AIR KNIFE SYSTEM HAVING ANGLE ADJUSTING APPARATUS

Abstract

 Proposed is an air knife system having an angle adjusting apparatus. When a screw shaft is rotated, a moving body is moved in a vertical direction, and an angle adjusting lever receives a moving force of the moving body through a shaft member, a rotating body, and a movable rail, so that the angle adjusting lever is rotated with respect to a pipe center. In this process, the rotating body is moved together with the moving body and is rotated around the shaft member, and the movable rail is rotated together with the rotating body and is spaced apart or is approached to the pipe center. Therefore, the angle adjusting lever rotates a first gas supply pipe, and changes a vertical angle of an air knife with respect to a plated steel sheet.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to Korean Patent Application No. 10-2022-0090546, filed July 21, 2022, the entire contents of which are incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] An embodiment of the present disclosure relates to an air knife system including an air knife and an apparatus adjusting a vertical angle of the air knife.

Description of the Related Art

[0003] Generally, an air knife may jet gas at a high pressure so as to control the plating amount (plating thickness) of a zinc plated steel sheet, and an angle of the air knife may be adjusted in a vertical direction according to working conditions and working processes.

[0004] In a conventional technology, there is a structural problem that the angle of the air knife cannot be smoothly adjusted since a mounting position of the air knife is narrow and interference between the air knife and surrounding equipment occurs. In addition, a vertical angle of the air knife cannot be accurately measured during the working processes, so that production efficiency may be reduced.

Document of Related Art

[0005] As related patent documents, KR 20-1992-0012105 U (1992.07.25), JP 2001-131724 A (2001.05.15), KR 20-0382147 Y1 (2005.04.18), KR 10-2013-0044970 A (2013.05.03), and KR 10-1866313 B1 (2018.06.14) may be referred to.

SUMMARY OF THE INVENTION

[0006] Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and an objective of an embodiment of the present disclosure is to smoothly adjust a vertical angle of an air knife. In addition, another objective of an embodiment of the present disclosure is to accurately measure an angle of the air knife.

[0007] The technical problems to be solved by the present disclosure are not limited to the above-mentioned problems and other problems which are not mentioned will be clearly understood by those skilled in the art from the following description.

[0008] According to an embodiment of the present disclosure, there is provided an air knife system including: an air knife jetting gas to a plated steel sheet; a first gas supply pipe and a second gas supply pipe which respectively extend along left and right directions from corresponding positions of both side surfaces of the air knife and which respectively protrude to left and right sides of the air knife; a body mounted above the air knife and provided with a first bracket and a second bracket which respectively support the first gas supply pipe and the second gas supply pipe such that the first gas supply pipe and the second gas supply pipe are capable of being rotated around a pipe center; and an angle adjusting apparatus configured to adjust a vertical angle of the air knife with respect to the plated steel sheet by rotating the first gas supply pipe so that the air knife is rotated around the pipe center, wherein the angle adjusting apparatus may include: a fixing body provided on the first bracket, the fixing body being positioned at a front side or a rear side of the first gas supply pipe; a screw shaft provided at the fixing body such that the screw shaft is capable of being rotated around an axis of a vertical direction, the screw shaft being configured to be rotated by a shaft driving unit; a moving body that is screw coupled to the screw shaft, the moving body being capable of moving in the vertical direction according to a rotation direction of the screw shaft; an angle adjusting lever provided with a first end portion coupled to the first gas supply pipe, the angle adjusting lever being provided with a second end portion connected to the moving body through a power transmission unit, wherein the power transmission unit may be configured to rotate the angle adjusting lever by transmitting a moving force of the moving body to the angle adjusting lever.

[0009] The power transmission unit may include: a shaft member provided on the moving body such that the shaft member is capable of being rotated around an axis of the left and right directions; a rotating body provided on the shaft member and configured to be rotated together with the shaft member; and a slider provided on the rotating body such that the slider is capable of being moved along a radial direction of the pipe center, the slider being coupled to the second end portion of the angle adjusting lever.

