WO2013042929A2

WO2013042929A2 - Lip cleaner for air knife having improved ventilation

Info

Publication number: WO2013042929A2
Application number: PCT/KR2012/007483
Authority: WO
Inventors: 황운봉; 정완균; 조현석; 김동섭; 이상민; 이창우
Original assignee: 포항공과대학교 산학협력단
Priority date: 2011-09-23
Filing date: 2012-09-19
Publication date: 2013-03-28
Also published as: KR101290319B1; WO2013042929A3; KR20130032677A

Abstract

The present invention provides a lip cleaner for an air knife in which a first discharge port, a second discharge port, and a third discharge port are arranged side by side. The lip cleaner for an air knife comprises: an operation main body, which is movably installed along the lengthwise direction of the second discharge port; a center cleaner portion which is connected to an end portion of the operation main body; an upper cleaner portion which is connected to an end portion of the center cleaner portion by means of a first connection portion and is inserted into the first discharge port; and a lower cleaner portion which is connected to the end portion of the center cleaner portion by means of a second connection portion and is inserted into the third discharge port, wherein the widths of the upper cleaner portion and the lower cleaner portion are formed to be larger than the width of the center cleaner portion.

Description

Breathable Lip Cleaner for Air Knife

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lip cleaner for an air knife, and more particularly, to a lip cleaner for removing zinc chips deposited on a lip surface of an air knife in a galvanizing process of steel sheet.

Among the cold rolled steel sheets, the zinc plated steel sheet coated with zinc has excellent corrosion resistance and excellent appearance. The galvanizing process of the steel sheet consists of a hot-dip plating process of passing the steel sheet through a plating bath in which the hot dip zinc is stored. Molten zinc is fused to the surface of the steel plate passed through the plating bath, the air knife installed on the upper portion of the plating bath is sprayed with high-pressure air to both surfaces of the steel sheet to adjust the amount of plating by shaving off a portion of the fused zinc.

However, when high-pressure air is injected through the discharge port formed between the upper lip and the lower lip of the air knife, the molten zinc grows on the inclined surface of the lip due to the vortex phenomenon, thereby preventing the discharge port. In this case, plating defects occur, such as streaks on the surface of the steel sheet.

Therefore, the lip cleaner is installed at the discharge port of the air knife, and moves along the longitudinal direction of the discharge port in contact with the surfaces of the upper lip and the lower lip to scrape off the zinc chips on the lip surface. In this case, the larger the width of the lip cleaner, the more effective the air knife can be cleaned. However, the smaller the width of the lip cleaner, the smaller the width of the lip cleaner does not prevent the flow of air, but eccentricity occurs when removing the stuck zinc chips. The center of the cleaner may rotate.

An object of the present invention is to provide a lip cleaner for an air knife which can increase the plating quality of a steel sheet by increasing the width of the lip cleaner to effectively remove zinc chips stuck to the air knife and at the same time not disturbing the flow of air.

According to one embodiment of the present invention, in the lip cleaner for air knife having the first discharge port, the second discharge port and the third discharge port arranged side by side, the operation main body is installed to be movable along the longitudinal direction of the second discharge port, A central cleaner portion connected to an end of the main body, an upper cleaner portion connected to an end portion of the central cleaner portion by a first connection portion, and fitted to the first discharge port, and connected to an end portion of the central cleaner portion by a second connection portion, And a lower cleaner portion to be fitted, wherein the width of the upper cleaner portion and the lower cleaner portion is larger than that of the central cleaner portion.

The first connection part may be bent downward from the center of the end portion of the upper cleaner part, and an air discharge space may be provided on left and right sides of the first connection part. The width of the first connection portion may be equal to or less than the end width of the central cleaner portion, and the width of the upper cleaner portion may be greater than the maximum width of the central cleaner portion.

The second connection part may be bent upward from the center of the end portion of the lower cleaner part, and an air discharge space may be provided on left and right sides of the second connection part. The width of the second connection portion may be less than or equal to the end width of the central cleaner portion, and the width of the lower cleaner portion may be greater than the maximum width of the central cleaner portion.

The central cleaner portion may be formed in a trapezoidal shape, and the upper cleaner portion and the lower cleaner portion may have a rectangular shape. Each of the central cleaner portion, the upper cleaner portion, and the lower cleaner portion may form an upper blade bent upward on one side and a lower blade bent downward on the other side.

On the other hand, the central cleaner portion, the first connection portion and the second connection portion may be provided in pairs. The pair of central cleaners may be spaced apart from each other along the width direction of the operation body.

