from the inlet 24, suppressing the pressure drop of the air injected from the nozzle 31, while enhancing the noise reduction effect. On the other hand, it was confirmed through experiments that, for example, when "LC>LS" is set and the flow area of the center inlet 24c is made larger than that of each of the side inlets 24a, 24b, noise increases.

The widthwise dimension LC (e.g., 2 mm) of the center inlet 24c may be set to less than 1/2 the widthwise dimension LS (e.g., 5.75 mm) of each side inlet 24a, 24b, and may be set to, for example, less than 1/2 and at least 1/3 of LS. In addition, in this embodiment, the dimension of the nozzle portion 30 in the direction in which each side wall portion 22A, 22B extends is smaller than the dimension of the main body portion 20, and specifically, for example, is less than 1/2 the dimension of the main body portion 20. This allows the first and second spaces of the main body portion 20 to be larger, thereby improving the noise reduction effect.

Unlike this embodiment, the configuration of Comparative Example 1 shown in FIG. 7 increases noise. The configuration of Comparative Example 1 has first and second block portions 51 and 52, each of which has a right-angled triangular prism-shaped cross section, instead of the first and second partition plate portions 41 and 42. Each block portion 51 and 52 extends from one main plate portion 21 to the other main plate portion 21. In the configuration of Comparative Example 1, the internal volume of the main body portion 20 is smaller than in this embodiment, so noise increases. Also, in the configuration of Comparative Example 1, the air injected from the injection port 31 is biased in the width direction compared to this embodiment.

As shown in FIG. 4, the tip of each partition plate 41, 42 on the injection port 31 side is located at the boundary 26 between the nozzle portion 30 and the main body portion 20 in the main plate portion 21, or on the inlet 24 side of the nozzle portion 30. In this embodiment, the tip is located on the inlet 24 side of the nozzle portion 30, specifically, on the injection port 31 side of the center of the direction in which each side wall portion 22A, 22B extends in the main body portion 20. This is a configuration for enhancing the noise reduction effect. Unlike this embodiment, in the configuration of Comparative Example 2 shown in FIG. 8, the tips of the first and second partition plate portions 61, 62 are located on the injection port 31 side of the boundary 26. In this case, it was confirmed by experiment that the air passing through the first and second spaces is directly guided to the nozzle portion 30 by each partition plate portion 41, 42, and the noise generated by the air colliding with the inner surface of the nozzle portion 30 is increased compared to this embodiment.

As shown in FIG. 4, in a plan view of the plate surface of the main plate portion 21 in the main body portion 20, the angle between the first partition plate portion 41 and the second partition plate portion 42 is set so that the first virtual line K1 extending from the first partition plate portion 41 to the injection port 31 side in the direction in which the first partition plate portion 41 extends and the second virtual line K2 extending from the second partition plate portion 42 to the injection port 31 side in the direction in which the second partition plate portion 42 extends pass through the boundary 26. In this embodiment, in a plan view of the plate surface of the main plate portion 21 in the main body portion 20, the angle between the first partition plate portion 41 and the second partition plate portion 42 is set so that the first virtual line K1 and the second virtual line K2 pass through the injection port 31. This can enhance the noise reduction effect.

Unlike this embodiment, the configuration of Comparative Example 3 shown in FIG. 9 increases noise. In the configuration of Comparative Example 3, the first virtual line K1 extending from the first partition plate portion 71 does not pass through the boundary 26 and intersects with the main body portion 20 of the first side wall portion 22A. Also, the second virtual line K2 extending from the second partition plate portion 72 does not pass through the boundary 26 and intersects with the main body portion 20 of the second side wall portion 22B. In this case, most of the air guided by each partition plate portion 71, 72 collides with each side wall portion 22A, 22B, increasing noise. Also, since most of the air guided by each partition plate portion 71, 72 collides with each side wall portion 22A, 22B, the air is not guided smoothly to the injection port 31 side, and the pressure of the injected air from the injection port 31 decreases.

According to the present embodiment described above, it is possible to provide an air injection nozzle 10 that can reduce noise while suppressing bias in the direction in which the injection port 31 extends.

<Other embodiments>
The above embodiment may be modified as follows.

- The configuration shown in FIG. 8 or FIG. 9 may be used as the air injection nozzle. Even in this case, it is possible to obtain effects similar to those of the above embodiment.

- The main plate portion is not limited to being rectangular in shape, but may be, for example, an arc-shaped portion whose side edges are convex outward in the width direction.

- The inlet 24 is not limited to a perfect circle, but may be, for example, an oval shape that is long in the width direction, or a rectangular shape.