[0010] The air knife system may further include a first angle measurement apparatus. The first angle measurement apparatus may include: a first gear member provided on the angle adjusting lever and provided with a gear teeth of a pinion provided along an outer circumference with respect to the pipe center, the first gear member having the gear teeth disposed at the front side or the rear side of the first gas supply pipe; a second gear member that extends in the vertical direction such that an upper end portion of the second gear member is positioned at a side of the body, the second gear member having a lower end portion provided with a gear teeth of a rack engaged with the gear teeth of the first gear member; a guide module connected to the fixing body and configured to support the second gear member such that the second gear member is capable of being moved in the vertical direction; a scale body provided on the body such that the scale body is positioned at a side of an upper end portion of the second gear member, the scale body being provided with a scale for indicating a rotation angle of the air knife; and a scale indicator provided on the upper end portion of the second gear member, the scale indicator being configured to be moved in the vertical direction according to a rotation of the angle adjusting lever, thereby indicating the scale.

[0011] The guide module may include: an auxiliary body connected to the fixing body; a supporting member supporting the second gear member such that the second gear member is capable of being moved in the vertical direction; and at least one elastic member providing elastic force toward the first gear member to the supporting member from between the auxiliary body and the supporting member.

[0012] The air knife system according to an embodiment of the present disclosure may further include a second angle measurement apparatus. The second angle measurement apparatus may include: a measurement jig provided on the second gas supply pipe and provided with a first gear teeth along an outer circumference with respect to the pipe center; a measurement module provided with a rotation element having an outer circumference provided with a second gear teeth that is engaged with the first gear teeth, the measurement module being configured to detect a rotation amount of the rotation element; a module holder having the measurement module, the module holder being provided such that the module holder is capable of being rotated around a hinge shaft that is parallel to the pipe center, and the module holder being configured to space the rotation element apart from or approach the measurement jig according to a rotation direction; a mounting block provided on the second bracket, the mounting block having the hinge shaft and being disposed such that the module holder is positioned between the mounting block and the measurement jig; and at least one elastic member providing elastic force toward the measurement jig to the module holder from between the module holder and the mounting block.

[0013] The technical solutions will be more specifically and clearly described with reference to the embodiments to be described below and the drawings. In addition to the above-mentioned technical solutions, various technical solutions will be additionally provided.

[0014] According to an embodiment of the present disclosure, the angle of the air knife may be smoothly adjusted in a vertical direction. In addition, a rotation angle of the air knife may be accurately measured.

[0015] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects which are not mentioned above may be clearly understood by those skilled in the art from the present specification and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objectives, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front view illustrating an air knife system according to an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B in FIG. 2;

FIGS. 4 and 5 are conceptual views illustrating an operation of an angle adjusting apparatus in the air knife system according to an embodiment of the present disclosure;

FIG. 6 is a cross-sectional view taken along line C-C in FIG. 1; and

FIG. 7 is a cross-sectional view taken along line D-D in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0018] An air knife system according to an embodiment of the present disclosure is illustrated in FIGS. 1 to 7. The air knife system according to an embodiment of the present disclosure may include an angle adjusting apparatus 110, a first angle measurement apparatus 120, and a second angle measurement apparatus 130. FIG. 1 illustrates an entire configuration of the air knife system according to an embodiment of the present disclosure. FIGS. 2 and 3 mainly illustrate a configuration of the angle adjusting apparatus 110. FIGS. 4 and 5 conceptually illustrate an operation of the angle adjusting apparatus 110 on the basis of FIG. 2. FIG. 6 mainly illustrates the first angle measurement apparatus 120, and FIG. 7 mainly illustrates the second angle measurement apparatus 130.