An air discharge space may be provided between the pair of first connections, and the upper cleaner portion may form a central opening that expands the air discharge space. The width of the central opening may be equal to the distance between the pair of first connecting portions, and the height of the central opening may be smaller than the height of the upper cleaner portion.

An air discharge space may be provided between the pair of second connecting portions, and the lower cleaner portion may form a central opening that expands the air discharge space. The width of the central opening may be equal to the distance between the pair of second connecting portions, and the height of the central opening may be smaller than the height of the lower cleaner portion.

Each of the central cleaner portion, the upper cleaner portion, and the lower cleaner portion may have a rectangular shape, may form an upper blade bent upward on one side, and a lower blade bent downward on the other side.

On the other hand, the first connection portion and the second connection portion is provided in a pair, the upper cleaner portion and the lower cleaner portion may form a pair of wedge-shaped protrusions. Air discharge spaces may be provided on the left and right sides of each of the pair of first connectors and on the left and right sides of each of the pair of second connectors.

In the lip cleaner of the embodiments, the upper and lower cleaner portions are formed to have a larger width than the central cleaner portion, so that the air knife can be effectively cleaned, and the air discharge space is positioned between the pair of first connectors and the pair of second connectors. Therefore, it is possible to smoothly control the amount of galvanized steel without disturbing the flow of air.

1 is a perspective view of a lip cleaner for an air knife according to a first embodiment of the present invention.

FIG. 2 is a side view of the lip cleaner shown in FIG. 1. FIG.

3 is a front view of the air knife equipped with the lip cleaner shown in FIG. 1.

4 is an enlarged view of a central cleaner part of the lip cleaner shown in FIG. 1.

5 is an enlarged view of the upper cleaner part of the lip cleaner shown in FIG. 1.

FIG. 6 is an enlarged view of a lower cleaner part of the lip cleaner shown in FIG. 1.

7 is a perspective view of a lip cleaner for an air knife according to a second embodiment of the present invention.

FIG. 8 is an enlarged view of a central cleaner part of the lip cleaner shown in FIG. 7.

FIG. 9 is an enlarged view of the upper cleaner part of the lip cleaner shown in FIG. 7.

FIG. 10 is an enlarged view of a lower cleaner part of the lip cleaner shown in FIG. 7.

11 is a perspective view of a lip cleaner for an air knife according to a third embodiment of the present invention.

FIG. 12 is an enlarged view of a central cleaner part of the lip cleaner shown in FIG. 11.

FIG. 13 is an enlarged view of the upper cleaner part of the lip cleaner illustrated in FIG. 11.

FIG. 14 is an enlarged view of a lower cleaner part of the lip cleaner shown in FIG. 11.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a perspective view of a lip cleaner for an air knife according to a first embodiment of the present invention, FIG. 2 is a side view of the lip cleaner shown in FIG. 1, and FIG. 3 is an air knife equipped with the lip cleaner shown in FIG. 1. Front view. The air knife is shown in dashed lines in FIG. 2.

1 to 3, the air cleaner lip cleaner 100 is a lip cleaner for the air knife 50 in which three

discharge ports

61, 62, and 63 are disposed side by side.

The air knife 50 is composed of an upper lip 51, a first intermediate lip 52, a second intermediate lip 53, and a lower lip 54 positioned side by side at a distance from each other. The first discharge port 61 is positioned between the upper lip 51 and the first intermediate lip 52, and the second discharge port 62 is positioned between the first intermediate lip 52 and the second intermediate lip 53. . The third discharge port 63 is positioned between the second intermediate lip 53 and the lower lip 54.

The first to

third discharge ports

61, 62, and 63 face a steel sheet (not shown) in which molten zinc is fused to the surface, and blows a portion of the fused zinc by spraying high pressure air onto the surface of the steel sheet. Adjust the plating amount. At this time, the flow rate and pressure of the air discharged from the second discharge port 62 may be greater than the flow rate and pressure of the air discharged from the first and

third discharge ports

61 and 63.

The lip cleaner 100 is mounted to the discharge ports 61 to 63 of the air knife 50, and reciprocates along the longitudinal direction (the horizontal direction in FIG. 3) of the discharge holes 61 to 63 during the operation of the air knife 50. It moves and scrapes off the zinc chip on the surface of the air knife 50.