The ends 41a, 41b of the first and second partition plate portions 41, 42 on the inlet 24 side may be spaced a predetermined distance from the upstream wall portion 23 in the direction from the inlet 24 side toward the injection port 31 side (specifically, in the direction perpendicular to the width direction and height direction). This predetermined distance may be, for example, a distance in the range of 1 mm to 2 mm. In this case, the first side inlet is a flow path formed by the upstream wall portion 23, the end 41a of the first partition plate portion 41, and each main plate portion 21, and the second side inlet is a flow path formed by the upstream wall portion 23, the end 42a of the second partition plate portion 42, and each main plate portion 21. In addition, the center inlet is a flow path formed by the ends of the first and second partition plate portions 41, 42, and each main plate portion 21. Even in this case, it is sufficient that the flow path area of each of the first and second side inlets is set to be larger than the flow path area of the center inlet.

- In addition to the first and second partition plate portions 41, 42, one or more additional partition plate portions may be provided in the air injection nozzle 10 to divide the air flowing in from the inlet 24 and guide it to the injection port 31. In this case, the additional partition plate portion may be plate-shaped and provided to extend from the inlet side 24 toward the injection port 31.

10...air injection nozzle, 21...main plate portion, 22A, 22B...first and second side wall portions, 23...upstream wall portion, 24...inlet port, 30...nozzle portion, 31...injection port, 41, 42...first and second partition plate portions.

Claims (7)

In an air injection nozzle (10) for blowing off dust by injecting air from an inlet (24) through an injection port (31),
A pair of main plate portions (21) arranged with their plate surfaces facing each other;
A side wall portion (22A, 22B) connecting side edges of each of the main plate portions;
an upstream wall portion (23) provided to close one of a pair of openings formed by the main plate portions and the side wall portions;
Equipped with
Of a pair of openings formed by the main plate portions and the side wall portions, the other opening is the injection port having an elongated shape extending in a direction in which the side wall portions face each other,
The inlet is formed in a middle portion of the upstream wall portion in a direction in which the side wall portions face each other,
a plurality of partition plate portions (41, 42) provided in a space surrounded by the main plate portions, the side wall portions, and the upstream wall portion, extending from the inlet side toward the outlet side, and dividing the air flowing in from the inlet and directing it to the outlet,
As the plurality of partition plate portions,
a first partition plate portion (41) extending from the inlet side toward one side with respect to a center of the injection port in a direction in which the side wall portions face each other;
a second partition plate portion (42) extending from the inlet side toward the other side with respect to the center of the injection port in the direction in which the side wall portions face each other;
Equipped with
The first partition plate portion and the second partition plate portion are provided with their plate surfaces facing the side wall portion. The main plate portions and the side wall portions have nozzle portions (30) at their ejection port side, and the distance between the main plate portions decreases toward the ejection port side.
2. The air injection nozzle according to claim 1, wherein a tip end of the first partition plate portion and the second partition plate portion on the side of the injection port is located at a boundary between the main plate portion and the nozzle portion, or on the inlet side of the nozzle portion. The air injection nozzle according to claim 1 or 2, wherein the flow area of the first side inlet (24a) formed by the upstream wall portion, the inlet side end (41a) of the first partition plate portion, and each of the main plate portions, and the flow area of the second side inlet (24b) formed by the upstream wall portion, the inlet side end (41b) of the second partition plate portion, and each of the main plate portions, are larger than the flow area of the center inlet (24c) formed by the inlet side end of the first partition plate portion, the inlet side end of the second partition plate portion, and each of the main plate portions. The air injection nozzle according to claim 3, wherein the inlet is divided into the center inlet, the first side inlet adjacent to one side of the center inlet in the direction in which the side walls face each other, and the second side inlet adjacent to the other side of the center inlet in the direction in which the side walls face each other by the inlet-side ends of the first partition plate portion and the second partition plate portion. The air injection nozzle according to claim 1 or 2, wherein the inlet side end portions (41a, 41b) of the first partition plate portion and the second partition plate portion have a tapered shape in which the plate thickness becomes thinner toward the inlet side. The air injection nozzle according to claim 2, wherein an angle between the first partition plate portion and the second partition plate portion is set so that, in a plan view of the plate surface of the main plate portion, a first virtual line (K1) extending from the first partition plate portion toward the nozzle in the direction in which the first partition plate portion extends, and a second virtual line (K2) extending from the second partition plate portion toward the nozzle in the direction in which the second partition plate portion extends, pass through the boundary between the main plate portion and the nozzle portion. The air injection nozzle according to claim 2, wherein the angle (θ) between the main plate portions in the nozzle portion is set to an angle in the range of 50° to 70°.

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