[0019] Referring to FIG. 1, the air knife system according to an embodiment of the present disclosure may include: an air knife 10 jetting gas (for example, air) to a plated steel sheet (not illustrated); a first gas supply pipe 15A and a second gas supply pipe 15B which respectively extend along left and right directions from corresponding positions of both side surfaces of the air knife 10 and which respectively protrude to left and right sides of the air knife 10; a body 20 mounted above the air knife 10 and provided with a first bracket 21A and a second bracket 21B which respectively support the first gas supply pipe 15A and the second gas supply pipe 15B such that the first gas supply pipe 15A and the second gas supply pipe 15B are capable of being rotated around a pipe center 15c; and the angle adjusting apparatus 110 configured to adjust a vertical angle (that is, a gas jetting angle) of the air knife 10 with respect to the plated steel sheet by rotating the first gas supply pipe 15A so that the air knife 10 is rotated around the pipe center 15c.

[0020] In a hot-dip plating process, the air knife 10 may be positioned at a rear end of a plating bath (not illustrated). When a steel sheet (not illustrated) is deposited in molten metal (for example, zinc (Zn) and so on) in the plating bath, the steel sheet may become the plated steel sheet on which the molten metal is attached to a surface thereof. The air knife 10 may adjust the amount of molten metal (the plating amount) attached to the plated steel sheet by jetting the gas at a high pressure to the plated steel sheet that has passed through the plating bath.

[0021] The first gas supply pipe 15A and the second gas supply pipe 15B may have rectilinear shapes, and may be respectively coupled to the both side surfaces of the air knife 10 and may be rotated together with the air knife 10. A center of the first gas supply pipe 15A and a center of the second gas supply pipe 15B coincide with each other when the first and second gas supply pipes 15A and 15B are viewed from a side direction thereof, so that the pipe center 15c is capable of being provided.

[0022] The body 20 may include a flow path for transferring the gas, and the flow path may be connected to a high pressure gas providing source (not illustrated) that provides the gas. The body 20 may include a frame having a duct structure providing the flow path. A position of the frame having the duct structure may be fixed by a mounting frame (not illustrated).

[0023] In FIG. 1, the reference numeral 30 is a gas transferring pipe. The gas transferring pipe 30 connects the first gas supply pipe 15A and the second gas supply pipe 15B to the flow path, so that the gas provided to the flow path from the high pressure gas providing source may be introduced into the gas transferring pipe and may be discharged to the first gas supply pipe 15A and the second gas supply pipe 15B. The gas is introduced into the air knife 10 through the first gas supply pipe 15A and the second gas supply pipe 15B, and the gas is capable of being jetted to the plated steel sheet through the air knife 10.

[0024] The gas transferring pipe 30 is a pipe connected to an end of the first gas supply pipe 15A and an end of the second gas supply pipe 15B, and may include an elbow. The end of the first gas supply pipe 15A and the end of the second gas supply pipe 15B may be fitted and coupled to the elbow such that the first gas supply pipe 15A and the second gas supply pipe 15B are capable of being rotated around the pipe center 15c.

[0025] Referring to FIGS. 2 to 5, the angle adjusting apparatus 110 may include: a fixing body 111 provided on a first surface (otherwise, a second surface at a right side facing the air knife 10) at a left side among both side surfaces of the first bracket 21A, the fixing body 111 being positioned at a front side (otherwise, a rear side) of the first gas supply pipe 15A; a screw shaft 112 provided at the fixing body 111 such that the screw shaft 112 is capable of being rotated around an axis A1 of a vertical direction, the screw shaft 112 having an outer circumference provided with an external thread 112t; a moving body 113 provided with an internal thread 113t that corresponds to the external thread 112t of the screw shaft 112, the moving body 113 being screw coupled to the screw shaft 112 and being capable of moving in the vertical direction according to a rotation direction of the screw shaft 112; a shaft driving unit 114 configured to rotate the screw shaft 112 in frontward and rearward; a shaft member 115 provided at a left side portion of the moving body 113 such that the shaft member 115 is capable of being rotated around an axis A2 of the left and right directions; a rotating body 116 provided on the shaft member 115 and configured to be rotated together with the shaft member 115; a movable rail (a slider) 117 having a rectilinear shape, the movable rail 117 being provided on the rotating body 116 such that the movable rail 117 is capable of being moved along a radial direction of the pipe center 15c; and an angle adjusting lever 118 having both sides thereof provided with a first end portion 118a and a second end portion 118b that are respectively coupled to the first gas supply pipe 15A and the movable rail 117.