The lip cleaner 100 includes an operation body 11 installed to be movable along a length direction of the second discharge port 62, a central cleaner 20 connected to an end of the operation body 11, and a central cleaner part. The upper cleaner part 30 located in the upper side of the 20, and the lower cleaner part 40 located in the lower side of the center cleaner part 20 are included. The upper cleaner part 30 and the lower cleaner part 40 are fixed to the central cleaner part 20 integrally.

The operation body 11 and the central cleaner portion 20 are fitted to the second discharge port 62 of the air knife 50. The operating body 11 is coupled to a driving cylinder (not shown) via a driving wire (not shown) or the like and installed to move left and right along the length direction of the second discharge port 62. The operating body 11 may be provided with a pair of through holes 12 for coupling with a driving wire or the like.

4 is an enlarged view of a central cleaner part of the lip cleaner shown in FIG. 1, FIG. 5 is an enlarged view of an upper cleaner part of the lip cleaner shown in FIG. 1, and FIG. 6 is a lower cleaner part of the lip cleaner shown in FIG. 1. It is an enlarged view.

1 to 6, the central cleaner unit 20 may be integrally formed with the operating body 11 and may have a smaller width than the operating body 11. For example, the central cleaner 20 may be formed in a trapezoidal shape in which the width is gradually narrowed away from the operation body 11.

One side of the central cleaner portion 20 is formed with the upper blade 21 bent upward, the lower blade 22 is bent downward on the other side. The upper blade 21 contacts the lower surface of the first intermediate lip 52 to remove zinc chips deposited thereon. The lower blade 22 contacts the upper surface of the second intermediate lip 53 to remove zinc chips deposited thereon.

The upper blade 21 and the lower blade 22 may be formed of the same length or different lengths. In FIG. 4, an example in which the upper blade 21 and the lower blade 22 are formed in the same length is illustrated.

The upper cleaner part 30 is fitted to the first discharge port 61 of the air knife 50. The upper cleaner part 30 forms the first connection part 35 bent downward toward the central cleaner part 20, and the first connection part 35 is fixed to the end of the central cleaner part 20 by welding or the like. do. As a result, the upper cleaner portion 30 moves together with the central cleaner portion 20 when the operation body 11 moves.

An end portion of the first discharge port 61 may be installed to be inclined from the top to the bottom along the spraying direction of air (see FIG. 2). The upper cleaner part 30 may be inclined at a predetermined inclination angle with respect to the central cleaner part 20 in accordance with the inclination angle of the first discharge port 61. The upper cleaner part 30 may be formed in a rectangle having a predetermined width.

One side of the upper cleaner portion 30 is formed with the upper blade 31 bent upward, the lower blade 32 is bent downward on the other side. The upper blade 31 is in contact with the lower surface of the upper lip 51 to remove zinc chips thereon, and the lower blade 32 is in contact with the upper surface of the first intermediate lip 52 and is deposited there. Remove it.

The upper blade 31 and the lower blade 32 may be formed of the same length or different lengths. In FIG. 5, an example in which the upper blade 31 is formed to have a length smaller than that of the lower blade 32 is illustrated.

The upper cleaner part 30 is formed to have a larger width than the central cleaner part 20. Specifically, the width w1 (see FIG. 5) of the upper cleaner portion 30 is larger than the maximum width w2 (see FIG. 4) of the central cleaner portion in contact with the actuating main body 11. In this case, the width of the first connection part 35 is formed to be equal to or smaller than the end width of the central cleaner part 20. In FIG. 1, an example in which the width of the first connection part 35 is the same as the end width of the central cleaner part 20 is illustrated.

Accordingly, the upper cleaner portion 30 enlarges the width thereof to effectively remove the zinc chips stuck to the air knife 50 and at the same time provides the air discharge spaces 15 on the left and right sides of the first connection portion 35 to provide the steel sheet. Does not impede the flow of air towards it. That is, the upper cleaner portion 30 is made of a structure in which the zinc chip removal effect and the air permeability are improved at the same time.

The lower cleaner part 40 is fitted into the third discharge port 63 of the air knife 50. The lower cleaner part 40 forms the second connection part 45 bent upward toward the center cleaner part 20, and the second connection part 45 is fixed to the end of the center cleaner part 20 by welding or the like. . As a result, the lower cleaner portion 40 moves together with the central cleaner portion 20 when the operation body 11 moves.

An end portion of the third discharge port 63 may be installed to be inclined from the bottom up in the spraying direction of air (see FIG. 2). The lower cleaner part 40 may be inclined at a predetermined inclination angle with respect to the central cleaner part 20 in accordance with the inclination angle of the third discharge port 63. The lower cleaner part 40 may be formed in a rectangle having a predetermined width.