[0026] Referring to FIG. 3, the fixing body 111 may be formed such that a size of the fixing body 111 in the vertical direction is similar to a length of the screw shaft 112. An upper end portion of the fixing body 111 may be provided with a rotation supporting element 111b such as a bearing that supports an upper head of the screw shaft 112 such that the upper head of the screw shaft 112 is capable of being rotated.

[0027] A lower body of the screw shaft 112 may have the external thread 112t, and the moving body 113 may have a thread hole which penetrates in the vertical direction and in which the internal thread 113t is formed. The moving body 113 may be formed in a shape in which a rotation of the moving body 113 performed together with the screw shaft 112 is limited by being in contact with the fixing body 111 and so on.

[0028] Referring to FIG. 1, FIG. 2, and so on, the shaft driving unit 114 may include: a driving motor 114a configured to provide a rotation force; a decelerator 114b configured to decelerate and output a rotation speed of the driving motor 114; and a power transmission shaft 114c configured to transmit a rotational force output from the decelerator 114b to the screw shaft 112.

[0029] For example, the driving motor 114a may be mounted on the frame of the body 20, the frame having the duct structure. The decelerator 114b may be provided with an input shaft connected to the driving motor 114a and an output shaft connected to the power transmission shaft 114c, and may be provided with a plurality of gears provided between the input shaft and the output shaft so as to decelerate the rotation speed of the driving motor 114a. According to a positional relationship between the decelerator 114b and the screw shaft 112, the power transmission shaft 114c may include a universal joint.

[0030] In such a shaft driving unit 114, the driving motor 114a and the decelerator 114b may be controlled by a clutch and so on, and a handle for performing a manual operation may be connected to the input shaft of the decelerator 114b. Therefore, if necessary, after a power transmission between the driving motor 114a and the decelerator 114b is blocked, the screw shaft 112 may be rotated by using the handle.

[0031] Referring to FIG. 3, the shaft member 115, the rotating body 116, and the movable rail 117 constitute a power transmission unit. That is, the shaft member 115, the rotating body 116, and the movable rail 117 connect the movable body 113 to the second end portion 118b of the angle adjusting lever 118 from between the moving body 113 and the angle adjusting lever 118, and may rotate the angle adjusting lever 118 by transmitting a moving force in the vertical direction of the moving body 113 to the angle adjusting lever 118. Referring to FIG. 1, FIG. 4, and so on, in the angle adjusting lever 118, among a first surface at a left side of the second end portion 118b and a second surface at a right side of the second end portion 118b, the second surface at the right side of the second end portion 118b (otherwise, the first surface at the left side) may be connected to the movable rail 117.

[0032] The movable rail 117 may have a base portion and a rail portion on the base portion. The base portion of the movable rail 117 may be coupled to the second end portion 118b of the angle adjusting lever 118, and the rail portion of the movable rail 117 may be coupled to the rotating body 116 such that the movable rail 117 is capable of being slidably moved. The rotating body 116 may have a sliding groove 116g (see FIG. 5) to which the rail portion of the movable rail 117 is coupled such that the movable rail 117 is capable of being slidably moved. Referring to FIGS. 4 and 5, the sliding groove 116g of the rotating body 116 may be formed to be orthogonal to the axis A2 of the left and right directions.

[0033] As illustrated in FIGS. 4 and 5, the angle adjusting lever 118 may be rotated together with the first gas supply pipe 15A while the first end portion 118a is fitted and fixed to an outer circumference of the first gas supply pipe 15A. An insertion hole 118h (see FIG. 6) which penetrates the first end portion 118a in the left and right directions and to which the first gas supply pipe 15A is fitted may be formed in the angle adjusting lever 118.