One side of the lower cleaner portion 40 is formed with the upper blade 41 bent upward, and the lower blade 42 is bent downward on the other side. The upper blade 41 contacts the lower surface of the second intermediate lip 53 to remove zinc chips thereon, and the lower blade 42 contacts the upper surface of the lower lip 54 and the zinc chips deposited thereon. Remove it.

The upper blade 41 and the lower blade 42 may be formed of the same length or different lengths. In FIG. 6, an example in which the upper blade 41 is formed to have a greater length than the lower blade 42 is illustrated.

The lower cleaner part 40 is formed to have a larger width than the central cleaner part 20. Specifically, the width w3 (see FIG. 6) of the lower cleaner portion 40 is larger than the maximum width w2 (see FIG. 4) of the central cleaner portion 20 in contact with the actuating main body 11. At this time, the width of the second connection portion 45 is formed equal to or smaller than the end width of the central cleaner portion 20. In FIG. 1, a case in which the width of the second connection part 45 is equal to the end width of the central cleaner part 20 is illustrated as an example.

Therefore, the lower cleaner portion 40 enlarges the width thereof to effectively remove the zinc chips stuck to the air knife 50 and at the same time provides the air discharge spaces 15 on the left and right sides of the second connecting portion 45 to provide the steel sheet. Does not impede the flow of air towards it. That is, the lower cleaner part 40 has a structure in which the zinc chip removing effect and the air permeability are improved at the same time as the upper cleaner part 30.

In the lip cleaner 100 of the first embodiment, the upper cleaner part 30 and the lower cleaner part 40 are formed to have a larger width than the central cleaner part 20 to effectively clean the air knife 50. In addition, since the air discharge space 15 is positioned on the left and right sides of the first connection part 35 and the second connection part 45, the air flow is not disturbed. That is, the air discharged from the first to third discharge ports 61 to 63 is discharged to the steel sheet through the air discharge spaces 15 provided on the left and right sides of the first and

second connection parts

35 and 45 to reduce the amount of zinc plating. Used to adjust.

If it is assumed that the first and

second connection portions

35 and 45 are formed to have the same width as the upper cleaner portion 30 and the lower cleaner portion 40, the lip cleaner prevents the air from being discharged. As the larger the lip cleaner is passed through the galvanized amount can not be adjusted along the portion may cause a stripe failure in the steel sheet.

However, the lip cleaner 100 of the first embodiment discharges the air of the discharge holes 61 to 63 toward the steel sheet through the air discharge spaces 15 provided on the left and right sides of the first and

second connection parts

35 and 45. It is possible to prevent generation of streaks in the steel sheet by the lip cleaner 100. Since the lip cleaner 100 does not prevent the discharge of air but merely reduces the discharge of air, the lip cleaner 100 may be used for the steel sheet by the lip cleaner 100 even when the widths of the upper and lower

cleaner parts

30 and 40 are enlarged. Striping defects do not occur.

7 is a perspective view of a lip cleaner for an air knife according to a second exemplary embodiment of the present invention, and FIGS. 8 to 10 are enlarged views of a central cleaner part, an upper cleaner part, and a lower cleaner part, respectively, of the lip cleaner shown in FIG. 7. .

7 to 10, the lip cleaner 200 of the second embodiment is connected to the end of the central cleaner unit 20 by a pair of central cleaner units 20 and a pair of first connection units 35. The upper cleaner unit 30 is connected, and the lower cleaner unit 40 is connected to the end of the central cleaner unit 20 by a pair of second connection units 45. An air discharge space 15 is formed between the pair of first connecting portions 35 and the pair of second connecting portions 45.

The pair of central cleaners 20 are spaced apart from each other along the width direction of the operation main body 11. The pair of central cleaners 20 may be formed in a rectangle having a predetermined width and may have the same width as each other. Each of the pair of central cleaners 20 may form the upper blade 21 bent upward on one side and the lower blade 22 bent downward on the other side.

The upper cleaner portion 30 forms a pair of first connecting portions 35 bent downward toward the central cleaner portion 20, and the first connecting portions 35 are welded to the end of the central cleaner portion 20. Method is fixed. In this case, the width of the first connection part 35 may be formed to be equal to or smaller than the end width of the central cleaner part 20. In FIG. 7, the width of the first connection part 35 is equal to the end width of the central cleaner part 20.