[0034] Referring to FIG. 4 and so on, in order for the angle adjusting lever 118 to be easily coupled to the first gas supply pipe 15A, the angle adjusting lever 118 is divided into a first unit body 118-1 and a second unit body 1182 on the basis of a center (see the pipe center 15c) of the insertion hole 118h, the first unit body 118-1 including a part of the first end portion 118a and the second unit body 118-2 including a remaining part of the first end portion 118a and the second end portion 118b. Furthermore, the first unit body 118-1 and the second unit body 118-2 may be assembled with each other by a bolt 118-3 (see FIG. 6) such that the first unit body 118-1 and the second unit body 118-2 provide the insertion hole 118h. The first unit body 118-1 and the second unit body 118-2 may press the first gas supply pipe 15A by tightening the bolt 118-3, the first gas supply pipe 15A being fitted into the insertion hole 118h. As illustrated in FIG. 6, in order to increase a coupling force with the first gas supply pipe 15A, the angle adjusting lever 118 may have at least one fixing protrusion 118p that protrudes from an inner circumference of the insertion hole 118h.

[0035] When the screw shaft 112 is rotated around the axis A1 of the vertical direction by the shaft driving unit 114, the moving body 113 may be moved upward or downward according to the axis of the vertical direction. Furthermore, the angle adjusting lever 118 may be rotated upward or downward on the basis of the pipe center 15c by receiving a moving force of the moving body 113 through the shaft member 115, the rotating body 116, and the movable rail 117. During this process, in the power transmission unit interposed between the moving body 113 capable of being rectilinearly moved and the angle adjusting lever 118 capable of being rotated, the shaft member 115 and the rotating body 116 are rotated around the axis A2 in the left and right directions. In addition, the movable rail 117 is moved along the radial direction of the pipe center 15c, and changes a connection position of the second end portion 118b with respect to the rotating body 116, so that a rotation according to a rotation radius of the angle adjusting lever 118 may be realized.

[0036] Specifically, when the moving body 113 is moved upward or downward, the shaft member 115 and the rotating body 116 may be rotated upward or downward around the axis A2 in the left and right directions while being moved together with the moving body 113. Furthermore, while the movable rail 117 is moved together with the moving body 113 and is moved together with the rotating body 116 (that is, the movable rail 117 is rotated such that a length direction thereof corresponds to the radial direction of the pipe center 15c according to a vertical position change), the movable rail 117 may be moved along the radial direction of the pipe center 15c such that the movable rail 117 is spaced apart from or close to the pipe center 15c (see FIGS. 4 and 5) . At this time, as the angle adjusting lever 118 is rotated upward or downward with respect to the pipe center 15c, the angle adjusting lever 118 rotates the first gas supply pipe 15A upward or downward with respect to the pipe center 15c, so that the air knife 10 is capable of being rotated upward or downward with respect to the pipe center 15c. Accordingly, in the air knife system according to an embodiment of the present disclosure, a vertical angle of the air knife 10 with respect to the plated steel sheet is capable of being changed to a desired angle.

[0037] In FIG. 4, as the moving member 113 is moved downward, the shaft member 115 and the rotating body 116 are rotated downward, and the movable rail 117 is moved in a direction approaching the pipe center 15c, a state in which the first gas supply pipe 15A is rotated downward with respect to the pipe center 15c and an angle of the air knife 10 with respect to the plated steel sheet is adjusted downward is illustrated. Conversely, in FIG. 5, as the moving member 113 is moved upward, the shaft member 115 and the rotating body 116 are rotated upward, and the movable rail 117 is moved in a direction spaced apart from the pipe center 15c, a state in which the first gas supply pipe 15A is rotated upward with respect to the pipe center 15c and an angle of the air knife 10 with respect to the plated steel sheet is adjusted upward is illustrated.

[0038] The first angle measurement apparatus 120 may display a rotation angle of the air knife 10 so that a worker and so on are capable of checking the rotation angle, in which the rotation angle is adjusted by the angle adjusting apparatus 110.

[0039] Referring to FIGS. 1 to 6, the first angle measurement apparatus 120 may include: a first gear member 122 provided on the angle adjusting lever 118 and provided with a gear teeth of a pinion that is provided along the outer circumference with respect to the pipe center 15c, the first gear member 122 having the gear teeth disposed at a front side or a rear side of the first gas supply pipe 15A; a second gear member 123 that extends in the vertical direction such that an upper end portion of the second gear member 123 is positioned adjacent to the body 20, the second gear member 123 having a lower end portion provided with a gear teeth of a rack engaged with the gear teeth of the first gear member 122; a guide module (see reference numerals 121, 126, and 127) connected to the fixing body 111 and configured to support the second gear member 123 such that the second gear member 123 is capable of being moved in the vertical direction; a scale body 125 provided on the body 20 and disposed adjacent to the upper end portion of the second gear member 123, the scale body 125 being provided with a scale for indicating a rotation angle of the air knife 10; and a scale indicator 124 provided on the upper end portion of the second gear member 123 and being configured to be moved in the vertical direction according to a rotation of the angle adjusting lever 118, thereby indicating the scale that corresponds to a rotation angle of the air knife 10.

[0040] According to the first angle measurement apparatus 120, when the angle adjusting apparatus 110 is operated and the angle adjusting lever 118 is rotated so as to adjust an angle of the air knife 10, the first gear member 122 is rotated together with the angle adjusting lever 118 with respect to the pipe center 15c, and the second gear member 123 is moved upward or downward. Furthermore, since the scale indicator 124 is moved together with the second gear member 123 and the scale corresponding to the rotation angle of the air knife 10 is indicated, the worker and so on are capable of checking the rotation angle of the air knife 10 through the scale indicated by the scale indicator 124.

[0041] The first gear member 122 may be disposed on the first surface at the left side (otherwise, the second surface at the right side) of the angle adjusting lever 118, and may be rotated together with the angle adjusting lever 118.

[0042] The guide module may be positioned at an opposite side of the fixing body 111 on the basis of the angle adjusting lever 118. Accordingly, the angle adjusting lever 118 may be positioned between the fixing body 111 and the guide module.

[0043] Referring to FIG. 6, the guide module may include: an auxiliary body 121 connected to the fixing body 111 such that a position of the auxiliary body 121 is fixed; a supporting member 126 provided with a guide hole that supports the second gear member 123 such that the second gear member 123 is capable of being moved in the vertical direction; and at least one elastic member 127 providing elastic force toward the first gear member 122 to the supporting member 126 from between the auxiliary body 121 and the supporting member 126, thereby bringing the gear teeth of the first gear member 122 into close contact with the gear teeth of the second gear member 123.

[0044] The elastic member 127 may be a spring. The elastic member 127 elastically pushes the second gear member 123 toward the first gear member 122 by using the support member 126, thereby being capable of preventing a backlash that may occur between the gear teeth of the first gear member 122 and the gear teeth of the second gear member 123. Accordingly, a measurement of a rotation angle of the air knife 10 that uses the first gear member 122 and the second gear member 123 may be more accurately performed.

[0045] Meanwhile, as illustrated in FIG. 6, an insertion groove 123a may be formed in the second gear member 123 in the vertical direction, and an insertion protrusion 126a inserted into the insertion groove 123a such that the insertion protrusion 126a is capable of being slidably moved along the insertion groove 123a may be formed on the guide hole of the supporting member 126. The insertion groove 123a and the insertion protrusion 126a may guide the second gear member 123 to be more stably moved in the vertical direction without shaking.

[0046] The second angle adjusting apparatus 130 may measure a rotation angle of the air knife 10 and may provide a measured result to an operation room, in which the rotation angle is adjusted by the angle adjusting apparatus 110.