The upper cleaner unit 30 may form a central opening 36 that expands the air discharge space 15 so as to smoothly discharge the air. The width w4 of the central opening 36 (see FIG. 9) is equal to the distance between the pair of first connecting portions 35, and its height h1 (see FIG. 9) is equal to that of the upper cleaner portion 30. It is formed smaller than the height h2 (see FIG. 9). As a result, the upper cleaner part 30 is formed in an approximately Di '(') shape.

The upper cleaner part 30 forms the upper blade 31 bent upward on one side and the lower blade 32 bent downward on the other side. In addition, the upper cleaner portion 30 may form the upper blade 31 bent upward on one side of the central opening 36 and the lower blade 32 bent downward on the other side of the central opening 36. have.

The lower cleaner part 40 forms a pair of second connection parts 45 bent upward toward the central cleaner part 20, and the second connection part 45 is welded to the end of the central cleaner part 20. Is fixed. In this case, the width of the second connection part 45 may be formed to be equal to or smaller than the end width of the central cleaner part 20. In FIG. 7, the width of the second connection part 45 is equal to the width of the end portion of the central cleaner part 20.

The lower cleaner portion 40 may form a central opening 46 that expands the air discharge space 15 so as to smoothly discharge the air. The width w5 of the central opening 46 (see FIG. 10) is equal to the distance between the pair of second connecting portions 45, and its height h3 (see FIG. 10) is equal to that of the lower cleaner portion 40. It is formed smaller than the height h4 (see FIG. 10). As a result, the lower cleaner portion 40 is formed in an approximately Di '(') shape.

The lower cleaner portion 40 forms the upper blade 41 bent upward on one side and the lower blade 42 bent downward on the other side. In addition, the lower cleaner portion 40 may form the upper blade 41 bent upward on one side of the central opening 46 and the lower blade 42 bent downward on the other side of the central opening 46. have.

In the lip cleaner 200 of the second embodiment, since the upper and lower

cleaner parts

30 and 40 are formed to have a larger width than the central cleaner part 20, the air knife 50 can be effectively cleaned, and the pair of first Since the air discharge space 15 is positioned between the connecting portion 35 and the pair of second connecting portions 45, it is possible to smoothly adjust the galvanized amount of the steel sheet without disturbing the flow of air.

11 is a perspective view of a lip cleaner for an air knife according to a third exemplary embodiment of the present invention, and FIGS. 12 to 14 are enlarged views of a central cleaner part, an upper cleaner part, and a lower cleaner part, respectively, of the lip cleaner shown in FIG. 11. .

11 to 14, the lip cleaner 300 of the third embodiment is an upper portion connected to an end portion of the central cleaner portion 20 by a central cleaner portion 20 and a pair of first connecting portions 35. The cleaner part 30 and the lower cleaner part 40 connected to the end part of the center cleaner part 20 by a pair of 2nd connection part 45 are included.

The upper cleaner part 30 and the lower cleaner part 40 include a pair of wedge-shaped

protrusions

37 and 47, and each of the left and right sides of the pair of first connection parts 35 and a pair of second connection parts ( 45) Air discharge spaces 15 are provided on the left and right sides of each.

The central cleaner 20 may have the same width as the operation body 11 and may be formed in a rectangle having a predetermined width. One side of the central cleaner portion 20 is formed with the upper blade 21 bent upward, the lower blade 22 is bent downward on the other side.

The upper cleaner portion 30 forms a pair of first connecting portions 35 bent downward toward the central cleaner portion 20, and the first connecting portions 35 are welded to the end of the central cleaner portion 20. Method is fixed. The pair of first connectors 35 are spaced apart from each other, and the air discharge spaces 15 are formed at left and right sides of each of the pair of first connectors 35.

The upper cleaner part 30 is formed to have a larger width than the central cleaner part 20, and unlike the above-described embodiments, the upper cleaner part 30 is not formed flat and has a three-dimensional shape having a pair of wedge-shaped protrusions 37. One side of the upper cleaner portion 30 is formed with the upper blade 31 bent upward, the lower blade 32 is bent downward on the other side.

The lower cleaner portion 40 forms a pair of second connecting portions 45 bent upward toward the central cleaner portion 20, and the second connecting portions 45 are welded to the end of the central cleaner portion 20. Is fixed. The pair of second connectors 45 are spaced apart from each other, and the air discharge spaces 15 are formed at left and right sides of each of the pair of second connectors 45.

The lower cleaner part 40 is formed to have a larger width than the central cleaner part 20, and unlike the above-described embodiments, the lower cleaner part 40 is not formed flat and has a three-dimensional shape having a pair of wedge-shaped protrusions 47. One side of the lower cleaner portion 40 is formed with the upper blade 41 bent upward, and the lower blade 42 is bent downward on the other side.

In the lip cleaner 300 of the third embodiment, since the upper and lower

cleaner parts

30 and 40 are formed to have a larger width than the central cleaner part 20, the air knife 50 can be effectively cleaned, and the pair of first Since the air discharge space 15 is positioned on the left and right sides of each of the connection part 35 and the pair of second connection parts 45, it is possible to smoothly adjust the galvanization amount of the steel sheet without disturbing the flow of air.

In addition, the lip cleaner 300 of the third embodiment may prevent the lip cleaner 300 from being lifted when an eccentricity is generated, and the upper and lower

cleaner parts

30 and 40 may be lifted even when the lip cleaner 300 is lifted. A pair of wedge-shaped

protrusions

37 and 47 formed therein may scrape the surface of the air knife 50 to remove zinc chips.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

Claims

In the lip cleaner for an air knife in which the first discharge port, the second discharge port, and the third discharge port are arranged side by side,

An operation body installed to be movable along the length direction of the second discharge port;

A central cleaner part connected to an end of the operation body;

An upper cleaner part connected to an end of the central cleaner part by a first connection part and fitted to the first discharge port; And

A lower cleaner part connected to an end of the central cleaner part by a second connection part and fitted to the third discharge port;

The width cleaner of the upper cleaner portion and the lower cleaner portion is larger than the width of the central cleaner portion.
The method of claim 1,

The first connector is formed by bending downward from the center of the end of the upper cleaner portion, the air cleaner lip cleaner is provided with an air discharge space on the left and right sides of the first connection portion.
The method of claim 2,

The width of the first connecting portion is less than or equal to the width of the end portion of the central cleaner portion, the width of the upper cleaner portion is larger than the maximum width of the central cleaner portion.
The method of claim 2,

The second connector is formed by bending upward from the center of the end of the lower cleaner portion, the air cleaner lip cleaner is provided on the left and right sides of the second connection portion.
The method of claim 4, wherein

The width of the second connecting portion is less than or equal to the end width of the central cleaner portion, the width of the lower cleaner portion is larger than the maximum width of the central cleaner portion lip cleaner.
The method according to any one of claims 2 to 5,

The central cleaner portion is formed in a trapezoidal shape, the upper cleaner portion and the lower cleaner portion are formed in a rectangular shape,

And the center cleaner portion, the upper cleaner portion, and the lower cleaner portion each form an upper blade bent upward on one side and a lower blade bent downward on the other side.
The method of claim 1,

Lip cleaner for an air knife provided with the pair of the central cleaner, the first connection portion and the second connection portion.
The method of claim 7, wherein

And the pair of central cleaners are spaced apart from each other along the width direction of the operating body.
The method of claim 7, wherein

An air discharge space is provided between the pair of first connecting portions, and the upper cleaner portion defines a central opening for expanding the air discharge space.
The method of claim 9,

And the width of the central opening is equal to the distance between the pair of first connecting portions, and the height of the central opening is smaller than the height of the upper cleaner portion.
The method of claim 7, wherein

An air discharge space is provided between the pair of second connecting portions, and the lower cleaner portion defines a central opening that extends the air discharge space.
The method of claim 11,

And the width of the central opening is equal to the distance between the pair of second connecting portions, and the height of the central opening is smaller than the height of the lower cleaner portion.
The method according to any one of claims 7 to 12,

The central cleaner portion, the upper cleaner portion, and the lower cleaner portion are each formed in a rectangular shape, and form an upper blade bent upward on one side and a lower blade bent downward on the other side.
The method of claim 1,

The first connection portion and the second connection portion is provided in a pair, the upper cleaner portion and the lower cleaner portion is a lip cleaner for an air knife to form a pair of wedge-shaped projections.
The method of claim 14,

Lip cleaner for an air knife provided with an air discharge space on the left and right side of each of the pair of first connecting portion and the left and right side of each of the pair of second connecting portion.
The method according to claim 14 or 15,

The central cleaner portion, the upper cleaner portion, and the lower cleaner portion are each formed in a rectangular shape, forming an upper blade bent upward on one side, and a lower blade bent downward on the other side.