[0047] Referring to FIG. 7, the second angle measurement apparatus 130 may include: a measurement jig 131 provided on the second gas supply pipe 15B and provided with a first gear teeth 131a along the outer circumference with respect to the pipe center 15c; a measurement module 132 provided with a rotation element having an outer circumference provided with a second gear teeth 132a that is engaged with the first gear teeth 131a, the measurement module 132 being configured to detect the rotation amount of the rotation element so as to measure the rotation angle of the air knife 10 and being configured to transmit a detected value to the operation room in a wired manner or a wireless manner; a module holder 135 having the measurement module 132, the module holder 135 being provided such that the module holder 135 is capable of being rotated around a hinge shaft 136 that is parallel to the pipe center 15c, and the module holder 135 being configured to space the rotation element apart from or approach the measurement jig according to a rotation direction of the module holder 135; a mounting block 137 provided on the second bracket 21B, the mounting block 137 having the hinge shaft 136 and being disposed such that the module holder 135 is positioned between the mounting block 137 and the measurement jig 131; and at least one elastic member 138 providing elastic force toward the measurement jig 131 to the module holder 135 from between the module holder 135 and the mounting block 137, thereby bringing the first gear teeth 131a into close contact with the second gear teeth 132a.

[0048] The measurement jig 131 may be disposed at a right side (otherwise, a left side) on the basis of the second bracket 21B. Accordingly, the mounting block 137 may be coupled to a second surface at the right side (otherwise, a first surface at a left side facing the air knife 10) among both side surfaces of the second bracket 21B.

[0049] The measurement module 132 may be provided with an encoder and so on so as to detect the rotation amount of the rotation element. The rotation element of the measurement module 132 may be a spur gear, so that the first gear teeth 131a may be a gear teeth of a spur gear. The rotation element may have a rotation radius smaller than a rotation radius of the measurement jig 131.

[0050] Meanwhile, the measurement jig 131 may be rotated together with the second gas supply pipe 15B while being fitted and fixed to the outer circumference of the second gas supply pipe 15B. In order for the measurement jig 131 to be easily coupled to the second gas supply pipe 15B, the measurement jig 131 is divided into two parts with respect to the pipe center 15c and the two parts are engaged with each other by a bolt, and the second gas supply pipe 15B may be pressed by tightening the bolt.

[0051] The elastic member 138 of the second angle measurement apparatus 130 may be a spring. The elastic member 138 elastically pushes the rotation element (spur gear) of the measurement module 132 toward the first gear teeth 131a of the measurement jig 131 through the module holder 135, thereby being capable of preventing a backlash that may occur between the first gear teeth 131a and the second gear teeth 132a. Accordingly, a measurement of a rotation angle of the air knife which uses the measurement jig 131 having the first gear teeth 131a and which uses the measurement module 132 having the second gear teeth 132a may be more accurately performed.

[0052] In FIG. 7, reference numerals 133, 134A, and 134B are a sensing module for sensing an upper limit rotation angle and a lower limit rotation angle of the air knife 10. The sensing module may be used for preventing the air knife 10 from being rotated beyond an allowable range by the angle adjusting apparatus 110.

[0053] The reference numeral 133 is a reference member provided on the measurement jig 131, and reference numerals 134A and 134B are a first sensor and a second sensor that are respectively sensing whether the reference member 133 rotated together with the measurement jig 131 is positioned at a position corresponding to the upper limit rotation angle and the lower limit rotation angle of the air knife 10.

[0054] The first sensor 134A and the second sensor 134B may be contact type sensors such as limit switches. Otherwise, the first sensor 134A and the second sensor 134B may be non-contact type sensors such as optical sensors. For example, when the optical sensors are used, the reference member 133 may be configured such that the reference member 133 is capable of reflecting light from the first sensor 134A and the second sensor 134B.

[0055] While the present disclosure has been described above, the present disclosure is not limited to the disclosed embodiment and the accompanying drawings, and those skilled in the art may variously modify the present disclosure without departing from the technical features of the present disclosure.

Claims

1. An air knife system comprising:

an air knife jetting gas to a plated steel sheet;

a first gas supply pipe and a second gas supply pipe which respectively extend along left and right directions from corresponding positions of both side surfaces of the air knife and which respectively protrude to left and right sides of the air knife;

a body mounted above the air knife and provided with a first bracket and a second bracket which respectively support the first gas supply pipe and the second gas supply pipe such that the first gas supply pipe and the second gas supply pipe are capable of being rotated around a pipe center; and

an angle adjusting apparatus configured to adjust a vertical angle of the air knife with respect to the plated steel sheet by rotating the first gas supply pipe so that the air knife is rotated around the pipe center,

wherein the angle adjusting apparatus comprises:

a fixing body provided on the first bracket, the fixing body being positioned at a front side or a rear side of the first gas supply pipe;

a screw shaft provided at the fixing body such that the screw shaft is capable of being rotated around an axis of a vertical direction, the screw shaft being configured to be rotated by a shaft driving unit;

a moving body that is screw coupled to the screw shaft, the moving body being capable of moving in the vertical direction according to a rotation direction of the screw shaft; and

an angle adjusting lever provided with a first end portion coupled to the first gas supply pipe, the angle adjusting lever being provided with a second end portion connected to the moving body through a power transmission unit,

wherein the power transmission unit is configured to rotate the angle adjusting lever by transmitting a moving force of the moving body to the angle adjusting lever.

2. The air knife system of claim 1, wherein the power transmission unit comprises:

a shaft member provided on the moving body such that the shaft member is capable of being rotated around an axis of the left and right directions;

a rotating body provided on the shaft member and configured to be rotated together with the shaft member; and

a slider provided on the rotating body such that the slider is capable of being moved along a radial direction of the pipe center, the slider being coupled to the second end portion of the angle adjusting lever.

3. The air knife system of claim 1 or claim 2, wherein the shaft driving unit comprises:

a driving motor;

a decelerator configured to decelerate a rotation speed of the driving motor; and

a power transmission shaft configured to transmit a rotational force output from the decelerator to the screw shaft.

4. The air knife system of claim 1 or claim 2, further comprising a first angle measurement apparatus,
wherein the first angle measurement apparatus comprises:

a first gear member provided on the angle adjusting lever and provided with a gear teeth of a pinion provided along an outer circumference with respect to the pipe center, the first gear member having the gear teeth disposed at the front side or the rear side of the first gas supply pipe;

a second gear member that extends in the vertical direction such that an upper end portion of the second gear member is positioned at a side of the body, the second gear member having a lower end portion provided with a gear teeth of a rack engaged with the gear teeth of the first gear member;

a guide module connected to the fixing body and configured to support the second gear member such that the second gear member is capable of being moved in the vertical direction;

a scale body provided on the body such that the scale body is positioned at a side of an upper end portion of the second gear member, the scale body being provided with a scale for indicating a rotation angle of the air knife; and

a scale indicator provided on the upper end portion of the second gear member, the scale indicator being configured to be moved in the vertical direction according to a rotation of the angle adjusting lever, thereby indicating the scale.

5. The air knife system of claim 4, wherein the guide module comprises:

an auxiliary body connected to the fixing body;

a supporting member supporting the second gear member such that the second gear member is capable of being moved in the vertical direction; and

at least one elastic member providing elastic force toward the first gear member to the supporting member from between the auxiliary body and the supporting member.

6. The air knife system of claim 1 or claim 2, further comprising a second angle measurement apparatus,
wherein the second angle measurement apparatus comprises:

a measurement jig provided on the second gas supply pipe and provided with a first gear teeth along an outer circumference with respect to the pipe center;

a measurement module provided with a rotation element having an outer circumference provided with a second gear teeth that is engaged with the first gear teeth, the measurement module being configured to detect a rotation amount of the rotation element;

a module holder having the measurement module, the module holder being provided such that the module holder is capable of being rotated around a hinge shaft that is parallel to the pipe center, and the module holder being configured to space the rotation element apart from or approach the measurement jig according to a rotation direction;

a mounting block provided on the second bracket, the mounting block having the hinge shaft and being disposed such that the module holder is positioned between the mounting block and the measurement jig; and

at least one elastic member providing elastic force toward the measurement jig to the module holder from between the module holder and the mounting block.

Drawing